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2023-10-04Docs/mm/damon/design: explicitly introduce ``nr_accesses``SeongJae Park1-3/+4
The design document is explaining about the access tracking mechanism and the access rate counter (nr_accesses), but not directly mentions the name. Add a sentence for making it clear. Link: https://lkml.kernel.org/r/20230907022929.91361-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04Docs/admin-guide/mm/damon/usage: move debugfs intro to the bottom of the sectionSeongJae Park1-6/+6
On the DAMON usage introduction section, the introduction of DAMON debugfs interface, which is deprecated, is above kernel API, which is actively supported. Move the DAMON debugfs intro to bottom, so that readers have less chances to read it. Link: https://lkml.kernel.org/r/20230907022929.91361-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04Docs/admin-guide/mm/damon/usage: place debugfs usage at the bottomSeongJae Park1-20/+19
debugfs interface is deprecated. Put it at the bottom of the document so that readers have less chances to read it. Link: https://lkml.kernel.org/r/20230907022929.91361-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04Docs/admin-guide/mm/damon/usage: fixup missed :ref: keywordSeongJae Park1-1/+1
Patch series "mm/damon: misc fixups for documents, comments and its tracepoint". This patchset contains miscellaneous simple fixups for documents, comments and tracepoint of DAMON. This patch (of 11): A cross-link reference in DAMON usage document is missing ':ref:' Sphynx keyword. Fix it. Link: https://lkml.kernel.org/r/20230907022929.91361-1-sj@kernel.org Link: https://lkml.kernel.org/r/20230907022929.91361-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04zswap: change zswap's default allocator to zsmallocNhat Pham1-0/+1
Out of zswap's 3 allocators, zsmalloc is the clear superior in terms of memory utilization, both in theory and as observed in practice, with its high storage density and low internal fragmentation. zsmalloc is also more actively developed and maintained, since it is the allocator of choice for zswap for many users, as well as the only allocator for zram. A historical objection to the selection of zsmalloc as the default allocator for zswap is its lack of writeback capability. However, this has changed, with the zsmalloc writeback patchset, and the subsequent zswap LRU refactor. With this, there is not a lot of good reasons to keep zbud, an otherwise inferior allocator, as the default instead of zswap. This patch changes the default allocator to zsmalloc. The only exception is on settings without MMU, in which case zbud will remain as the default. Link: https://lkml.kernel.org/r/20230908235115.2943486-1-nphamcs@gmail.com Signed-off-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Yosry Ahmed <yosryahmed@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04selftests: mm: add a test for moving from an offset from start of mappingJoel Fernandes1-55/+134
It is possible that the aligned address falls on no existing mapping, however that does not mean that we can just align it down to that. This test verifies that the "vma->vm_start != addr_to_align" check in can_align_down() prevents disastrous results if aligning down when source and dest are mutually aligned within a PMD but the source/dest addresses requested are not at the beginning of the respective mapping containing these addresses. Link: https://lkml.kernel.org/r/20230903151328.2981432-8-joel@joelfernandes.org Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04selftests: mm: add a test for remapping within a rangeJoel Fernandes (Google)1-1/+78
Move a block of memory within a memory range. Any alignment optimization on the source address may cause corruption. Verify using kselftest that it works. I have also verified with tracing that such optimization does not happen due to this check in can_align_down(): if (!for_stack && vma->vm_start != addr_to_align) return false; Link: https://lkml.kernel.org/r/20230903151328.2981432-7-joel@joelfernandes.org Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04selftests: mm: add a test for remapping to area immediately after existing ↵Joel Fernandes (Google)1-5/+52
mapping This patch adds support for verifying that we correctly handle the situation where something is already mapped before the destination of the remap. Any realignment of destination address and PMD-copy will destroy that existing mapping. In such cases, we need to avoid doing the optimization. To test this, we map an area called the preamble before the remap region. Then we verify after the mremap operation that this region did not get corrupted. Putting some prints in the kernel, I verified that we optimize correctly in different situations: Optimize when there is alignment and no previous mapping (this is tested by previous patch). <prints> can_align_down(old_vma->vm_start=2900000, old_addr=2900000, mask=-2097152): 0 can_align_down(new_vma->vm_start=2f00000, new_addr=2f00000, mask=-2097152): 0 === Starting move_page_tables === Doing PUD move for 2800000 -> 2e00000 of extent=200000 <-- Optimization Doing PUD move for 2a00000 -> 3000000 of extent=200000 Doing PUD move for 2c00000 -> 3200000 of extent=200000 </prints> Don't optimize when there is alignment but there is previous mapping (this is tested by this patch). Notice that can_align_down() returns 1 for the destination mapping as we detected there is something there. <prints> can_align_down(old_vma->vm_start=2900000, old_addr=2900000, mask=-2097152): 0 can_align_down(new_vma->vm_start=5700000, new_addr=5700000, mask=-2097152): 1 === Starting move_page_tables === Doing move_ptes for 2900000 -> 5700000 of extent=100000 <-- Unoptimized Doing PUD move for 2a00000 -> 5800000 of extent=200000 Doing PUD move for 2c00000 -> 5a00000 of extent=200000 </prints> Link: https://lkml.kernel.org/r/20230903151328.2981432-6-joel@joelfernandes.org Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04selftests: mm: add a test for mutually aligned moves > PMD sizeJoel Fernandes (Google)1-1/+11
This patch adds a test case to check if a PMD-alignment optimization successfully happens. I add support to make sure there is some room before the source mapping, otherwise the optimization to trigger PMD-aligned move will be disabled as the kernel will detect that a mapping before the source exists and such optimization becomes impossible. Link: https://lkml.kernel.org/r/20230903151328.2981432-5-joel@joelfernandes.org Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04selftests: mm: fix failure case when new remap region was not foundJoel Fernandes (Google)1-1/+1
When a valid remap region could not be found, the source mapping is not cleaned up. Fix the goto statement such that the clean up happens. Link: https://lkml.kernel.org/r/20230903151328.2981432-4-joel@joelfernandes.org Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/mremap: allow moves within the same VMA for stack movesJoel Fernandes (Google)3-16/+21
For the stack move happening in shift_arg_pages(), the move is happening within the same VMA which spans the old and new ranges. In case the aligned address happens to fall within that VMA, allow such moves and don't abort the mremap alignment optimization. In the regular non-stack mremap case, we cannot allow any such moves as will end up destroying some part of the mapping (either the source of the move, or part of the existing mapping). So just avoid it for stack moves. Link: https://lkml.kernel.org/r/20230903151328.2981432-3-joel@joelfernandes.org Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/mremap: optimize the start addresses in move_page_tables()Joel Fernandes (Google)1-0/+62
Patch series "Optimize mremap during mutual alignment within PMD", v6. This patchset optimizes the start addresses in move_page_tables() and tests the changes. It addresses a warning [1] that occurs due to a downward, overlapping move on a mutually-aligned offset within a PMD during exec. By initiating the copy process at the PMD level when such alignment is present, we can prevent this warning and speed up the copying process at the same time. Linus Torvalds suggested this idea. Check the individual patches for more details. [1] https://lore.kernel.org/all/ZB2GTBD%2FLWTrkOiO@dhcp22.suse.cz/ This patch (of 7): Recently, we see reports [1] of a warning that triggers due to move_page_tables() doing a downward and overlapping move on a mutually-aligned offset within a PMD. By mutual alignment, I mean the source and destination addresses of the mremap are at the same offset within a PMD. This mutual alignment along with the fact that the move is downward is sufficient to cause a warning related to having an allocated PMD that does not have PTEs in it. This warning will only trigger when there is mutual alignment in the move operation. A solution, as suggested by Linus Torvalds [2], is to initiate the copy process at the PMD level whenever such alignment is present. Implementing this approach will not only prevent the warning from being triggered, but it will also optimize the operation as this method should enhance the speed of the copy process whenever there's a possibility to start copying at the PMD level. Some more points: a. The optimization can be done only when both the source and destination of the mremap do not have anything mapped below it up to a PMD boundary. I add support to detect that. b. #1 is not a problem for the call to move_page_tables() from exec.c as nothing is expected to be mapped below the source. However, for non-overlapping mutually aligned moves as triggered by mremap(2), I added support for checking such cases. c. I currently only optimize for PMD moves, in the future I/we can build on this work and do PUD moves as well if there is a need for this. But I want to take it one step at a time. d. We need to be careful about mremap of ranges within the VMA itself. For this purpose, I added checks to determine if the address after alignment falls within its VMA itself. [1] https://lore.kernel.org/all/ZB2GTBD%2FLWTrkOiO@dhcp22.suse.cz/ [2] https://lore.kernel.org/all/CAHk-=whd7msp8reJPfeGNyt0LiySMT0egExx3TVZSX3Ok6X=9g@mail.gmail.com/ Link: https://lkml.kernel.org/r/20230903151328.2981432-1-joel@joelfernandes.org Link: https://lkml.kernel.org/r/20230903151328.2981432-2-joel@joelfernandes.org Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm: hugetlb_vmemmap: fix hugetlb page number decrease failed on movable nodesYuan Can1-1/+1
The decreasing of hugetlb pages number failed with the following message given: sh: page allocation failure: order:0, mode:0x204cc0(GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_THISNODE) CPU: 1 PID: 112 Comm: sh Not tainted 6.5.0-rc7-... #45 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace.part.6+0x84/0xe4 show_stack+0x18/0x24 dump_stack_lvl+0x48/0x60 dump_stack+0x18/0x24 warn_alloc+0x100/0x1bc __alloc_pages_slowpath.constprop.107+0xa40/0xad8 __alloc_pages+0x244/0x2d0 hugetlb_vmemmap_restore+0x104/0x1e4 __update_and_free_hugetlb_folio+0x44/0x1f4 update_and_free_hugetlb_folio+0x20/0x68 update_and_free_pages_bulk+0x4c/0xac set_max_huge_pages+0x198/0x334 nr_hugepages_store_common+0x118/0x178 nr_hugepages_store+0x18/0x24 kobj_attr_store+0x18/0x2c sysfs_kf_write+0x40/0x54 kernfs_fop_write_iter+0x164/0x1dc vfs_write+0x3a8/0x460 ksys_write+0x6c/0x100 __arm64_sys_write+0x1c/0x28 invoke_syscall+0x44/0x100 el0_svc_common.constprop.1+0x6c/0xe4 do_el0_svc+0x38/0x94 el0_svc+0x28/0x74 el0t_64_sync_handler+0xa0/0xc4 el0t_64_sync+0x174/0x178 Mem-Info: ... The reason is that the hugetlb pages being released are allocated from movable nodes, and with hugetlb_optimize_vmemmap enabled, vmemmap pages need to be allocated from the same node during the hugetlb pages releasing. With GFP_KERNEL and __GFP_THISNODE set, allocating from movable node is always failed. Fix this problem by removing __GFP_THISNODE. Link: https://lkml.kernel.org/r/20230905124503.24899-1-yuancan@huawei.com Fixes: ad2fa3717b74 ("mm: hugetlb: alloc the vmemmap pages associated with each HugeTLB page") Signed-off-by: Yuan Can <yuancan@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/vmstat: use this_cpu_try_cmpxchg in mod_{zone,node}_stateUros Bizjak1-8/+10
Use this_cpu_try_cmpxchg instead of this_cpu_cmpxchg (*ptr, old, new) == old in mod_zone_state and mod_node_state. x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg). Also, try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg fails. There is no need to re-read the value in the loop. No functional change intended. Link: https://lkml.kernel.org/r/20230904150917.8318-1-ubizjak@gmail.com Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm: convert DAX lock/unlock page to lock/unlock folioMatthew Wilcox (Oracle)3-30/+33
The one caller of DAX lock/unlock page already calls compound_head(), so use page_folio() instead, then use a folio throughout the DAX code to remove uses of page->mapping and page->index. [jane.chu@oracle.com: add comment to mf_generic_kill_procss(), simplify mf_generic_kill_procs:folio initialization] Link: https://lkml.kernel.org/r/20230908222336.186313-1-jane.chu@oracle.com Link: https://lkml.kernel.org/r/20230822231314.349200-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Jane Chu <jane.chu@oracle.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jane Chu <jane.chu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm: remove remnants of SPLIT_RSS_COUNTINGMateusz Guzik7-25/+1
The feature got retired in f1a7941243c1 ("mm: convert mm's rss stats into percpu_counter"), but the patch failed to fully clean it up. Link: https://lkml.kernel.org/r/20230823170556.2281747-1-mjguzik@gmail.com Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Acked-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/vmscan: use folio_migratetype() instead of get_pageblock_migratetype()Vern Hao1-1/+1
In skip_cma(), we can use folio_migratetype() to replace get_pageblock_migratetype(). Link: https://lkml.kernel.org/r/20230825075735.52436-1-user@VERNHAO-MC1 Signed-off-by: Vern Hao <vernhao@tencent.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Zhaoyang Huang <zhaoyang.huang@unisoc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm: refactor si_mem_available()Lorenzo Stoakes1-7/+4
si_mem_available() needlessly places LRU statistics into an array before retrieving only two of them, simply access those directly. In addition, refactor the code so that the blocks of code which calculate the page cache and reclaimable components each resemble one another to clearly indicate we cap both against wmark_low in the same fashion. Link: https://lkml.kernel.org/r/20230827110848.43510-1-lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/hugetlb: fix nodes huge page allocation when there are surplus pagesXueshi Hu1-1/+3
In set_nr_huge_pages(), local variable "count" is used to record persistent_huge_pages(), but when it cames to nodes huge page allocation, the semantics changes to nr_huge_pages. When there exists surplus huge pages and using the interface under /sys/devices/system/node/node*/hugepages to change huge page pool size, this difference can result in the allocation of an unexpected number of huge pages. Steps to reproduce the bug: Starting with: Node 0 Node 1 Total HugePages_Total 0.00 0.00 0.00 HugePages_Free 0.00 0.00 0.00 HugePages_Surp 0.00 0.00 0.00 create 100 huge pages in Node 0 and consume it, then set Node 0 's nr_hugepages to 0. yields: Node 0 Node 1 Total HugePages_Total 200.00 0.00 200.00 HugePages_Free 0.00 0.00 0.00 HugePages_Surp 200.00 0.00 200.00 write 100 to Node 1's nr_hugepages echo 100 > /sys/devices/system/node/node1/\ hugepages/hugepages-2048kB/nr_hugepages gets: Node 0 Node 1 Total HugePages_Total 200.00 400.00 600.00 HugePages_Free 0.00 400.00 400.00 HugePages_Surp 200.00 0.00 200.00 Kernel is expected to create only 100 huge pages and it gives 200. Link: https://lkml.kernel.org/r/20230829033343.467779-1-xueshi.hu@smartx.com Fixes: 9a30523066cd ("hugetlb: add per node hstate attributes") Signed-off-by: Xueshi Hu <xueshi.hu@smartx.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04hugetlb: set hugetlb page flag before optimizing vmemmapMike Kravetz2-9/+25
Currently, vmemmap optimization of hugetlb pages is performed before the hugetlb flag (previously hugetlb destructor) is set identifying it as a hugetlb folio. This means there is a window of time where an ordinary folio does not have all associated vmemmap present. The core mm only expects vmemmap to be potentially optimized for hugetlb and device dax. This can cause problems in code such as memory error handling that may want to write to tail struct pages. There is only one call to perform hugetlb vmemmap optimization today. To fix this issue, simply set the hugetlb flag before that call. There was a similar issue in the free hugetlb path that was previously addressed. The two routines that optimize or restore hugetlb vmemmap should only be passed hugetlb folios/pages. To catch any callers not following this rule, add VM_WARN_ON calls to the routines. In the hugetlb free code paths, some calls could be made to restore vmemmap after clearing the hugetlb flag. This was 'safe' as in these cases vmemmap was already present and the call was a NOOP. However, for consistency these calls where eliminated so that we can add the VM_WARN_ON checks. Link: https://lkml.kernel.org/r/20230829213734.69673-1-mike.kravetz@oracle.com Fixes: f41f2ed43ca5 ("mm: hugetlb: free the vmemmap pages associated with each HugeTLB page") Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: James Houghton <jthoughton@google.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Cc: Usama Arif <usama.arif@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm: fix unaccount of memory on vma_link() failureAnthony Yznaga1-1/+2
Fix insert_vm_struct() so that only accounted memory is unaccounted if vma_link() fails. Link: https://lkml.kernel.org/r/20230830004324.16101-1-anthony.yznaga@oracle.com Fixes: d4af56c5c7c6 ("mm: start tracking VMAs with maple tree") Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/mremap: fix unaccount of memory on vma_merge() failureAnthony Yznaga1-1/+3
Fix mremap so that only accounted memory is unaccounted if the mapping is expandable but vma_merge() fails. Link: https://lkml.kernel.org/r/20230830004549.16131-1-anthony.yznaga@oracle.com Fixes: fdbef6149135 ("mm/mremap: don't account pages in vma_to_resize()") Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> Acked-by: Brian Geffon <bgeffon@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04selftests/mm: gup_longterm: fix a resource leakDing Xiang1-1/+2
The opened file should be closed in run_with_tmpfile(), otherwise resource leak will occur Link: https://lkml.kernel.org/r/20230831093144.7520-1-dingxiang@cmss.chinamobile.com Signed-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/compaction: factor out code to test if we should run compaction for ↵Kemeng Shi1-27/+39
target order We always do zone_watermark_ok check and compaction_suitable check together to test if compaction for target order should be ran. Factor these code out to remove repeat code. Link: https://lkml.kernel.org/r/20230901155141.249860-7-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/compaction: improve comment of is_via_compact_memoryKemeng Shi1-2/+4
We do proactive compaction with order == -1 via 1. /proc/sys/vm/compact_memory 2. /sys/devices/system/node/nodex/compact 3. /proc/sys/vm/compaction_proactiveness Add missed situation in which order == -1. Link: https://lkml.kernel.org/r/20230901155141.249860-6-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/compaction: remove repeat compact_blockskip_flush check in ↵Kemeng Shi1-3/+2
reset_isolation_suitable We have compact_blockskip_flush check in __reset_isolation_suitable, just remove repeat check before __reset_isolation_suitable in compact_blockskip_flush. Link: https://lkml.kernel.org/r/20230901155141.249860-5-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/compaction: correctly return failure with bogus compound_order in strict modeKemeng Shi1-3/+3
In strict mode, we should return 0 if there is any hole in pageblock. If we successfully isolated pages at beginning at pageblock and then have a bogus compound_order outside pageblock in next page. We will abort search loop with blockpfn > end_pfn. Although we will limit blockpfn to end_pfn, we will treat it as a successful isolation in strict mode as blockpfn is not < end_pfn and return partial isolated pages. Then isolate_freepages_range may success unexpectly with hole in isolated range. Link: https://lkml.kernel.org/r/20230901155141.249860-4-shikemeng@huaweicloud.com Fixes: 9fcd6d2e052e ("mm, compaction: skip compound pages by order in free scanner") Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/compaction: call list_is_{first}/{last} more intuitively in ↵Kemeng Shi1-2/+2
move_freelist_{head}/{tail} We use move_freelist_head after list_for_each_entry_reverse to skip recent pages. And there is no need to do actual move if all freepages are searched in list_for_each_entry_reverse, e.g. freepage point to first page in freelist. It's more intuitively to call list_is_first with list entry as the first argument and list head as the second argument to check if list entry is the first list entry instead of call list_is_last with list entry and list head passed in reverse. Similarly, call list_is_last in move_freelist_tail is more intuitively. Link: https://lkml.kernel.org/r/20230901155141.249860-3-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/compaction: use correct list in move_freelist_{head}/{tail}Kemeng Shi1-4/+4
Patch series "Fixes and cleanups to compaction", v3. This is a series to do fix and clean up to compaction. Patch 1-2 fix and clean up freepage list operation. Patch 3-4 fix and clean up isolation of freepages Patch 7 factor code to check if compaction is needed for allocation order. More details can be found in respective patches. This patch (of 6): The freepage is chained with buddy_list in freelist head. Use buddy_list instead of lru to correct the list operation. Link: https://lkml.kernel.org/r/20230901155141.249860-1-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/20230901155141.249860-2-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-02Linux 6.6-rc4v6.6-rc4Linus Torvalds1-1/+1
2023-10-01Merge tag 'kbuild-fixes-v6.6-2' of ↵Linus Torvalds7-15/+41
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - Fix the module compression with xz so the in-kernel decompressor works - Document a kconfig idiom to express an optional dependency between modules - Make modpost, when W=1 is given, detect broken drivers that reference .exit.* sections - Remove unused code * tag 'kbuild-fixes-v6.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: remove stale code for 'source' symlink in packaging scripts modpost: Don't let "driver"s reference .exit.* vmlinux.lds.h: remove unused CPU_KEEP and CPU_DISCARD macros modpost: add missing else to the "of" check Documentation: kbuild: explain handling optional dependencies kbuild: Use CRC32 and a 1MiB dictionary for XZ compressed modules
2023-10-01Merge tag 'mm-hotfixes-stable-2023-10-01-08-34' of ↵Linus Torvalds38-169/+455
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "Fourteen hotfixes, eleven of which are cc:stable. The remainder pertain to issues which were introduced after 6.5" * tag 'mm-hotfixes-stable-2023-10-01-08-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: Crash: add lock to serialize crash hotplug handling selftests/mm: fix awk usage in charge_reserved_hugetlb.sh and hugetlb_reparenting_test.sh that may cause error mm: mempolicy: keep VMA walk if both MPOL_MF_STRICT and MPOL_MF_MOVE are specified mm/damon/vaddr-test: fix memory leak in damon_do_test_apply_three_regions() mm, memcg: reconsider kmem.limit_in_bytes deprecation mm: zswap: fix potential memory corruption on duplicate store arm64: hugetlb: fix set_huge_pte_at() to work with all swap entries mm: hugetlb: add huge page size param to set_huge_pte_at() maple_tree: add MAS_UNDERFLOW and MAS_OVERFLOW states maple_tree: add mas_is_active() to detect in-tree walks nilfs2: fix potential use after free in nilfs_gccache_submit_read_data() mm: abstract moving to the next PFN mm: report success more often from filemap_map_folio_range() fs: binfmt_elf_efpic: fix personality for ELF-FDPIC
2023-10-01Merge tag 'char-misc-6.6-rc4' of ↵Linus Torvalds6-212/+102
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull misc driver fix from Greg KH: "Here is a single, much requested, fix for a set of misc drivers to resolve a much reported regression in the -rc series that has also propagated back to the stable releases. Sorry for the delay, lots of conference travel for a few weeks put me very far behind in patch wrangling. It has been reported by many to resolve the reported problem, and has been in linux-next with no reported issues" * tag 'char-misc-6.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: misc: rtsx: Fix some platforms can not boot and move the l1ss judgment to probe
2023-10-01Merge tag 'tty-6.6-rc4' of ↵Linus Torvalds2-4/+5
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial driver fixes from Greg KH: "Here are two tty/serial driver fixes for 6.6-rc4 that resolve some reported regressions: - revert a n_gsm change that ended up causing problems - 8250_port fix for irq data both have been in linux-next for over a week with no reported problems" * tag 'tty-6.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: Revert "tty: n_gsm: fix UAF in gsm_cleanup_mux" serial: 8250_port: Check IRQ data before use
2023-10-01Merge tag 'x86-urgent-2023-10-01' of ↵Linus Torvalds3-7/+26
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes: a kerneldoc build warning fix, add SRSO mitigation for AMD-derived Hygon processors, and fix a SGX kernel crash in the page fault handler that can trigger when ksgxd races to reclaim the SECS special page, by making the SECS page unswappable" * tag 'x86-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sgx: Resolves SECS reclaim vs. page fault for EAUG race x86/srso: Add SRSO mitigation for Hygon processors x86/kgdb: Fix a kerneldoc warning when build with W=1
2023-10-01Merge tag 'timers-urgent-2023-10-01' of ↵Linus Torvalds1-1/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Ingo Molnar: "Fix a spurious kernel warning during CPU hotplug events that may trigger when timer/hrtimer softirqs are pending, which are otherwise hotplug-safe and don't merit a warning" * tag 'timers-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers: Tag (hr)timer softirq as hotplug safe
2023-10-01Merge tag 'sched-urgent-2023-10-01' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Ingo Molnar: "Fix a RT tasks related lockup/live-lock during CPU offlining" * tag 'sched-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/rt: Fix live lock between select_fallback_rq() and RT push
2023-10-01Merge tag 'perf-urgent-2023-10-01' of ↵Linus Torvalds1-7/+17
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf event fixes from Ingo Molnar: "Misc fixes: work around an AMD microcode bug on certain models, and fix kexec kernel PMI handlers on AMD systems that get loaded on older kernels that have an unexpected register state" * tag 'perf-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/amd: Do not WARN() on every IRQ perf/x86/amd/core: Fix overflow reset on hotplug
2023-10-01kbuild: remove stale code for 'source' symlink in packaging scriptsMasahiro Yamada2-4/+0
Since commit d8131c2965d5 ("kbuild: remove $(MODLIB)/source symlink"), modules_install does not create the 'source' symlink. Remove the stale code from builddeb and kernel.spec. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-10-01modpost: Don't let "driver"s reference .exit.*Uwe Kleine-König1-2/+13
Drivers must not reference functions marked with __exit as these likely are not available when the code is built-in. There are few creative offenders uncovered for example in ARCH=amd64 allmodconfig builds. So only trigger the section mismatch warning for W=1 builds. The dual rule that drivers must not reference .init.* is implemented since commit 0db252452378 ("modpost: don't allow *driver to reference .init.*") which however missed that .exit.* should be handled in the same way. Thanks to Masahiro Yamada and Arnd Bergmann who gave valuable hints to find this improvement. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-10-01vmlinux.lds.h: remove unused CPU_KEEP and CPU_DISCARD macrosMasahiro Yamada1-7/+0
Remove the left-over of commit e24f6628811e ("modpost: remove all traces of cpuinit/cpuexit sections"). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2023-10-01modpost: add missing else to the "of" checkMauricio Faria de Oliveira1-1/+1
Without this 'else' statement, an "usb" name goes into two handlers: the first/previous 'if' statement _AND_ the for-loop over 'devtable', but the latter is useless as it has no 'usb' device_id entry anyway. Tested with allmodconfig before/after patch; no changes to *.mod.c: git checkout v6.6-rc3 make -j$(nproc) allmodconfig make -j$(nproc) olddefconfig make -j$(nproc) find . -name '*.mod.c' | cpio -pd /tmp/before # apply patch make -j$(nproc) find . -name '*.mod.c' | cpio -pd /tmp/after diff -r /tmp/before/ /tmp/after/ # no difference Fixes: acbef7b76629 ("modpost: fix module autoloading for OF devices with generic compatible property") Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-10-01Merge tag 'soc-fixes-6.6' of ↵Linus Torvalds29-90/+179
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull ARM SoC fixes from Arnd Bergmann: "These are the latest bug fixes that have come up in the soc tree. Most of these are fairly minor. Most notably, the majority of changes this time are not for dts files as usual. - Updates to the addresses of the broadcom and aspeed entries in the MAINTAINERS file. - Defconfig updates to address a regression on samsung and a build warning from an unknown Kconfig symbol - Build fixes for the StrongARM and Uniphier platforms - Code fixes for SCMI and FF-A firmware drivers, both of which had a simple bug that resulted in invalid data, and a lesser fix for the optee firmware driver - Multiple fixes for the recently added loongson/loongarch "guts" soc driver - Devicetree fixes for RISC-V on the startfive platform, addressing issues with NOR flash, usb and uart. - Multiple fixes for NXP i.MX8/i.MX9 dts files, fixing problems with clock, gpio, hdmi settings and the Makefile - Bug fixes for i.MX firmware code and the OCOTP soc driver - Multiple fixes for the TI sysc bus driver - Minor dts updates for TI omap dts files, to address boot time warnings and errors" * tag 'soc-fixes-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (35 commits) MAINTAINERS: Fix Florian Fainelli's email address arm64: defconfig: enable syscon-poweroff driver ARM: locomo: fix locomolcd_power declaration soc: loongson: loongson2_guts: Remove unneeded semicolon soc: loongson: loongson2_guts: Convert to devm_platform_ioremap_resource() soc: loongson: loongson_pm2: Populate children syscon nodes dt-bindings: soc: loongson,ls2k-pmc: Allow syscon-reboot/syscon-poweroff as child soc: loongson: loongson_pm2: Drop useless of_device_id compatible dt-bindings: soc: loongson,ls2k-pmc: Use fallbacks for ls2k-pmc compatible soc: loongson: loongson_pm2: Add dependency for INPUT arm64: defconfig: remove CONFIG_COMMON_CLK_NPCM8XX=y ARM: uniphier: fix cache kernel-doc warnings MAINTAINERS: aspeed: Update Andrew's email address MAINTAINERS: aspeed: Update git tree URL firmware: arm_ffa: Don't set the memory region attributes for MEM_LEND arm64: dts: imx: Add imx8mm-prt8mm.dtb to build arm64: dts: imx8mm-evk: Fix hdmi@3d node soc: imx8m: Enable OCOTP clock for imx8mm before reading registers arm64: dts: imx8mp-beacon-kit: Fix audio_pll2 clock arm64: dts: imx8mp: Fix SDMA2/3 clocks ...
2023-10-01Merge tag 'trace-v6.6-rc3' of ↵Linus Torvalds4-8/+56
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Make sure 32-bit applications using user events have aligned access when running on a 64-bit kernel. - Add cond_resched in the loop that handles converting enums in print_fmt string is trace events. - Fix premature wake ups of polling processes in the tracing ring buffer. When a task polls waiting for a percentage of the ring buffer to be filled, the writer still will wake it up at every event. Add the polling's percentage to the "shortest_full" list to tell the writer when to wake it up. - For eventfs dir lookups on dynamic events, an event system's only event could be removed, leaving its dentry with no children. This is totally legitimate. But in eventfs_release() it must not access the children array, as it is only allocated when the dentry has children. * tag 'trace-v6.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: eventfs: Test for dentries array allocated in eventfs_release() tracing/user_events: Align set_bit() address for all archs tracing: relax trace_event_eval_update() execution with cond_resched() ring-buffer: Update "shortest_full" in polling
2023-09-30eventfs: Test for dentries array allocated in eventfs_release()Steven Rostedt (Google)1-1/+1
The dcache_dir_open_wrapper() could be called when a dynamic event is being deleted leaving a dentry with no children. In this case the dlist->dentries array will never be allocated. This needs to be checked for in eventfs_release(), otherwise it will trigger a NULL pointer dereference. Link: https://lore.kernel.org/linux-trace-kernel/20230930090106.1c3164e9@rorschach.local.home Cc: Mark Rutland <mark.rutland@arm.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Fixes: ef36b4f92868 ("eventfs: Remember what dentries were created on dir open") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-30tracing/user_events: Align set_bit() address for all archsBeau Belgrave1-7/+51
All architectures should use a long aligned address passed to set_bit(). User processes can pass either a 32-bit or 64-bit sized value to be updated when tracing is enabled when on a 64-bit kernel. Both cases are ensured to be naturally aligned, however, that is not enough. The address must be long aligned without affecting checks on the value within the user process which require different adjustments for the bit for little and big endian CPUs. Add a compat flag to user_event_enabler that indicates when a 32-bit value is being used on a 64-bit kernel. Long align addresses and correct the bit to be used by set_bit() to account for this alignment. Ensure compat flags are copied during forks and used during deletion clears. Link: https://lore.kernel.org/linux-trace-kernel/20230925230829.341-2-beaub@linux.microsoft.com Link: https://lore.kernel.org/linux-trace-kernel/20230914131102.179100-1-cleger@rivosinc.com/ Cc: stable@vger.kernel.org Fixes: 7235759084a4 ("tracing/user_events: Use remote writes for event enablement") Reported-by: Clément Léger <cleger@rivosinc.com> Suggested-by: Clément Léger <cleger@rivosinc.com> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-30tracing: relax trace_event_eval_update() execution with cond_resched()Clément Léger1-0/+1
When kernel is compiled without preemption, the eval_map_work_func() (which calls trace_event_eval_update()) will not be preempted up to its complete execution. This can actually cause a problem since if another CPU call stop_machine(), the call will have to wait for the eval_map_work_func() function to finish executing in the workqueue before being able to be scheduled. This problem was observe on a SMP system at boot time, when the CPU calling the initcalls executed clocksource_done_booting() which in the end calls stop_machine(). We observed a 1 second delay because one CPU was executing eval_map_work_func() and was not preempted by the stop_machine() task. Adding a call to cond_resched() in trace_event_eval_update() allows other tasks to be executed and thus continue working asynchronously like before without blocking any pending task at boot time. Link: https://lore.kernel.org/linux-trace-kernel/20230929191637.416931-1-cleger@rivosinc.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Clément Léger <cleger@rivosinc.com> Tested-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-30ring-buffer: Update "shortest_full" in pollingSteven Rostedt (Google)1-0/+3
It was discovered that the ring buffer polling was incorrectly stating that read would not block, but that's because polling did not take into account that reads will block if the "buffer-percent" was set. Instead, the ring buffer polling would say reads would not block if there was any data in the ring buffer. This was incorrect behavior from a user space point of view. This was fixed by commit 42fb0a1e84ff by having the polling code check if the ring buffer had more data than what the user specified "buffer percent" had. The problem now is that the polling code did not register itself to the writer that it wanted to wait for a specific "full" value of the ring buffer. The result was that the writer would wake the polling waiter whenever there was a new event. The polling waiter would then wake up, see that there's not enough data in the ring buffer to notify user space and then go back to sleep. The next event would wake it up again. Before the polling fix was added, the code would wake up around 100 times for a hackbench 30 benchmark. After the "fix", due to the constant waking of the writer, it would wake up over 11,0000 times! It would never leave the kernel, so the user space behavior was still "correct", but this definitely is not the desired effect. To fix this, have the polling code add what it's waiting for to the "shortest_full" variable, to tell the writer not to wake it up if the buffer is not as full as it expects to be. Note, after this fix, it appears that the waiter is now woken up around 2x the times it was before (~200). This is a tremendous improvement from the 11,000 times, but I will need to spend some time to see why polling is more aggressive in its wakeups than the read blocking code. Link: https://lore.kernel.org/linux-trace-kernel/20230929180113.01c2cae3@rorschach.local.home Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Fixes: 42fb0a1e84ff ("tracing/ring-buffer: Have polling block on watermark") Reported-by: Julia Lawall <julia.lawall@inria.fr> Tested-by: Julia Lawall <julia.lawall@inria.fr> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-30Merge tag 'dma-mapping-6.6-2023-09-30' of ↵Linus Torvalds2-16/+38
git://git.infradead.org/users/hch/dma-mapping Pull dma-mapping fixes from Christoph Hellwig: - fix the narea calculation in swiotlb initialization (Ross Lagerwall) - fix the check whether a device has used swiotlb (Petr Tesarik) * tag 'dma-mapping-6.6-2023-09-30' of git://git.infradead.org/users/hch/dma-mapping: swiotlb: fix the check whether a device has used software IO TLB swiotlb: use the calculated number of areas
2023-09-30Merge tag 'iomap-6.6-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds2-2/+11
Pull iomap fixes from Darrick Wong: - Handle a race between writing and shrinking block devices by returning EIO - Fix a typo in a comment * tag 'iomap-6.6-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: iomap: Spelling s/preceeding/preceding/g iomap: add a workaround for racy i_size updates on block devices