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2024-05-24mm/vmalloc: fix vmalloc which may return null if called with __GFP_NOFAILHailong.Liu1-3/+2
commit a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc") includes support for __GFP_NOFAIL, but it presents a conflict with commit dd544141b9eb ("vmalloc: back off when the current task is OOM-killed"). A possible scenario is as follows: process-a __vmalloc_node_range(GFP_KERNEL | __GFP_NOFAIL) __vmalloc_area_node() vm_area_alloc_pages() --> oom-killer send SIGKILL to process-a if (fatal_signal_pending(current)) break; --> return NULL; To fix this, do not check fatal_signal_pending() in vm_area_alloc_pages() if __GFP_NOFAIL set. This issue occurred during OPLUS KASAN TEST. Below is part of the log -> oom-killer sends signal to process [65731.222840] [ T1308] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom,task_memcg=/apps/uid_10198,task=gs.intelligence,pid=32454,uid=10198 [65731.259685] [T32454] Call trace: [65731.259698] [T32454] dump_backtrace+0xf4/0x118 [65731.259734] [T32454] show_stack+0x18/0x24 [65731.259756] [T32454] dump_stack_lvl+0x60/0x7c [65731.259781] [T32454] dump_stack+0x18/0x38 [65731.259800] [T32454] mrdump_common_die+0x250/0x39c [mrdump] [65731.259936] [T32454] ipanic_die+0x20/0x34 [mrdump] [65731.260019] [T32454] atomic_notifier_call_chain+0xb4/0xfc [65731.260047] [T32454] notify_die+0x114/0x198 [65731.260073] [T32454] die+0xf4/0x5b4 [65731.260098] [T32454] die_kernel_fault+0x80/0x98 [65731.260124] [T32454] __do_kernel_fault+0x160/0x2a8 [65731.260146] [T32454] do_bad_area+0x68/0x148 [65731.260174] [T32454] do_mem_abort+0x151c/0x1b34 [65731.260204] [T32454] el1_abort+0x3c/0x5c [65731.260227] [T32454] el1h_64_sync_handler+0x54/0x90 [65731.260248] [T32454] el1h_64_sync+0x68/0x6c [65731.260269] [T32454] z_erofs_decompress_queue+0x7f0/0x2258 --> be->decompressed_pages = kvcalloc(be->nr_pages, sizeof(struct page *), GFP_KERNEL | __GFP_NOFAIL); kernel panic by NULL pointer dereference. erofs assume kvmalloc with __GFP_NOFAIL never return NULL. [65731.260293] [T32454] z_erofs_runqueue+0xf30/0x104c [65731.260314] [T32454] z_erofs_readahead+0x4f0/0x968 [65731.260339] [T32454] read_pages+0x170/0xadc [65731.260364] [T32454] page_cache_ra_unbounded+0x874/0xf30 [65731.260388] [T32454] page_cache_ra_order+0x24c/0x714 [65731.260411] [T32454] filemap_fault+0xbf0/0x1a74 [65731.260437] [T32454] __do_fault+0xd0/0x33c [65731.260462] [T32454] handle_mm_fault+0xf74/0x3fe0 [65731.260486] [T32454] do_mem_abort+0x54c/0x1b34 [65731.260509] [T32454] el0_da+0x44/0x94 [65731.260531] [T32454] el0t_64_sync_handler+0x98/0xb4 [65731.260553] [T32454] el0t_64_sync+0x198/0x19c Link: https://lkml.kernel.org/r/20240510100131.1865-1-hailong.liu@oppo.com Fixes: 9376130c390a ("mm/vmalloc: add support for __GFP_NOFAIL") Signed-off-by: Hailong.Liu <hailong.liu@oppo.com> Acked-by: Michal Hocko <mhocko@suse.com> Suggested-by: Barry Song <21cnbao@gmail.com> Reported-by: Oven <liyangouwen1@oppo.com> Reviewed-by: Barry Song <baohua@kernel.org> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Chao Yu <chao@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Gao Xiang <xiang@kernel.org> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-19Merge tag 'mm-stable-2024-05-17-19-19' of ↵Linus Torvalds1-66/+72
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...
2024-05-06mm: vmalloc: dump page owner info if page is already mappedHariom Panthi1-1/+9
In vmap_pte_range, BUG_ON is called when page is already mapped, It doesn't give enough information to debug further. Dumping page owner information alongwith BUG_ON will be more useful in case of multiple page mapping. Example: [ 14.552875] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10b923 [ 14.553440] flags: 0xbffff0000000000(node=0|zone=2|lastcpupid=0x3ffff) [ 14.554001] page_type: 0xffffffff() [ 14.554783] raw: 0bffff0000000000 0000000000000000 dead000000000122 0000000000000000 [ 14.555230] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 [ 14.555768] page dumped because: remapping already mapped page [ 14.556172] page_owner tracks the page as allocated [ 14.556482] page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL), pid 80, tgid 80 (insmod), ts 14552004992, free_ts 0 [ 14.557286] prep_new_page+0xa8/0x10c [ 14.558052] get_page_from_freelist+0x7f8/0x1248 [ 14.558298] __alloc_pages+0x164/0x2b4 [ 14.558514] alloc_pages_mpol+0x88/0x230 [ 14.558904] alloc_pages+0x4c/0x7c [ 14.559157] load_module+0x74/0x1af4 [ 14.559361] __do_sys_init_module+0x190/0x1fc [ 14.559615] __arm64_sys_init_module+0x1c/0x28 [ 14.559883] invoke_syscall+0x44/0x108 [ 14.560109] el0_svc_common.constprop.0+0x40/0xe0 [ 14.560371] do_el0_svc_compat+0x1c/0x34 [ 14.560600] el0_svc_compat+0x2c/0x80 [ 14.560820] el0t_32_sync_handler+0x90/0x140 [ 14.561040] el0t_32_sync+0x194/0x198 [ 14.561329] page_owner free stack trace missing [ 14.562049] ------------[ cut here ]------------ [ 14.562314] kernel BUG at mm/vmalloc.c:113! Link: https://lkml.kernel.org/r/20240424111838.3782931-2-hariom1.p@samsung.com Signed-off-by: Hariom Panthi <hariom1.p@samsung.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Maninder Singh <maninder1.s@samsung.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rohit Thapliyal <r.thapliyal@samsung.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-06mm/vmalloc: fix return value of vb_alloc if size is 0Hailong.Liu1-1/+1
vm_map_ram() uses IS_ERR() to validate the return value of vb_alloc(). If vm_map_ram(page, 0, 0) is executed, vb_alloc(0, GFP_KERNEL) would return NULL. In such a case, IS_ERR() cannot handle the return value and lead to kernel panic by vmap_pages_range_noflush() at last. To resolve this issue, return ERR_PTR(-EINVAL) if the size is 0. Link: https://lkml.kernel.org/r/20240426024149.21176-1-hailong.liu@oppo.com Reviewed-by: Barry Song <baohua@kernel.org> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Hailong.Liu <hailong.liu@oppo.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-26mm/vmalloc.c: optimize to reduce arguments of alloc_vmap_area()Baoquan He1-8/+12
If called by __get_vm_area_node(), by open coding the field assignments of 'struct vm_struct *vm', and move the vm->flags and vm->caller assignments into __get_vm_area_node(), the passed in arguments 'flags' and 'caller' can be removed. This alleviates overloaded arguments passed in for alloc_vmap_area(). Link: https://lkml.kernel.org/r/20240309044454.648888-1-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-26mm/vmalloc: eliminated the lock contention from twice to oncerulinhuang1-28/+22
When allocating a new memory area where the mapping address range is known, it is observed that the vmap_node->busy.lock is acquired twice. The first acquisition occurs in the alloc_vmap_area() function when inserting the vm area into the vm mapping red-black tree. The second acquisition occurs in the setup_vmalloc_vm() function when updating the properties of the vm, such as flags and address, etc. Combine these two operations together in alloc_vmap_area(), which improves scalability when the vmap_node->busy.lock is contended. By doing so, the need to acquire the lock twice can also be eliminated to once. With the above change, tested on intel sapphire rapids platform(224 vcpu), a 4% performance improvement is gained on stress-ng/pthread(https://github.com/ColinIanKing/stress-ng), which is the stress test of thread creations. Link: https://lkml.kernel.org/r/20240307021440.64967-1-rulin.huang@intel.com Co-developed-by: "Chen, Tim C" <tim.c.chen@intel.com> Signed-off-by: "Chen, Tim C" <tim.c.chen@intel.com> Co-developed-by: "King, Colin" <colin.king@intel.com> Signed-off-by: "King, Colin" <colin.king@intel.com> Signed-off-by: rulinhuang <rulin.huang@intel.com> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Wangyang Guo <wangyang.guo@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-26mm: vmalloc: enable memory allocation profilingKent Overstreet1-37/+37
This wrapps all external vmalloc allocation functions with the alloc_hooks() wrapper, and switches internal allocations to _noprof variants where appropriate, for the new memory allocation profiling feature. [surenb@google.com: arch/um: fix forward declaration for vmalloc] Link: https://lkml.kernel.org/r/20240326073750.726636-1-surenb@google.com [surenb@google.com: undo _noprof additions in the documentation] Link: https://lkml.kernel.org/r/20240326231453.1206227-5-surenb@google.com Link: https://lkml.kernel.org/r/20240321163705.3067592-31-surenb@google.com Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-05mm: vmalloc: fix lockdep warningUladzislau Rezki (Sony)1-30/+43
A lockdep reports a possible deadlock in the find_vmap_area_exceed_addr_lock() function: ============================================ WARNING: possible recursive locking detected 6.9.0-rc1-00060-ged3ccc57b108-dirty #6140 Not tainted -------------------------------------------- drgn/455 is trying to acquire lock: ffff0000c00131d0 (&vn->busy.lock/1){+.+.}-{2:2}, at: find_vmap_area_exceed_addr_lock+0x64/0x124 but task is already holding lock: ffff0000c0011878 (&vn->busy.lock/1){+.+.}-{2:2}, at: find_vmap_area_exceed_addr_lock+0x64/0x124 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&vn->busy.lock/1); lock(&vn->busy.lock/1); *** DEADLOCK *** indeed it can happen if the find_vmap_area_exceed_addr_lock() gets called concurrently because it tries to acquire two nodes locks. It was done to prevent removing a lowest VA found on a previous step. To address this a lowest VA is found first without holding a node lock where it resides. As a last step we check if a VA still there because it can go away, if removed, proceed with next lowest. [akpm@linux-foundation.org: fix comment typos, per Baoquan] Link: https://lkml.kernel.org/r/20240328140330.4747-1-urezki@gmail.com Fixes: 53becf32aec1 ("mm: vmalloc: support multiple nodes in vread_iter") Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Tested-by: Jens Axboe <axboe@kernel.dk> Tested-by: Omar Sandoval <osandov@fb.com> Reported-by: Jens Axboe <axboe@kernel.dk> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-05mm: vmalloc: bail out early in find_vmap_area() if vmap is not initUladzislau Rezki (Sony)1-0/+3
During the boot the s390 system triggers "spinlock bad magic" messages if the spinlock debugging is enabled: [ 0.465445] BUG: spinlock bad magic on CPU#0, swapper/0 [ 0.465490] lock: single+0x1860/0x1958, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 [ 0.466067] CPU: 0 PID: 0 Comm: swapper Not tainted 6.8.0-12955-g8e938e398669 #1 [ 0.466188] Hardware name: QEMU 8561 QEMU (KVM/Linux) [ 0.466270] Call Trace: [ 0.466470] [<00000000011f26c8>] dump_stack_lvl+0x98/0xd8 [ 0.466516] [<00000000001dcc6a>] do_raw_spin_lock+0x8a/0x108 [ 0.466545] [<000000000042146c>] find_vmap_area+0x6c/0x108 [ 0.466572] [<000000000042175a>] find_vm_area+0x22/0x40 [ 0.466597] [<000000000012f152>] __set_memory+0x132/0x150 [ 0.466624] [<0000000001cc0398>] vmem_map_init+0x40/0x118 [ 0.466651] [<0000000001cc0092>] paging_init+0x22/0x68 [ 0.466677] [<0000000001cbbed2>] setup_arch+0x52a/0x708 [ 0.466702] [<0000000001cb6140>] start_kernel+0x80/0x5c8 [ 0.466727] [<0000000000100036>] startup_continue+0x36/0x40 it happens because such system tries to access some vmap areas whereas the vmalloc initialization is not even yet done: [ 0.465490] lock: single+0x1860/0x1958, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 [ 0.466067] CPU: 0 PID: 0 Comm: swapper Not tainted 6.8.0-12955-g8e938e398669 #1 [ 0.466188] Hardware name: QEMU 8561 QEMU (KVM/Linux) [ 0.466270] Call Trace: [ 0.466470] dump_stack_lvl (lib/dump_stack.c:117) [ 0.466516] do_raw_spin_lock (kernel/locking/spinlock_debug.c:87 kernel/locking/spinlock_debug.c:115) [ 0.466545] find_vmap_area (mm/vmalloc.c:1059 mm/vmalloc.c:2364) [ 0.466572] find_vm_area (mm/vmalloc.c:3150) [ 0.466597] __set_memory (arch/s390/mm/pageattr.c:360 arch/s390/mm/pageattr.c:393) [ 0.466624] vmem_map_init (./arch/s390/include/asm/set_memory.h:55 arch/s390/mm/vmem.c:660) [ 0.466651] paging_init (arch/s390/mm/init.c:97) [ 0.466677] setup_arch (arch/s390/kernel/setup.c:972) [ 0.466702] start_kernel (init/main.c:899) [ 0.466727] startup_continue (arch/s390/kernel/head64.S:35) [ 0.466811] INFO: lockdep is turned off. ... [ 0.718250] vmalloc init - busy lock init 0000000002871860 [ 0.718328] vmalloc init - busy lock init 00000000028731b8 Some background. It worked before because the lock that is in question was statically defined and initialized. As of now, the locks and data structures are initialized in the vmalloc_init() function. To address that issue add the check whether the "vmap_initialized" variable is set, if not find_vmap_area() bails out on entry returning NULL. Link: https://lkml.kernel.org/r/20240323141544.4150-1-urezki@gmail.com Fixes: 72210662c5a2 ("mm: vmalloc: offload free_vmap_area_lock lock") Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-15Merge tag 'mm-stable-2024-03-13-20-04' of ↵Linus Torvalds1-267/+813
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames from hotplugged memory rather than only from main memory. Series "implement "memmap on memory" feature on s390". - More folio conversions from Matthew Wilcox in the series "Convert memcontrol charge moving to use folios" "mm: convert mm counter to take a folio" - Chengming Zhou has optimized zswap's rbtree locking, providing significant reductions in system time and modest but measurable reductions in overall runtimes. The series is "mm/zswap: optimize the scalability of zswap rb-tree". - Chengming Zhou has also provided the series "mm/zswap: optimize zswap lru list" which provides measurable runtime benefits in some swap-intensive situations. - And Chengming Zhou further optimizes zswap in the series "mm/zswap: optimize for dynamic zswap_pools". Measured improvements are modest. - zswap cleanups and simplifications from Yosry Ahmed in the series "mm: zswap: simplify zswap_swapoff()". - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has contributed several DAX cleanups as well as adding a sysfs tunable to control the memmap_on_memory setting when the dax device is hotplugged as system memory. - Johannes Weiner has added the large series "mm: zswap: cleanups", which does that. - More DAMON work from SeongJae Park in the series "mm/damon: make DAMON debugfs interface deprecation unignorable" "selftests/damon: add more tests for core functionalities and corner cases" "Docs/mm/damon: misc readability improvements" "mm/damon: let DAMOS feeds and tame/auto-tune itself" - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs extension" Rakie Kim has developed a new mempolicy interleaving policy wherein we allocate memory across nodes in a weighted fashion rather than uniformly. This is beneficial in heterogeneous memory environments appearing with CXL. - Christophe Leroy has contributed some cleanup and consolidation work against the ARM pagetable dumping code in the series "mm: ptdump: Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute". - Luis Chamberlain has added some additional xarray selftesting in the series "test_xarray: advanced API multi-index tests". - Muhammad Usama Anjum has reworked the selftest code to make its human-readable output conform to the TAP ("Test Anything Protocol") format. Amongst other things, this opens up the use of third-party tools to parse and process out selftesting results. - Ryan Roberts has added fork()-time PTE batching of THP ptes in the series "mm/memory: optimize fork() with PTE-mapped THP". Mainly targeted at arm64, this significantly speeds up fork() when the process has a large number of pte-mapped folios. - David Hildenbrand also gets in on the THP pte batching game in his series "mm/memory: optimize unmap/zap with PTE-mapped THP". It implements batching during munmap() and other pte teardown situations. The microbenchmark improvements are nice. - And in the series "Transparent Contiguous PTEs for User Mappings" Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte mappings"). Kernel build times on arm64 improved nicely. Ryan's series "Address some contpte nits" provides some followup work. - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has fixed an obscure hugetlb race which was causing unnecessary page faults. He has also added a reproducer under the selftest code. - In the series "selftests/mm: Output cleanups for the compaction test", Mark Brown did what the title claims. - Kinsey Ho has added the series "mm/mglru: code cleanup and refactoring". - Even more zswap material from Nhat Pham. The series "fix and extend zswap kselftests" does as claimed. - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX regression" Mathieu Desnoyers has cleaned up and fixed rather a mess in our handling of DAX on archiecctures which have virtually aliasing data caches. The arm architecture is the main beneficiary. - Lokesh Gidra's series "per-vma locks in userfaultfd" provides dramatic improvements in worst-case mmap_lock hold times during certain userfaultfd operations. - Some page_owner enhancements and maintenance work from Oscar Salvador in his series "page_owner: print stacks and their outstanding allocations" "page_owner: Fixup and cleanup" - Uladzislau Rezki has contributed some vmalloc scalability improvements in his series "Mitigate a vmap lock contention". It realizes a 12x improvement for a certain microbenchmark. - Some kexec/crash cleanup work from Baoquan He in the series "Split crash out from kexec and clean up related config items". - Some zsmalloc maintenance work from Chengming Zhou in the series "mm/zsmalloc: fix and optimize objects/page migration" "mm/zsmalloc: some cleanup for get/set_zspage_mapping()" - Zi Yan has taught the MM to perform compaction on folios larger than order=0. This a step along the path to implementaton of the merging of large anonymous folios. The series is named "Enable >0 order folio memory compaction". - Christoph Hellwig has done quite a lot of cleanup work in the pagecache writeback code in his series "convert write_cache_pages() to an iterator". - Some modest hugetlb cleanups and speedups in Vishal Moola's series "Handle hugetlb faults under the VMA lock". - Zi Yan has changed the page splitting code so we can split huge pages into sizes other than order-0 to better utilize large folios. The series is named "Split a folio to any lower order folios". - David Hildenbrand has contributed the series "mm: remove total_mapcount()", a cleanup. - Matthew Wilcox has sought to improve the performance of bulk memory freeing in his series "Rearrange batched folio freeing". - Gang Li's series "hugetlb: parallelize hugetlb page init on boot" provides large improvements in bootup times on large machines which are configured to use large numbers of hugetlb pages. - Matthew Wilcox's series "PageFlags cleanups" does that. - Qi Zheng's series "minor fixes and supplement for ptdesc" does that also. S390 is affected. - Cleanups to our pagemap utility functions from Peter Xu in his series "mm/treewide: Replace pXd_large() with pXd_leaf()". - Nico Pache has fixed a few things with our hugepage selftests in his series "selftests/mm: Improve Hugepage Test Handling in MM Selftests". - Also, of course, many singleton patches to many things. Please see the individual changelogs for details. * tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits) mm/zswap: remove the memcpy if acomp is not sleepable crypto: introduce: acomp_is_async to expose if comp drivers might sleep memtest: use {READ,WRITE}_ONCE in memory scanning mm: prohibit the last subpage from reusing the entire large folio mm: recover pud_leaf() definitions in nopmd case selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements selftests/mm: skip uffd hugetlb tests with insufficient hugepages selftests/mm: dont fail testsuite due to a lack of hugepages mm/huge_memory: skip invalid debugfs new_order input for folio split mm/huge_memory: check new folio order when split a folio mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure mm: add an explicit smp_wmb() to UFFDIO_CONTINUE mm: fix list corruption in put_pages_list mm: remove folio from deferred split list before uncharging it filemap: avoid unnecessary major faults in filemap_fault() mm,page_owner: drop unnecessary check mm,page_owner: check for null stack_record before bumping its refcount mm: swap: fix race between free_swap_and_cache() and swapoff() mm/treewide: align up pXd_leaf() retval across archs mm/treewide: drop pXd_large() ...
2024-03-11mm: Introduce vmap_page_range() to map pages in PCI address spaceAlexei Starovoitov1-8/+15
ioremap_page_range() should be used for ranges within vmalloc range only. The vmalloc ranges are allocated by get_vm_area(). PCI has "resource" allocator that manages PCI_IOBASE, IO_SPACE_LIMIT address range, hence introduce vmap_page_range() to be used exclusively to map pages in PCI address space. Fixes: 3e49a866c9dc ("mm: Enforce VM_IOREMAP flag and range in ioremap_page_range.") Reported-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/bpf/CANiq72ka4rir+RTN2FQoT=Vvprp_Ao-CvoYEkSNqtSY+RZj+AA@mail.gmail.com
2024-03-07mm: Introduce VM_SPARSE kind and vm_area_[un]map_pages().Alexei Starovoitov1-2/+57
vmap/vmalloc APIs are used to map a set of pages into contiguous kernel virtual space. get_vm_area() with appropriate flag is used to request an area of kernel address range. It's used for vmalloc, vmap, ioremap, xen use cases. - vmalloc use case dominates the usage. Such vm areas have VM_ALLOC flag. - the areas created by vmap() function should be tagged with VM_MAP. - ioremap areas are tagged with VM_IOREMAP. BPF would like to extend the vmap API to implement a lazily-populated sparse, yet contiguous kernel virtual space. Introduce VM_SPARSE flag and vm_area_map_pages(area, start_addr, count, pages) API to map a set of pages within a given area. It has the same sanity checks as vmap() does. It also checks that get_vm_area() was created with VM_SPARSE flag which identifies such areas in /proc/vmallocinfo and returns zero pages on read through /proc/kcore. The next commits will introduce bpf_arena which is a sparsely populated shared memory region between bpf program and user space process. It will map privately-managed pages into a sparse vm area with the following steps: // request virtual memory region during bpf prog verification area = get_vm_area(area_size, VM_SPARSE); // on demand vm_area_map_pages(area, kaddr, kend, pages); vm_area_unmap_pages(area, kaddr, kend); // after bpf program is detached and unloaded free_vm_area(area); Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Link: https://lore.kernel.org/bpf/20240305030516.41519-3-alexei.starovoitov@gmail.com
2024-03-06mm: Enforce VM_IOREMAP flag and range in ioremap_page_range.Alexei Starovoitov1-0/+13
There are various users of get_vm_area() + ioremap_page_range() APIs. Enforce that get_vm_area() was requested as VM_IOREMAP type and range passed to ioremap_page_range() matches created vm_area to avoid accidentally ioremap-ing into wrong address range. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/bpf/20240305030516.41519-2-alexei.starovoitov@gmail.com
2024-02-24mm: vmalloc: refactor vmalloc_dump_obj() functionUladzislau Rezki (Sony)1-16/+17
This patch tends to simplify the function in question, by removing an extra stack "objp" variable, returning back to an early exit approach if spin_trylock() fails or VA was not found. Link: https://lkml.kernel.org/r/20240124180920.50725-2-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm: vmalloc: improve description of vmap node layerUladzislau Rezki (Sony)1-14/+46
This patch adds extra explanation of recently added vmap node layer based on community feedback. No functional change. Link: https://lkml.kernel.org/r/20240124180920.50725-1-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm: vmalloc: add a shrinker to drain vmap poolsUladzislau Rezki (Sony)1-0/+39
The added shrinker is used to return back current cached VAs into a global vmap space, when a system enters into a low memory mode. Link: https://lkml.kernel.org/r/20240102184633.748113-12-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm: vmalloc: set nr_nodes based on CPUs in a systemUladzislau Rezki (Sony)1-6/+23
A number of nodes which are used in the alloc/free paths is set based on num_possible_cpus() in a system. Please note a high limit threshold though is fixed and corresponds to 128 nodes. For 32-bit or single core systems an access to a global vmap heap is not balanced. Such small systems do not suffer from lock contentions due to low number of CPUs. In such case the nr_nodes is equal to 1. Test on AMD Ryzen Threadripper 3970X 32-Core Processor: sudo ./test_vmalloc.sh run_test_mask=7 nr_threads=64 <default perf> 94.41% 0.89% [kernel] [k] _raw_spin_lock 93.35% 93.07% [kernel] [k] native_queued_spin_lock_slowpath 76.13% 0.28% [kernel] [k] __vmalloc_node_range 72.96% 0.81% [kernel] [k] alloc_vmap_area 56.94% 0.00% [kernel] [k] __get_vm_area_node 41.95% 0.00% [kernel] [k] vmalloc 37.15% 0.01% [test_vmalloc] [k] full_fit_alloc_test 35.17% 0.00% [kernel] [k] ret_from_fork_asm 35.17% 0.00% [kernel] [k] ret_from_fork 35.17% 0.00% [kernel] [k] kthread 35.08% 0.00% [test_vmalloc] [k] test_func 34.45% 0.00% [test_vmalloc] [k] fix_size_alloc_test 28.09% 0.01% [test_vmalloc] [k] long_busy_list_alloc_test 23.53% 0.25% [kernel] [k] vfree.part.0 21.72% 0.00% [kernel] [k] remove_vm_area 20.08% 0.21% [kernel] [k] find_unlink_vmap_area 2.34% 0.61% [kernel] [k] free_vmap_area_noflush <default perf> vs <patch-series perf> 82.32% 0.22% [test_vmalloc] [k] long_busy_list_alloc_test 63.36% 0.02% [kernel] [k] vmalloc 63.34% 2.64% [kernel] [k] __vmalloc_node_range 30.42% 4.46% [kernel] [k] vfree.part.0 28.98% 2.51% [kernel] [k] __alloc_pages_bulk 27.28% 0.19% [kernel] [k] __get_vm_area_node 26.13% 1.50% [kernel] [k] alloc_vmap_area 21.72% 21.67% [kernel] [k] clear_page_rep 19.51% 2.43% [kernel] [k] _raw_spin_lock 16.61% 16.51% [kernel] [k] native_queued_spin_lock_slowpath 13.40% 2.07% [kernel] [k] free_unref_page 10.62% 0.01% [kernel] [k] remove_vm_area 9.02% 8.73% [kernel] [k] insert_vmap_area 8.94% 0.00% [kernel] [k] ret_from_fork_asm 8.94% 0.00% [kernel] [k] ret_from_fork 8.94% 0.00% [kernel] [k] kthread 8.29% 0.00% [test_vmalloc] [k] test_func 7.81% 0.05% [test_vmalloc] [k] full_fit_alloc_test 5.30% 4.73% [kernel] [k] purge_vmap_node 4.47% 2.65% [kernel] [k] free_vmap_area_noflush <patch-series perf> confirms that a native_queued_spin_lock_slowpath goes down to 16.51% percent from 93.07%. The throughput is ~12x higher: urezki@pc638:~$ time sudo ./test_vmalloc.sh run_test_mask=7 nr_threads=64 Run the test with following parameters: run_test_mask=7 nr_threads=64 Done. Check the kernel ring buffer to see the summary. real 10m51.271s user 0m0.013s sys 0m0.187s urezki@pc638:~$ urezki@pc638:~$ time sudo ./test_vmalloc.sh run_test_mask=7 nr_threads=64 Run the test with following parameters: run_test_mask=7 nr_threads=64 Done. Check the kernel ring buffer to see the summary. real 0m51.301s user 0m0.015s sys 0m0.040s urezki@pc638:~$ Link: https://lkml.kernel.org/r/20240102184633.748113-11-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm: vmalloc: support multiple nodes in vmallocinfoUladzislau Rezki (Sony)1-73/+47
Allocated areas are spread among nodes, it implies that the scanning has to be performed individually of each node in order to dump all existing VAs. Link: https://lkml.kernel.org/r/20240102184633.748113-10-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm: vmalloc: support multiple nodes in vread_iterUladzislau Rezki (Sony)1-14/+53
Extend the vread_iter() to be able to perform a sequential reading of VAs which are spread among multiple nodes. So a data read over the /dev/kmem correctly reflects a vmalloc memory layout. Link: https://lkml.kernel.org/r/20240102184633.748113-9-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm: vmalloc: add a scan area of VA only onceUladzislau Rezki (Sony)1-6/+6
Invoke a kmemleak_scan_area() function only for newly allocated objects to add a scan area within that object. There is no reason to add a same scan area(pointer to beginning or inside the object) several times. If a VA is obtained from the cache its scan area has already been associated. Link: https://lkml.kernel.org/r/20240202190628.47806-1-urezki@gmail.com Fixes: 7db166b4aa0d ("mm: vmalloc: offload free_vmap_area_lock lock") Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm: vmalloc: offload free_vmap_area_lock lockUladzislau Rezki (Sony)1-45/+342
Concurrent access to a global vmap space is a bottle-neck. We can simulate a high contention by running a vmalloc test suite. To address it, introduce an effective vmap node logic. Each node behaves as independent entity. When a node is accessed it serves a request directly(if possible) from its pool. This model has a size based pool for requests, i.e. pools are serialized and populated based on object size and real demand. A maximum object size that pool can handle is set to 256 pages. This technique reduces a pressure on the global vmap lock. Link: https://lkml.kernel.org/r/20240102184633.748113-8-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm: vmalloc: remove global purge_vmap_area_root rb-treeUladzislau Rezki (Sony)1-53/+82
Similar to busy VA, lazily-freed area is stored to a node it belongs to. Such approach does not require any global locking primitive, instead an access becomes scalable what mitigates a contention. This patch removes a global purge-lock, global purge-tree and global purge list. Link: https://lkml.kernel.org/r/20240102184633.748113-7-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm/vmalloc: remove vmap_area_listBaoquan He1-2/+0
Earlier, vmap_area_list is exported to vmcoreinfo so that makedumpfile get the base address of vmalloc area. Now, vmap_area_list is empty, so export VMALLOC_START to vmcoreinfo instead, and remove vmap_area_list. [urezki@gmail.com: fix a warning in the crash_save_vmcoreinfo_init()] Link: https://lkml.kernel.org/r/20240111192329.449189-1-urezki@gmail.com Link: https://lkml.kernel.org/r/20240102184633.748113-6-urezki@gmail.com Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Acked-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm: vmalloc: remove global vmap_area_root rb-treeUladzislau Rezki (Sony)1-68/+174
Store allocated objects in a separate nodes. A va->va_start address is converted into a correct node where it should be placed and resided. An addr_to_node() function is used to do a proper address conversion to determine a node that contains a VA. Such approach balances VAs across nodes as a result an access becomes scalable. Number of nodes in a system depends on number of CPUs. Please note: 1. As of now allocated VAs are bound to a node-0. It means the patch does not give any difference comparing with a current behavior; 2. The global vmap_area_lock, vmap_area_root are removed as there is no need in it anymore. The vmap_area_list is still kept and is _empty_. It is exported for a kexec only; 3. The vmallocinfo and vread() have to be reworked to be able to handle multiple nodes. [urezki@gmail.com: mark vmap_init_free_space() with __init tag] Link: https://lkml.kernel.org/r/20240111132628.299644-1-urezki@gmail.com [urezki@gmail.com: fix a wrong value passed to __find_vmap_area()] Link: https://lkml.kernel.org/r/20240111121104.180993-1-urezki@gmail.com Link: https://lkml.kernel.org/r/20240102184633.748113-5-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm: vmalloc: move vmap_init_free_space() down in vmalloc.cUladzislau Rezki (Sony)1-41/+41
A vmap_init_free_space() is a function that setups a vmap space and is considered as part of initialization phase. Since a main entry which is vmalloc_init(), has been moved down in vmalloc.c it makes sense to follow the pattern. There is no a functional change as a result of this patch. Link: https://lkml.kernel.org/r/20240102184633.748113-4-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm: vmalloc: rename adjust_va_to_fit_type() functionUladzislau Rezki (Sony)1-7/+6
This patch renames the adjust_va_to_fit_type() function to va_clip() which is shorter and more expressive. There is no a functional change as a result of this patch. Link: https://lkml.kernel.org/r/20240102184633.748113-3-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm: vmalloc: add va_alloc() helperUladzislau Rezki (Sony)1-13/+28
Patch series "Mitigate a vmap lock contention", v3. 1. Motivation - Offload global vmap locks making it scaled to number of CPUS; - If possible and there is an agreement, we can remove the "Per cpu kva allocator" to make the vmap code to be more simple; - There were complaints from XFS folk that a vmalloc might be contented on their workloads. 2. Design(high level overview) We introduce an effective vmap node logic. A node behaves as independent entity to serve an allocation request directly(if possible) from its pool. That way it bypasses a global vmap space that is protected by its own lock. An access to pools are serialized by CPUs. Number of nodes are equal to number of CPUs in a system. Please note the high threshold is bound to 128 nodes. Pools are size segregated and populated based on system demand. The maximum alloc request that can be stored into a segregated storage is 256 pages. The lazily drain path decays a pool by 25% as a first step and as second populates it by fresh freed VAs for reuse instead of returning them into a global space. When a VA is obtained(alloc path), it is stored in separate nodes. A va->va_start address is converted into a correct node where it should be placed and resided. Doing so we balance VAs across the nodes as a result an access becomes scalable. The addr_to_node() function does a proper address conversion to a correct node. A vmap space is divided on segments with fixed size, it is 16 pages. That way any address can be associated with a segment number. Number of segments are equal to num_possible_cpus() but not grater then 128. The numeration starts from 0. See below how it is converted: static inline unsigned int addr_to_node_id(unsigned long addr) { return (addr / zone_size) % nr_nodes; } On a free path, a VA can be easily found by converting its "va_start" address to a certain node it resides. It is moved from "busy" data to "lazy" data structure. Later on, as noted earlier, the lazy kworker decays each node pool and populates it by fresh incoming VAs. Please note, a VA is returned to a node that did an alloc request. 3. Test on AMD Ryzen Threadripper 3970X 32-Core Processor sudo ./test_vmalloc.sh run_test_mask=7 nr_threads=64 <default perf> 94.41% 0.89% [kernel] [k] _raw_spin_lock 93.35% 93.07% [kernel] [k] native_queued_spin_lock_slowpath 76.13% 0.28% [kernel] [k] __vmalloc_node_range 72.96% 0.81% [kernel] [k] alloc_vmap_area 56.94% 0.00% [kernel] [k] __get_vm_area_node 41.95% 0.00% [kernel] [k] vmalloc 37.15% 0.01% [test_vmalloc] [k] full_fit_alloc_test 35.17% 0.00% [kernel] [k] ret_from_fork_asm 35.17% 0.00% [kernel] [k] ret_from_fork 35.17% 0.00% [kernel] [k] kthread 35.08% 0.00% [test_vmalloc] [k] test_func 34.45% 0.00% [test_vmalloc] [k] fix_size_alloc_test 28.09% 0.01% [test_vmalloc] [k] long_busy_list_alloc_test 23.53% 0.25% [kernel] [k] vfree.part.0 21.72% 0.00% [kernel] [k] remove_vm_area 20.08% 0.21% [kernel] [k] find_unlink_vmap_area 2.34% 0.61% [kernel] [k] free_vmap_area_noflush <default perf> vs <patch-series perf> 82.32% 0.22% [test_vmalloc] [k] long_busy_list_alloc_test 63.36% 0.02% [kernel] [k] vmalloc 63.34% 2.64% [kernel] [k] __vmalloc_node_range 30.42% 4.46% [kernel] [k] vfree.part.0 28.98% 2.51% [kernel] [k] __alloc_pages_bulk 27.28% 0.19% [kernel] [k] __get_vm_area_node 26.13% 1.50% [kernel] [k] alloc_vmap_area 21.72% 21.67% [kernel] [k] clear_page_rep 19.51% 2.43% [kernel] [k] _raw_spin_lock 16.61% 16.51% [kernel] [k] native_queued_spin_lock_slowpath 13.40% 2.07% [kernel] [k] free_unref_page 10.62% 0.01% [kernel] [k] remove_vm_area 9.02% 8.73% [kernel] [k] insert_vmap_area 8.94% 0.00% [kernel] [k] ret_from_fork_asm 8.94% 0.00% [kernel] [k] ret_from_fork 8.94% 0.00% [kernel] [k] kthread 8.29% 0.00% [test_vmalloc] [k] test_func 7.81% 0.05% [test_vmalloc] [k] full_fit_alloc_test 5.30% 4.73% [kernel] [k] purge_vmap_node 4.47% 2.65% [kernel] [k] free_vmap_area_noflush <patch-series perf> confirms that a native_queued_spin_lock_slowpath goes down to 16.51% percent from 93.07%. The throughput is ~12x higher: urezki@pc638:~$ time sudo ./test_vmalloc.sh run_test_mask=7 nr_threads=64 Run the test with following parameters: run_test_mask=7 nr_threads=64 Done. Check the kernel ring buffer to see the summary. real 10m51.271s user 0m0.013s sys 0m0.187s urezki@pc638:~$ urezki@pc638:~$ time sudo ./test_vmalloc.sh run_test_mask=7 nr_threads=64 Run the test with following parameters: run_test_mask=7 nr_threads=64 Done. Check the kernel ring buffer to see the summary. real 0m51.301s user 0m0.015s sys 0m0.040s urezki@pc638:~$ This patch (of 11): Currently __alloc_vmap_area() function contains an open codded logic that finds and adjusts a VA based on allocation request. Introduce a va_alloc() helper that adjusts found VA only. There is no a functional change as a result of this patch. Link: https://lkml.kernel.org/r/20240102184633.748113-1-urezki@gmail.com Link: https://lkml.kernel.org/r/20240102184633.748113-2-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-11-01mm/vmalloc: fix the unchecked dereference warning in vread_iter()Baoquan He1-1/+1
LKP reported smatch warning as below: =================== smatch warnings: mm/vmalloc.c:3689 vread_iter() error: we previously assumed 'vm' could be null (see line 3667) ...... 06c8994626d1b7 @3667 size = vm ? get_vm_area_size(vm) : va_size(va); ...... 06c8994626d1b7 @3689 else if (!(vm->flags & VM_IOREMAP)) ^^^^^^^^^ Unchecked dereference ===================== This is not a runtime bug because the possible null 'vm' in the pointed place could only happen when flags == VMAP_BLOCK. However, the case 'flags == VMAP_BLOCK' should never happen and has been detected with WARN_ON. Please check vm_map_ram() implementation and the earlier checking in vread_iter() at below: ~~~~~~~~~~~~~~~~~~~~~~~~~~ /* * VMAP_BLOCK indicates a sub-type of vm_map_ram area, need * be set together with VMAP_RAM. */ WARN_ON(flags == VMAP_BLOCK); if (!vm && !flags) continue; ~~~~~~~~~~~~~~~~~~~~~~~~~~ So add checking on whether 'vm' could be null when dereferencing it in vread_iter(). This mutes smatch complaint. Link: https://lkml.kernel.org/r/ZTCURc8ZQE+KrTvS@MiWiFi-R3L-srv Link: https://lkml.kernel.org/r/ZS/2k6DIMd0tZRgK@MiWiFi-R3L-srv Signed-off-by: Baoquan He <bhe@redhat.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/r/202310171600.WCrsOwFj-lkp@intel.com/ Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Philip Li <philip.li@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-30mm: hugetlb: add huge page size param to set_huge_pte_at()Ryan Roberts1-1/+1
Patch series "Fix set_huge_pte_at() panic on arm64", v2. This series fixes a bug in arm64's implementation of set_huge_pte_at(), which can result in an unprivileged user causing a kernel panic. The problem was triggered when running the new uffd poison mm selftest for HUGETLB memory. This test (and the uffd poison feature) was merged for v6.5-rc7. Ideally, I'd like to get this fix in for v6.6 and I've cc'ed stable (correctly this time) to get it backported to v6.5, where the issue first showed up. Description of Bug ================== arm64's huge pte implementation supports multiple huge page sizes, some of which are implemented in the page table with multiple contiguous entries. So set_huge_pte_at() needs to work out how big the logical pte is, so that it can also work out how many physical ptes (or pmds) need to be written. It previously did this by grabbing the folio out of the pte and querying its size. However, there are cases when the pte being set is actually a swap entry. But this also used to work fine, because for huge ptes, we only ever saw migration entries and hwpoison entries. And both of these types of swap entries have a PFN embedded, so the code would grab that and everything still worked out. But over time, more calls to set_huge_pte_at() have been added that set swap entry types that do not embed a PFN. And this causes the code to go bang. The triggering case is for the uffd poison test, commit 99aa77215ad0 ("selftests/mm: add uffd unit test for UFFDIO_POISON"), which causes a PTE_MARKER_POISONED swap entry to be set, coutesey of commit 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs") - added in v6.5-rc7. Although review shows that there are other call sites that set PTE_MARKER_UFFD_WP (which also has no PFN), these don't trigger on arm64 because arm64 doesn't support UFFD WP. If CONFIG_DEBUG_VM is enabled, we do at least get a BUG(), but otherwise, it will dereference a bad pointer in page_folio(): static inline struct folio *hugetlb_swap_entry_to_folio(swp_entry_t entry) { VM_BUG_ON(!is_migration_entry(entry) && !is_hwpoison_entry(entry)); return page_folio(pfn_to_page(swp_offset_pfn(entry))); } Fix === The simplest fix would have been to revert the dodgy cleanup commit 18f3962953e4 ("mm: hugetlb: kill set_huge_swap_pte_at()"), but since things have moved on, this would have required an audit of all the new set_huge_pte_at() call sites to see if they should be converted to set_huge_swap_pte_at(). As per the original intent of the change, it would also leave us open to future bugs when people invariably get it wrong and call the wrong helper. So instead, I've added a huge page size parameter to set_huge_pte_at(). This means that the arm64 code has the size in all cases. It's a bigger change, due to needing to touch the arches that implement the function, but it is entirely mechanical, so in my view, low risk. I've compile-tested all touched arches; arm64, parisc, powerpc, riscv, s390, sparc (and additionally x86_64). I've additionally booted and run mm selftests against arm64, where I observe the uffd poison test is fixed, and there are no other regressions. This patch (of 2): In order to fix a bug, arm64 needs to be told the size of the huge page for which the pte is being set in set_huge_pte_at(). Provide for this by adding an `unsigned long sz` parameter to the function. This follows the same pattern as huge_pte_clear(). This commit makes the required interface modifications to the core mm as well as all arches that implement this function (arm64, parisc, powerpc, riscv, s390, sparc). The actual arm64 bug will be fixed in a separate commit. No behavioral changes intended. Link: https://lkml.kernel.org/r/20230922115804.2043771-1-ryan.roberts@arm.com Link: https://lkml.kernel.org/r/20230922115804.2043771-2-ryan.roberts@arm.com Fixes: 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs") Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> [powerpc 8xx] Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> [vmalloc change] Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: <stable@vger.kernel.org> [6.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-05mm/vmalloc: add a safer version of find_vm_area() for debugJoel Fernandes (Google)1-4/+22
It is unsafe to dump vmalloc area information when trying to do so from some contexts. Add a safer trylock version of the same function to do a best-effort VMA finding and use it from vmalloc_dump_obj(). [applied test robot feedback on unused function fix.] [applied Uladzislau feedback on locking.] Link: https://lkml.kernel.org/r/20230904180806.1002832-1-joel@joelfernandes.org Fixes: 98f180837a89 ("mm: Make mem_dump_obj() handle vmalloc() memory") Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reported-by: Zhen Lei <thunder.leizhen@huaweicloud.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Zqiang <qiang.zhang1211@gmail.com> Cc: <stable@vger.kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm: add a call to flush_cache_vmap() in vmap_pfn()Alexandre Ghiti1-0/+4
flush_cache_vmap() must be called after new vmalloc mappings are installed in the page table in order to allow architectures to make sure the new mapping is visible. It could lead to a panic since on some architectures (like powerpc), the page table walker could see the wrong pte value and trigger a spurious page fault that can not be resolved (see commit f1cb8f9beba8 ("powerpc/64s/radix: avoid ptesync after set_pte and ptep_set_access_flags")). But actually the patch is aiming at riscv: the riscv specification allows the caching of invalid entries in the TLB, and since we recently removed the vmalloc page fault handling, we now need to emit a tlb shootdown whenever a new vmalloc mapping is emitted (https://lore.kernel.org/linux-riscv/20230725132246.817726-1-alexghiti@rivosinc.com/). That's a temporary solution, there are ways to avoid that :) Link: https://lkml.kernel.org/r/20230809164633.1556126-1-alexghiti@rivosinc.com Fixes: 3e9a9e256b1e ("mm: add a vmap_pfn function") Reported-by: Dylan Jhong <dylan@andestech.com> Closes: https://lore.kernel.org/linux-riscv/ZMytNY2J8iyjbPPy@atctrx.andestech.com/ Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Dylan Jhong <dylan@andestech.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-24Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes.Andrew Morton1-4/+13
2023-06-20mm: ptep_get() conversionRyan Roberts1-3/+3
Convert all instances of direct pte_t* dereferencing to instead use ptep_get() helper. This means that by default, the accesses change from a C dereference to a READ_ONCE(). This is technically the correct thing to do since where pgtables are modified by HW (for access/dirty) they are volatile and therefore we should always ensure READ_ONCE() semantics. But more importantly, by always using the helper, it can be overridden by the architecture to fully encapsulate the contents of the pte. Arch code is deliberately not converted, as the arch code knows best. It is intended that arch code (arm64) will override the default with its own implementation that can (e.g.) hide certain bits from the core code, or determine young/dirty status by mixing in state from another source. Conversion was done using Coccinelle: ---- // $ make coccicheck \ // COCCI=ptepget.cocci \ // SPFLAGS="--include-headers" \ // MODE=patch virtual patch @ depends on patch @ pte_t *v; @@ - *v + ptep_get(v) ---- Then reviewed and hand-edited to avoid multiple unnecessary calls to ptep_get(), instead opting to store the result of a single call in a variable, where it is correct to do so. This aims to negate any cost of READ_ONCE() and will benefit arch-overrides that may be more complex. Included is a fix for an issue in an earlier version of this patch that was pointed out by kernel test robot. The issue arose because config MMU=n elides definition of the ptep helper functions, including ptep_get(). HUGETLB_PAGE=n configs still define a simple huge_ptep_clear_flush() for linking purposes, which dereferences the ptep. So when both configs are disabled, this caused a build error because ptep_get() is not defined. Fix by continuing to do a direct dereference when MMU=n. This is safe because for this config the arch code cannot be trying to virtualize the ptes because none of the ptep helpers are defined. Link: https://lkml.kernel.org/r/20230612151545.3317766-4-ryan.roberts@arm.com Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202305120142.yXsNEo6H-lkp@intel.com/ Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dave Airlie <airlied@gmail.com> Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: SeongJae Park <sj@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-20mm/vmalloc: vmalloc_to_page() use pte_offset_kernel()Hugh Dickins1-2/+1
vmalloc_to_page() was using pte_offset_map() (followed by pte_unmap()), but it's intended for userspace page tables: prefer pte_offset_kernel(). Link: https://lkml.kernel.org/r/696386a-84f8-b33c-82e5-f865ed6eb39@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-20mm/vmalloc: replace the ternary conditional operator with min()Lu Hongfei1-1/+1
It would be better to replace the traditional ternary conditional operator with min() in zero_iter Link: https://lkml.kernel.org/r/20230609093057.27777-1-luhongfei@vivo.com Signed-off-by: Lu Hongfei <luhongfei@vivo.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19mm/vmalloc: do not output a spurious warning when huge vmalloc() failsLorenzo Stoakes1-4/+13
In __vmalloc_area_node() we always warn_alloc() when an allocation performed by vm_area_alloc_pages() fails unless it was due to a pending fatal signal. However, huge page allocations instigated either by vmalloc_huge() or __vmalloc_node_range() (or a caller that invokes this like kvmalloc() or kvmalloc_node()) always falls back to order-0 allocations if the huge page allocation fails. This renders the warning useless and noisy, especially as all callers appear to be aware that this may fallback. This has already resulted in at least one bug report from a user who was confused by this (see link). Therefore, simply update the code to only output this warning for order-0 pages when no fatal signal is pending. Link: https://bugzilla.suse.com/show_bug.cgi?id=1211410 Link: https://lkml.kernel.org/r/20230605201107.83298-1-lstoakes@gmail.com Fixes: 80b1d8fdfad1 ("mm: vmalloc: correct use of __GFP_NOWARN mask in __vmalloc_area_node()") Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm: vmalloc must set pte via arch codeRyan Roberts1-2/+8
Patch series "Fixes for pte encapsulation bypasses", v3. A series to improve the encapsulation of pte entries by disallowing non-arch code from directly dereferencing pte_t pointers. This patch (of 4): It is bad practice to directly set pte entries within a pte table. Instead all modifications must go through arch-provided helpers such as set_pte_at() to give the arch code visibility and allow it to check (and potentially modify) the operation. Link: https://lkml.kernel.org/r/20230602092949.545577-1-ryan.roberts@arm.com Link: https://lkml.kernel.org/r/20230602092949.545577-2-ryan.roberts@arm.com Fixes: 3e9a9e256b1e ("mm: add a vmap_pfn function") Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: SeongJae Park <sj@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm/vmalloc: dont purge usable blocks unnecessarilyThomas Gleixner1-8/+20
Purging fragmented blocks is done unconditionally in several contexts: 1) From drain_vmap_area_work(), when the number of lazy to be freed vmap_areas reached the threshold 2) Reclaiming vmalloc address space from pcpu_get_vm_areas() 3) _vm_unmap_aliases() #1 There is no reason to zap fragmented vmap blocks unconditionally, simply because reclaiming all lazy areas drains at least 32MB * fls(num_online_cpus()) per invocation which is plenty. #2 Reclaiming when running out of space or due to memory pressure makes a lot of sense #3 _unmap_aliases() requires to touch everything because the caller has no clue which vmap_area used a particular page last and the vmap_area lost that information too. Except for the vfree + VM_FLUSH_RESET_PERMS case, which removes the vmap area first and then cares about the flush. That in turn requires a full walk of _all_ vmap areas including the one which was just added to the purge list. But as this has to be flushed anyway this is an opportunity to combine outstanding TLB flushes and do the housekeeping of purging freed areas, but like #1 there is no real good reason to zap usable vmap blocks unconditionally. Add a @force_purge argument to the newly split out block purge function and if not true only purge fragmented blocks which have less than 1/4 of their capacity left. Rename purge_vmap_area_lazy() to reclaim_and_purge_vmap_areas() to make it clear what the function does. [lstoakes@gmail.com: correct VMAP_PURGE_THRESHOLD check] Link: https://lkml.kernel.org/r/3e92ef61-b910-4576-88e7-cf43211fd4e7@lucifer.local Link: https://lkml.kernel.org/r/20230525124504.864005691@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm/vmalloc: add missing READ/WRITE_ONCE() annotationsThomas Gleixner1-5/+8
purge_fragmented_blocks() accesses vmap_block::free and vmap_block::dirty lockless for a quick check. Add the missing READ/WRITE_ONCE() annotations. Link: https://lkml.kernel.org/r/20230525124504.807356682@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm/vmalloc: check free space in vmap_block locklessThomas Gleixner1-1/+4
vb_alloc() unconditionally locks a vmap_block on the free list to check the free space. This can be done locklessly because vmap_block::free never increases, it's only decreased on allocations. Check the free space lockless and only if that succeeds, recheck under the lock. Link: https://lkml.kernel.org/r/20230525124504.750481992@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm/vmalloc: prevent flushing dirty space over and overThomas Gleixner1-2/+6
vmap blocks which have active mappings cannot be purged. Allocations which have been freed are accounted for in vmap_block::dirty_min/max, so that they can be detected in _vm_unmap_aliases() as potentially stale TLBs. If there are several invocations of _vm_unmap_aliases() then each of them will flush the dirty range. That's pointless and just increases the probability of full TLB flushes. Avoid that by resetting the flush range after accounting for it. That's safe versus other invocations of _vm_unmap_aliases() because this is all serialized with vmap_purge_lock. Link: https://lkml.kernel.org/r/20230525124504.692056496@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm/vmalloc: avoid iterating over per CPU vmap blocks twiceThomas Gleixner1-24/+46
_vunmap_aliases() walks the per CPU xarrays to find partially unmapped blocks and then walks the per cpu free lists to purge fragmented blocks. Arguably that's waste of CPU cycles and cache lines as the full xarray walk already touches every block. Avoid this double iteration: - Split out the code to purge one block and the code to free the local purge list into helper functions. - Try to purge the fragmented blocks in the xarray walk before looking at their dirty space. Link: https://lkml.kernel.org/r/20230525124504.633469722@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10mm/vmalloc: prevent stale TLBs in fully utilized blocksThomas Gleixner1-1/+2
Patch series "mm/vmalloc: Assorted fixes and improvements", v2. this series addresses the following issues: 1) Prevent the stale TLB problem related to fully utilized vmap blocks 2) Avoid the double per CPU list walk in _vm_unmap_aliases() 3) Avoid flushing dirty space over and over 4) Add a lockless quickcheck in vb_alloc() and add missing READ/WRITE_ONCE() annotations 5) Prevent overeager purging of usable vmap_blocks if not under memory/address space pressure. This patch (of 6): _vm_unmap_aliases() is used to ensure that no unflushed TLB entries for a page are left in the system. This is required due to the lazy TLB flush mechanism in vmalloc. This is tried to achieve by walking the per CPU free lists, but those do not contain fully utilized vmap blocks because they are removed from the free list once the blocks free space became zero. When the block is not fully unmapped then it is not on the purge list either. So neither the per CPU list iteration nor the purge list walk find the block and if the page was mapped via such a block and the TLB has not yet been flushed, the guarantee of _vm_unmap_aliases() that there are no stale TLBs after returning is broken: x = vb_alloc() // Removes vmap_block from free list because vb->free became 0 vb_free(x) // Unmaps page and marks in dirty_min/max range // Block has still mappings and is not put on purge list // Page is reused vm_unmap_aliases() // Can't find vmap block with the dirty space -> FAIL So instead of walking the per CPU free lists, walk the per CPU xarrays which hold pointers to _all_ active blocks in the system including those removed from the free lists. Link: https://lkml.kernel.org/r/20230525122342.109672430@linutronix.de Link: https://lkml.kernel.org/r/20230525124504.573987880@linutronix.de Fixes: db64fe02258f ("mm: rewrite vmap layer") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-19mm: vmalloc: rename addr_to_vb_xarray() functionUladzislau Rezki (Sony)1-6/+6
Short the name of the addr_to_vb_xarray() function to the addr_to_vb_xa(). This aligns with other internal function abbreviations. Link: https://lkml.kernel.org/r/20230331073727.6968-1-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Suggested-by: Baoquan He <bhe@redhat.com> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-19mm: vmalloc: remove a global vmap_blocks xarrayUladzislau Rezki (Sony)1-8/+63
A global vmap_blocks-xarray array can be contented under heavy usage of the vm_map_ram()/vm_unmap_ram() APIs. The lock_stat shows that a "vmap_blocks.xa_lock" lock is a second in a top-list when it comes to contentions: <snip> ---------------------------------------- class name con-bounces contentions ... ---------------------------------------- vmap_area_lock: 2554079 2554276 ... -------------- vmap_area_lock 1297948 [<00000000dd41cbaa>] alloc_vmap_area+0x1c7/0x910 vmap_area_lock 1256330 [<000000009d927bf3>] free_vmap_block+0x4a/0xe0 vmap_area_lock 1 [<00000000c95c05a7>] find_vm_area+0x16/0x70 -------------- vmap_area_lock 1738590 [<00000000dd41cbaa>] alloc_vmap_area+0x1c7/0x910 vmap_area_lock 815688 [<000000009d927bf3>] free_vmap_block+0x4a/0xe0 vmap_area_lock 1 [<00000000c1d619d7>] __get_vm_area_node+0xd2/0x170 vmap_blocks.xa_lock: 862689 862698 ... ------------------- vmap_blocks.xa_lock 378418 [<00000000625a5626>] vm_map_ram+0x359/0x4a0 vmap_blocks.xa_lock 484280 [<00000000caa2ef03>] xa_erase+0xe/0x30 ------------------- vmap_blocks.xa_lock 576226 [<00000000caa2ef03>] xa_erase+0xe/0x30 vmap_blocks.xa_lock 286472 [<00000000625a5626>] vm_map_ram+0x359/0x4a0 ... <snip> that is a result of running vm_map_ram()/vm_unmap_ram() in a loop. The test creates 64(on 64 CPUs system) threads and each one maps/unmaps 1 page. After this change the "xa_lock" can be considered as a noise in the same test condition: <snip> ... &xa->xa_lock#1: 10333 10394 ... -------------- &xa->xa_lock#1 5349 [<00000000bbbc9751>] xa_erase+0xe/0x30 &xa->xa_lock#1 5045 [<0000000018def45d>] vm_map_ram+0x3a4/0x4f0 -------------- &xa->xa_lock#1 7326 [<0000000018def45d>] vm_map_ram+0x3a4/0x4f0 &xa->xa_lock#1 3068 [<00000000bbbc9751>] xa_erase+0xe/0x30 ... <snip> Running the test_vmalloc.sh run_test_mask=1024 nr_threads=64 nr_pages=5 shows around ~8 percent of throughput improvement of vm_map_ram() and vm_unmap_ram() APIs. This patch does not fix vmap_area_lock/free_vmap_area_lock and purge_vmap_area_lock bottle-necks, it is rather a separate rework. Link: https://lkml.kernel.org/r/20230330190639.431589-1-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-19sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changesAndrew Morton1-3/+7
2023-04-19mm: kmsan: handle alloc failures in kmsan_ioremap_page_range()Alexander Potapenko1-2/+2
Similarly to kmsan_vmap_pages_range_noflush(), kmsan_ioremap_page_range() must also properly handle allocation/mapping failures. In the case of such, it must clean up the already created metadata mappings and return an error code, so that the error can be propagated to ioremap_page_range(). Without doing so, KMSAN may silently fail to bring the metadata for the page range into a consistent state, which will result in user-visible crashes when trying to access them. Link: https://lkml.kernel.org/r/20230413131223.4135168-2-glider@google.com Fixes: b073d7f8aee4 ("mm: kmsan: maintain KMSAN metadata for page operations") Signed-off-by: Alexander Potapenko <glider@google.com> Reported-by: Dipanjan Das <mail.dipanjan.das@gmail.com> Link: https://lore.kernel.org/linux-mm/CANX2M5ZRrRA64k0hOif02TjmY9kbbO2aCBPyq79es34RXZ=cAw@mail.gmail.com/ Reviewed-by: Marco Elver <elver@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-19mm: kmsan: handle alloc failures in kmsan_vmap_pages_range_noflush()Alexander Potapenko1-1/+5
As reported by Dipanjan Das, when KMSAN is used together with kernel fault injection (or, generally, even without the latter), calls to kcalloc() or __vmap_pages_range_noflush() may fail, leaving the metadata mappings for the virtual mapping in an inconsistent state. When these metadata mappings are accessed later, the kernel crashes. To address the problem, we return a non-zero error code from kmsan_vmap_pages_range_noflush() in the case of any allocation/mapping failure inside it, and make vmap_pages_range_noflush() return an error if KMSAN fails to allocate the metadata. This patch also removes KMSAN_WARN_ON() from vmap_pages_range_noflush(), as these allocation failures are not fatal anymore. Link: https://lkml.kernel.org/r/20230413131223.4135168-1-glider@google.com Fixes: b073d7f8aee4 ("mm: kmsan: maintain KMSAN metadata for page operations") Signed-off-by: Alexander Potapenko <glider@google.com> Reported-by: Dipanjan Das <mail.dipanjan.das@gmail.com> Link: https://lore.kernel.org/linux-mm/CANX2M5ZRrRA64k0hOif02TjmY9kbbO2aCBPyq79es34RXZ=cAw@mail.gmail.com/ Reviewed-by: Marco Elver <elver@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-16sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changesAndrew Morton1-3/+5
2023-04-06mm: vmalloc: convert vread() to vread_iter()Lorenzo Stoakes1-88/+147
Having previously laid the foundation for converting vread() to an iterator function, pull the trigger and do so. This patch attempts to provide minimal refactoring and to reflect the existing logic as best we can, for example we continue to zero portions of memory not read, as before. Overall, there should be no functional difference other than a performance improvement in /proc/kcore access to vmalloc regions. Now we have eliminated the need for a bounce buffer in read_kcore_iter(), we dispense with it, and try to write to user memory optimistically but with faults disabled via copy_page_to_iter_nofault(). We already have preemption disabled by holding a spin lock. We continue faulting in until the operation is complete. Additionally, we must account for the fact that at any point a copy may fail (most likely due to a fault not being able to occur), we exit indicating fewer bytes retrieved than expected. [sfr@canb.auug.org.au: fix sparc64 warning] Link: https://lkml.kernel.org/r/20230320144721.663280c3@canb.auug.org.au [lstoakes@gmail.com: redo Stephen's sparc build fix] Link: https://lkml.kernel.org/r/8506cbc667c39205e65a323f750ff9c11a463798.1679566220.git.lstoakes@gmail.com [akpm@linux-foundation.org: unbreak uio.h includes] Link: https://lkml.kernel.org/r/941f88bc5ab928e6656e1e2593b91bf0f8c81e1b.1679511146.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>