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Pull io_uring updates from Jens Axboe:
- Greatly improve send zerocopy performance, by enabling coalescing of
sent buffers.
MSG_ZEROCOPY already does this with send(2) and sendmsg(2), but the
io_uring side did not. In local testing, the crossover point for send
zerocopy being faster is now around 3000 byte packets, and it
performs better than the sync syscall variants as well.
This feature relies on a shared branch with net-next, which was
pulled into both branches.
- Unification of how async preparation is done across opcodes.
Previously, opcodes that required extra memory for async retry would
allocate that as needed, using on-stack state until that was the
case. If async retry was needed, the on-stack state was adjusted
appropriately for a retry and then copied to the allocated memory.
This led to some fragile and ugly code, particularly for read/write
handling, and made storage retries more difficult than they needed to
be. Allocate the memory upfront, as it's cheap from our pools, and
use that state consistently both initially and also from the retry
side.
- Move away from using remap_pfn_range() for mapping the rings.
This is really not the right interface to use and can cause lifetime
issues or leaks. Additionally, it means the ring sq/cq arrays need to
be physically contigious, which can cause problems in production with
larger rings when services are restarted, as memory can be very
fragmented at that point.
Move to using vm_insert_page(s) for the ring sq/cq arrays, and apply
the same treatment to mapped ring provided buffers. This also helps
unify the code we have dealing with allocating and mapping memory.
Hard to see in the diffstat as we're adding a few features as well,
but this kills about ~400 lines of code from the codebase as well.
- Add support for bundles for send/recv.
When used with provided buffers, bundles support sending or receiving
more than one buffer at the time, improving the efficiency by only
needing to call into the networking stack once for multiple sends or
receives.
- Tweaks for our accept operations, supporting both a DONTWAIT flag for
skipping poll arm and retry if we can, and a POLLFIRST flag that the
application can use to skip the initial accept attempt and rely
purely on poll for triggering the operation. Both of these have
identical flags on the receive side already.
- Make the task_work ctx locking unconditional.
We had various code paths here that would do a mix of lock/trylock
and set the task_work state to whether or not it was locked. All of
that goes away, we lock it unconditionally and get rid of the state
flag indicating whether it's locked or not.
The state struct still exists as an empty type, can go away in the
future.
- Add support for specifying NOP completion values, allowing it to be
used for error handling testing.
- Use set/test bit for io-wq worker flags. Not strictly needed, but
also doesn't hurt and helps silence a KCSAN warning.
- Cleanups for io-wq locking and work assignments, closing a tiny race
where cancelations would not be able to find the work item reliably.
- Misc fixes, cleanups, and improvements
* tag 'for-6.10/io_uring-20240511' of git://git.kernel.dk/linux: (97 commits)
io_uring: support to inject result for NOP
io_uring: fail NOP if non-zero op flags is passed in
io_uring/net: add IORING_ACCEPT_POLL_FIRST flag
io_uring/net: add IORING_ACCEPT_DONTWAIT flag
io_uring/filetable: don't unnecessarily clear/reset bitmap
io_uring/io-wq: Use set_bit() and test_bit() at worker->flags
io_uring/msg_ring: cleanup posting to IOPOLL vs !IOPOLL ring
io_uring: Require zeroed sqe->len on provided-buffers send
io_uring/notif: disable LAZY_WAKE for linked notifs
io_uring/net: fix sendzc lazy wake polling
io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of re-reading it
io_uring/rw: reinstate thread check for retries
io_uring/notif: implement notification stacking
io_uring/notif: simplify io_notif_flush()
net: add callback for setting a ubuf_info to skb
net: extend ubuf_info callback to ops structure
io_uring/net: support bundles for recv
io_uring/net: support bundles for send
io_uring/kbuf: add helpers for getting/peeking multiple buffers
io_uring/net: add provided buffer support for IORING_OP_SEND
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull netfs updates from Christian Brauner:
"This reworks the netfslib writeback implementation so that pages read
from the cache are written to the cache through ->writepages(),
thereby allowing the fscache page flag to be retired.
The reworking also:
- builds on top of the new writeback_iter() infrastructure
- makes it possible to use vectored write RPCs as discontiguous
streams of pages can be accommodated
- makes it easier to do simultaneous content crypto and stream
division
- provides support for retrying writes and re-dividing a stream
- replaces the ->launder_folio() op, so that ->writepages() is used
instead
- uses mempools to allocate the netfs_io_request and
netfs_io_subrequest structs to avoid allocation failure in the
writeback path
Some code that uses the fscache page flag is retained for
compatibility purposes with nfs and ceph. The code is switched to
using the synonymous private_2 label instead and marked with
deprecation comments.
The merge commit contains additional details on the new algorithm that
I've left out of here as it would probably be excessively detailed.
On top of the netfslib infrastructure this contains the work to
convert cifs over to netfslib"
* tag 'vfs-6.10.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (38 commits)
cifs: Enable large folio support
cifs: Remove some code that's no longer used, part 3
cifs: Remove some code that's no longer used, part 2
cifs: Remove some code that's no longer used, part 1
cifs: Cut over to using netfslib
cifs: Implement netfslib hooks
cifs: Make add_credits_and_wake_if() clear deducted credits
cifs: Add mempools for cifs_io_request and cifs_io_subrequest structs
cifs: Set zero_point in the copy_file_range() and remap_file_range()
cifs: Move cifs_loose_read_iter() and cifs_file_write_iter() to file.c
cifs: Replace the writedata replay bool with a netfs sreq flag
cifs: Make wait_mtu_credits take size_t args
cifs: Use more fields from netfs_io_subrequest
cifs: Replace cifs_writedata with a wrapper around netfs_io_subrequest
cifs: Replace cifs_readdata with a wrapper around netfs_io_subrequest
cifs: Use alternative invalidation to using launder_folio
netfs, afs: Use writeback retry to deal with alternate keys
netfs: Miscellaneous tidy ups
netfs: Remove the old writeback code
netfs: Cut over to using new writeback code
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"This contains the usual miscellaneous features, cleanups, and fixes
for vfs and individual fses.
Features:
- Free up FMODE_* bits. I've freed up bits 6, 7, 8, and 24. That
means we now have six free FMODE_* bits in total (but bit #6
already got used for FMODE_WRITE_RESTRICTED)
- Add FOP_HUGE_PAGES flag (follow-up to FMODE_* cleanup)
- Add fd_raw cleanup class so we can make use of automatic cleanup
provided by CLASS(fd_raw, f)(fd) for O_PATH fds as well
- Optimize seq_puts()
- Simplify __seq_puts()
- Add new anon_inode_getfile_fmode() api to allow specifying f_mode
instead of open-coding it in multiple places
- Annotate struct file_handle with __counted_by() and use
struct_size()
- Warn in get_file() whether f_count resurrection from zero is
attempted (epoll/drm discussion)
- Folio-sophize aio
- Export the subvolume id in statx() for both btrfs and bcachefs
- Relax linkat(AT_EMPTY_PATH) requirements
- Add F_DUPFD_QUERY fcntl() allowing to compare two file descriptors
for dup*() equality replacing kcmp()
Cleanups:
- Compile out swapfile inode checks when swap isn't enabled
- Use (1 << n) notation for FMODE_* bitshifts for clarity
- Remove redundant variable assignment in fs/direct-io
- Cleanup uses of strncpy in orangefs
- Speed up and cleanup writeback
- Move fsparam_string_empty() helper into header since it's currently
open-coded in multiple places
- Add kernel-doc comments to proc_create_net_data_write()
- Don't needlessly read dentry->d_flags twice
Fixes:
- Fix out-of-range warning in nilfs2
- Fix ecryptfs overflow due to wrong encryption packet size
calculation
- Fix overly long line in xfs file_operations (follow-up to FMODE_*
cleanup)
- Don't raise FOP_BUFFER_{R,W}ASYNC for directories in xfs (follow-up
to FMODE_* cleanup)
- Don't call xfs_file_open from xfs_dir_open (follow-up to FMODE_*
cleanup)
- Fix stable offset api to prevent endless loops
- Fix afs file server rotations
- Prevent xattr node from overflowing the eraseblock in jffs2
- Move fdinfo PTRACE_MODE_READ procfs check into the .permission()
operation instead of .open() operation since this caused userspace
regressions"
* tag 'vfs-6.10.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (39 commits)
afs: Fix fileserver rotation getting stuck
selftests: add F_DUPDFD_QUERY selftests
fcntl: add F_DUPFD_QUERY fcntl()
file: add fd_raw cleanup class
fs: WARN when f_count resurrection is attempted
seq_file: Simplify __seq_puts()
seq_file: Optimize seq_puts()
proc: Move fdinfo PTRACE_MODE_READ check into the inode .permission operation
fs: Create anon_inode_getfile_fmode()
xfs: don't call xfs_file_open from xfs_dir_open
xfs: drop fop_flags for directories
xfs: fix overly long line in the file_operations
shmem: Fix shmem_rename2()
libfs: Add simple_offset_rename() API
libfs: Fix simple_offset_rename_exchange()
jffs2: prevent xattr node from overflowing the eraseblock
vfs, swap: compile out IS_SWAPFILE() on swapless configs
vfs: relax linkat() AT_EMPTY_PATH - aka flink() - requirements
fs/direct-io: remove redundant assignment to variable retval
fs/dcache: Re-use value stored to dentry->d_flags instead of re-reading
...
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Pull documentation updates from Jonathan Corbet:
"Another not-too-busy cycle for documentation, including:
- Some build-system changes to detect the variable fonts installed by
some distributions that can break the PDF build.
- Various updates and additions to the Spanish, Chinese, Italian, and
Japanese translations.
- Update the stable-kernel rules to match modern practice
... and the usual array of corrections, updates, and typo fixes"
* tag 'docs-6.10' of git://git.lwn.net/linux: (42 commits)
cgroup: Add documentation for missing zswap memory.stat
kernel-doc: Added "*" in $type_constants2 to fix 'make htmldocs' warning.
docs:core-api: fixed typos and grammar in printk-index page
Documentation: tracing: Fix spelling mistakes
docs/zh_CN/rust: Update the translation of quick-start to 6.9-rc4
docs/zh_CN/rust: Update the translation of general-information to 6.9-rc4
docs/zh_CN/rust: Update the translation of coding-guidelines to 6.9-rc4
docs/zh_CN/rust: Update the translation of arch-support to 6.9-rc4
docs: stable-kernel-rules: fix typo sent->send
docs/zh_CN: remove two inconsistent spaces
docs: scripts/check-variable-fonts.sh: Improve commands for detection
docs: stable-kernel-rules: create special tag to flag 'no backporting'
docs: stable-kernel-rules: explain use of stable@kernel.org (w/o @vger.)
docs: stable-kernel-rules: remove code-labels tags and a indention level
docs: stable-kernel-rules: call mainline by its name and change example
docs: stable-kernel-rules: reduce redundancy
docs, kprobes: Add riscv as supported architecture
Docs: typos/spelling
docs: kernel_include.py: Cope with docutils 0.21
docs: ja_JP/howto: Catch up update in v6.8
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab updates from Vlastimil Babka:
"This time it's mostly random cleanups and fixes, with two performance
fixes that might have significant impact, but limited to systems
experiencing particular bad corner case scenarios rather than general
performance improvements.
The memcg hook changes are going through the mm tree due to
dependencies.
- Prevent stalls when reading /proc/slabinfo (Jianfeng Wang)
This fixes the long-standing problem that can happen with workloads
that have alloc/free patterns resulting in many partially used
slabs (in e.g. dentry cache). Reading /proc/slabinfo will traverse
the long partial slab list under spinlock with disabled irqs and
thus can stall other processes or even trigger the lockup
detection. The traversal is only done to count free objects so that
<active_objs> column can be reported along with <num_objs>.
To avoid affecting fast paths with another shared counter
(attempted in the past) or complex partial list traversal schemes
that allow rescheduling, the chosen solution resorts to
approximation - when the partial list is over 10000 slabs long, we
will only traverse first 5000 slabs from head and tail each and use
the average of those to estimate the whole list. Both head and tail
are used as the slabs near head to tend to have more free objects
than the slabs towards the tail.
It is expected the approximation should not break existing
/proc/slabinfo consumers. The <num_objs> field is still accurate
and reflects the overall kmem_cache footprint. The <active_objs>
was already imprecise due to cpu and percpu-partial slabs, so can't
be relied upon to determine exact cache usage. The difference
between <active_objs> and <num_objs> is mainly useful to determine
the slab fragmentation, and that will be possible even with the
approximation in place.
- Prevent allocating many slabs when a NUMA node is full (Chen Jun)
Currently, on NUMA systems with a node under significantly bigger
pressure than other nodes, the fallback strategy may result in each
kmalloc_node() that can't be safisfied from the preferred node, to
allocate a new slab on a fallback node, and not reuse the slabs
already on that node's partial list.
This is now fixed and partial lists of fallback nodes are checked
even for kmalloc_node() allocations. It's still preferred to
allocate a new slab on the requested node before a fallback, but
only with a GFP_NOWAIT attempt, which will fail quickly when the
node is under a significant memory pressure.
- More SLAB removal related cleanups (Xiu Jianfeng, Hyunmin Lee)
- Fix slub_kunit self-test with hardened freelists (Guenter Roeck)
- Mark racy accesses for KCSAN (linke li)
- Misc cleanups (Xiongwei Song, Haifeng Xu, Sangyun Kim)"
* tag 'slab-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
mm/slub: remove the check for NULL kmalloc_caches
mm/slub: create kmalloc 96 and 192 caches regardless cache size order
mm/slub: mark racy access on slab->freelist
slub: use count_partial_free_approx() in slab_out_of_memory()
slub: introduce count_partial_free_approx()
slub: Set __GFP_COMP in kmem_cache by default
mm/slub: remove duplicate initialization for early_kmem_cache_node_alloc()
mm/slub: correct comment in do_slab_free()
mm/slub, kunit: Use inverted data to corrupt kmem cache
mm/slub: simplify get_partial_node()
mm/slub: add slub_get_cpu_partial() helper
mm/slub: remove the check of !kmem_cache_has_cpu_partial()
mm/slub: Reduce memory consumption in extreme scenarios
mm/slub: mark racy accesses on slab->slabs
mm/slub: remove dummy slabinfo functions
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Alexander Gordeev:
- Store AP Query Configuration Information in a static buffer
- Rework the AP initialization and add missing cleanups to the error
path
- Swap IRQ and AP bus/device registration to avoid race conditions
- Export prot_virt_guest symbol
- Introduce AP configuration changes notifier interface to facilitate
modularization of the AP bus
- Add CONFIG_AP kernel configuration option to allow modularization of
the AP bus
- Rework CONFIG_ZCRYPT_DEBUG kernel configuration option description
and dependency and rename it to CONFIG_AP_DEBUG
- Convert sprintf() and snprintf() to sysfs_emit() in CIO code
- Adjust indentation of RELOCS command build step
- Make crypto performance counters upward compatible
- Convert make_page_secure() and gmap_make_secure() to use folio
- Rework channel-utilization-block (CUB) handling in preparation of
introducing additional CUBs
- Use attribute groups to simplify registration, removal and extension
of measurement-related channel-path sysfs attributes
- Add a per-channel-path binary "ext_measurement" sysfs attribute that
provides access to extended channel-path measurement data
- Export measurement data for all channel-measurement-groups (CMG), not
only for a specific ones. This enables support of new CMG data
formats in userspace without the need for kernel changes
- Add a per-channel-path sysfs attribute "speed_bps" that provides the
operating speed in bits per second or 0 if the operating speed is not
available
- The CIO tracepoint subchannel-type field "st" is incorrectly set to
the value of subchannel-enabled SCHIB "ena" field. Fix that
- Do not forcefully limit vmemmap starting address to MAX_PHYSMEM_BITS
- Consider the maximum physical address available to a DCSS segment
(512GB) when memory layout is set up
- Simplify the virtual memory layout setup by reducing the size of
identity mapping vs vmemmap overlap
- Swap vmalloc and Lowcore/Real Memory Copy areas in virtual memory.
This will allow to place the kernel image next to kernel modules
- Move everyting KASLR related from <asm/setup.h> to <asm/page.h>
- Put virtual memory layout information into a structure to improve
code generation
- Currently __kaslr_offset is the kernel offset in both physical and
virtual memory spaces. Uncouple these offsets to allow uncoupling of
the addresses spaces
- Currently the identity mapping base address is implicit and is always
set to zero. Make it explicit by putting into __identity_base
persistent boot variable and use it in proper context
- Introduce .amode31 section start and end macros AMODE31_START and
AMODE31_END
- Introduce OS_INFO entries that do not reference any data in memory,
but rather provide only values
- Store virtual memory layout in OS_INFO. It is read out by
makedumpfile, crash and other tools
- Store virtual memory layout in VMCORE_INFO. It is read out by crash
and other tools when /proc/kcore device is used
- Create additional PT_LOAD ELF program header that covers kernel image
only, so that vmcore tools could locate kernel text and data when
virtual and physical memory spaces are uncoupled
- Uncouple physical and virtual address spaces
- Map kernel at fixed location when KASLR mode is disabled. The
location is defined by CONFIG_KERNEL_IMAGE_BASE kernel configuration
value.
- Rework deployment of kernel image for both compressed and
uncompressed variants as defined by CONFIG_KERNEL_UNCOMPRESSED kernel
configuration value
- Move .vmlinux.relocs section in front of the compressed kernel. The
interim section rescue step is avoided as result
- Correct modules thunk offset calculation when branch target is more
than 2GB away
- Kernel modules contain their own set of expoline thunks. Now that the
kernel modules area is less than 4GB away from kernel expoline
thunks, make modules use kernel expolines. Also make EXPOLINE_EXTERN
the default if the compiler supports it
- userfaultfd can insert shared zeropages into processes running VMs,
but that is not allowed for s390. Fallback to allocating a fresh
zeroed anonymous folio and insert that instead
- Re-enable shared zeropages for non-PV and non-skeys KVM guests
- Rename hex2bitmap() to ap_hex2bitmap() and export it for external use
- Add ap_config sysfs attribute to provide the means for setting or
displaying adapters, domains and control domains assigned to a
vfio-ap mediated device in a single operation
- Make vfio_ap_mdev_link_queue() ignore duplicate link requests
- Add write support to ap_config sysfs attribute to allow atomic update
a vfio-ap mediated device state
- Document ap_config sysfs attribute
- Function os_info_old_init() is expected to be called only from a
regular kdump kernel. Enable it to be called from a stand-alone dump
kernel
- Address gcc -Warray-bounds warning and fix array size in struct
os_info
- s390 does not support SMBIOS, so drop unneeded CONFIG_DMI checks
- Use unwinder instead of __builtin_return_address() with ftrace to
prevent returning of undefined values
- Sections .hash and .gnu.hash are only created when CONFIG_PIE_BUILD
kernel is enabled. Drop these for the case CONFIG_PIE_BUILD is
disabled
- Compile kernel with -fPIC and link with -no-pie to allow kpatch
feature always succeed and drop the whole CONFIG_PIE_BUILD
option-enabled code
- Add missing virt_to_phys() converter for VSIE facility and crypto
control blocks
* tag 's390-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits)
Revert "s390: Relocate vmlinux ELF data to virtual address space"
KVM: s390: vsie: Use virt_to_phys for crypto control block
s390: Relocate vmlinux ELF data to virtual address space
s390: Compile kernel with -fPIC and link with -no-pie
s390: vmlinux.lds.S: Drop .hash and .gnu.hash for !CONFIG_PIE_BUILD
s390/ftrace: Use unwinder instead of __builtin_return_address()
s390/pci: Drop unneeded reference to CONFIG_DMI
s390/os_info: Fix array size in struct os_info
s390/os_info: Initialize old os_info in standalone dump kernel
docs: Update s390 vfio-ap doc for ap_config sysfs attribute
s390/vfio-ap: Add write support to sysfs attr ap_config
s390/vfio-ap: Ignore duplicate link requests in vfio_ap_mdev_link_queue
s390/vfio-ap: Add sysfs attr, ap_config, to export mdev state
s390/ap: Externalize AP bus specific bitmap reading function
s390/mm: Re-enable the shared zeropage for !PV and !skeys KVM guests
mm/userfaultfd: Do not place zeropages when zeropages are disallowed
s390/expoline: Make modules use kernel expolines
s390/nospec: Correct modules thunk offset calculation
s390/boot: Do not rescue .vmlinux.relocs section
s390/boot: Rework deployment of the kernel image
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM fixes from Andrew Morton:
"18 hotfixes, 7 of which are cc:stable.
More fixups for this cycle's page_owner updates. And a few userfaultfd
fixes. Otherwise, random singletons - see the individual changelogs
for details"
* tag 'mm-hotfixes-stable-2024-05-10-13-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mailmap: add entry for Barry Song
selftests/mm: fix powerpc ARCH check
mailmap: add entry for John Garry
XArray: set the marks correctly when splitting an entry
selftests/vDSO: fix runtime errors on LoongArch
selftests/vDSO: fix building errors on LoongArch
mm,page_owner: don't remove __GFP_NOLOCKDEP in add_stack_record_to_list
fs/proc/task_mmu: fix uffd-wp confusion in pagemap_scan_pmd_entry()
fs/proc/task_mmu: fix loss of young/dirty bits during pagemap scan
mm/vmalloc: fix return value of vb_alloc if size is 0
mm: use memalloc_nofs_save() in page_cache_ra_order()
kmsan: compiler_types: declare __no_sanitize_or_inline
lib/test_xarray.c: fix error assumptions on check_xa_multi_store_adv_add()
tools: fix userspace compilation with new test_xarray changes
MAINTAINERS: update URL's for KEYS/KEYRINGS_INTEGRITY and TPM DEVICE DRIVER
mm: page_owner: fix wrong information in dump_page_owner
maple_tree: fix mas_empty_area_rev() null pointer dereference
mm/userfaultfd: reset ptes when close() for wr-protected ones
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Otherwise we'll generate false lockdep positives.
Link: https://lkml.kernel.org/r/20240429082828.1615986-1-hch@lst.de
Fixes: 217b2119b9e2 ("mm,page_owner: implement the tracking of the stacks count")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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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>
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See commit f2c817bed58d ("mm: use memalloc_nofs_save in readahead path"),
ensure that page_cache_ra_order() do not attempt to reclaim file-backed
pages too, or it leads to a deadlock, found issue when test ext4 large
folio.
INFO: task DataXceiver for:7494 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:DataXceiver for state:D stack:0 pid:7494 ppid:1 flags:0x00000200
Call trace:
__switch_to+0x14c/0x240
__schedule+0x82c/0xdd0
schedule+0x58/0xf0
io_schedule+0x24/0xa0
__folio_lock+0x130/0x300
migrate_pages_batch+0x378/0x918
migrate_pages+0x350/0x700
compact_zone+0x63c/0xb38
compact_zone_order+0xc0/0x118
try_to_compact_pages+0xb0/0x280
__alloc_pages_direct_compact+0x98/0x248
__alloc_pages+0x510/0x1110
alloc_pages+0x9c/0x130
folio_alloc+0x20/0x78
filemap_alloc_folio+0x8c/0x1b0
page_cache_ra_order+0x174/0x308
ondemand_readahead+0x1c8/0x2b8
page_cache_async_ra+0x68/0xb8
filemap_readahead.isra.0+0x64/0xa8
filemap_get_pages+0x3fc/0x5b0
filemap_splice_read+0xf4/0x280
ext4_file_splice_read+0x2c/0x48 [ext4]
vfs_splice_read.part.0+0xa8/0x118
splice_direct_to_actor+0xbc/0x288
do_splice_direct+0x9c/0x108
do_sendfile+0x328/0x468
__arm64_sys_sendfile64+0x8c/0x148
invoke_syscall+0x4c/0x118
el0_svc_common.constprop.0+0xc8/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x4c/0x1f8
el0t_64_sync_handler+0xc0/0xc8
el0t_64_sync+0x188/0x190
Link: https://lkml.kernel.org/r/20240426112938.124740-1-wangkefeng.wang@huawei.com
Fixes: 793917d997df ("mm/readahead: Add large folio readahead")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zhang Yi <yi.zhang@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
With commit ea4b5b33bf8a ("mm,page_owner: update metadata for tail
pages"), new API __update_page_owner_handle was introduced and arguemnt
was passed in wrong order from __set_page_owner and thus page_owner is
giving wrong data.
[ 15.982420] page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL), pid 80, tgid -1210279584 (insmod), ts 80, free_ts 0
Fixing the same.
Correct output:
[ 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
Link: https://lkml.kernel.org/r/20240424111838.3782931-1-hariom1.p@samsung.com
Fixes: ea4b5b33bf8a ("mm,page_owner: update metadata for tail pages")
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Signed-off-by: Hariom Panthi <hariom1.p@samsung.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
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>
|
|
If the same size kmalloc cache already exists, it should not be created
again. So there is the check for NULL kmalloc_caches before calling the
kmalloc creation function. However, new_kmalloc_cache() itself checks NULL
kmalloc_cahces before cache creation. Therefore, the NULL check is not
necessary in this function.
Signed-off-by: Hyunmin Lee <hyunminlr@gmail.com>
Co-developed-by: Jeungwoo Yoo <casionwoo@gmail.com>
Signed-off-by: Jeungwoo Yoo <casionwoo@gmail.com>
Co-developed-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
|
For SLAB the kmalloc caches needed to be created in ascending sizes in
order. However, the constraint is not necessary anymore because SLAB has
been removed and SLUB doesn't need to comply with the constraint. Thus,
kmalloc 96 and 192 caches can be created after the other size kmalloc
caches are created instead of checking every time to find their order to
be created. Also, this change could prevent engineers from being confused
by the removed constraint.
Signed-off-by: Hyunmin Lee <hyunminlr@gmail.com>
Co-developed-by: Jeungwoo Yoo <casionwoo@gmail.com>
Signed-off-by: Jeungwoo Yoo <casionwoo@gmail.com>
Co-developed-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
|
In deactivate_slab(), slab->freelist can be changed concurrently. Mark
data race on slab->freelist as benign using READ_ONCE.
This patch is aimed at reducing the number of benign races reported by
KCSAN in order to focus future debugging effort on harmful races.
Signed-off-by: linke li <lilinke99@qq.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
|
Export writeback_iter() so that it can be used by netfslib as a module.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Christoph Hellwig <hch@lst.de>
cc: linux-mm@kvack.org
|
|
Implement a replacement for launder_folio. The key feature of
invalidate_inode_pages2() is that it locks each folio individually, unmaps
it to prevent mmap'd accesses interfering and calls the ->launder_folio()
address_space op to flush it. This has problems: firstly, each folio is
written individually as one or more small writes; secondly, adjacent folios
cannot be added so easily into the laundry; thirdly, it's yet another op to
implement.
Instead, use the invalidate lock to cause anyone wanting to add a folio to
the inode to wait, then unmap all the folios if we have mmaps, then,
conditionally, use ->writepages() to flush any dirty data back and then
discard all pages.
The invalidate lock prevents ->read_iter(), ->write_iter() and faulting
through mmap all from adding pages for the duration.
This is then used from netfslib to handle the flusing in unbuffered and
direct writes.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: Miklos Szeredi <miklos@szeredi.hu>
cc: Trond Myklebust <trond.myklebust@hammerspace.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Andrew Morton <akpm@linux-foundation.org>
cc: Alexander Viro <viro@zeniv.linux.org.uk>
cc: Christian Brauner <brauner@kernel.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-mm@kvack.org
cc: linux-fsdevel@vger.kernel.org
cc: netfs@lists.linux.dev
cc: v9fs@lists.linux.dev
cc: linux-afs@lists.infradead.org
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: devel@lists.orangefs.org
|
|
Commit 284f17ac13fe ("mm/slub: handle bulk and single object freeing
separately") splits single and bulk object freeing in two functions
slab_free() and slab_free_bulk() which leads slab_free() to call
slab_free_hook() directly instead of slab_free_freelist_hook().
If `init_on_free` is set, slab_free_hook() zeroes the object.
Afterward, if `slub_debug=F` and `CONFIG_SLAB_FREELIST_HARDENED` are
set, the do_slab_free() slowpath executes freelist consistency
checks and try to decode a zeroed freepointer which leads to a
"Freepointer corrupt" detection in check_object().
During bulk free, slab_free_freelist_hook() isn't affected as it always
sets it objects freepointer using set_freepointer() to maintain its
reconstructed freelist after `init_on_free`.
For single free, object's freepointer thus needs to be avoided when
stored outside the object if `init_on_free` is set. The freepointer left
as is, check_object() may later detect an invalid pointer value due to
objects overflow.
To reproduce, set `slub_debug=FU init_on_free=1 log_level=7` on the
command line of a kernel build with `CONFIG_SLAB_FREELIST_HARDENED=y`.
dmesg sample log:
[ 10.708715] =============================================================================
[ 10.710323] BUG kmalloc-rnd-05-32 (Tainted: G B T ): Freepointer corrupt
[ 10.712695] -----------------------------------------------------------------------------
[ 10.712695]
[ 10.712695] Slab 0xffffd8bdc400d580 objects=32 used=4 fp=0xffff9d9a80356f80 flags=0x200000000000a00(workingset|slab|node=0|zone=2)
[ 10.716698] Object 0xffff9d9a80356600 @offset=1536 fp=0x7ee4f480ce0ecd7c
[ 10.716698]
[ 10.716698] Bytes b4 ffff9d9a803565f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 10.720703] Object ffff9d9a80356600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 10.720703] Object ffff9d9a80356610: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 10.724696] Padding ffff9d9a8035666c: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
[ 10.724696] Padding ffff9d9a8035667c: 00 00 00 00 ....
[ 10.724696] FIX kmalloc-rnd-05-32: Object at 0xffff9d9a80356600 not freed
Fixes: 284f17ac13fe ("mm/slub: handle bulk and single object freeing separately")
Cc: <stable@vger.kernel.org>
Co-developed-by: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Nicolas Bouchinet <nicolas.bouchinet@ssi.gouv.fr>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
|
Remove the PG_fscache alias for PG_private_2 and use the latter directly.
Use of this flag for marking pages undergoing writing to the cache should
be considered deprecated and the folios should be marked dirty instead and
the write done in ->writepages().
Note that PG_private_2 itself should be considered deprecated and up for
future removal by the MM folks too.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Xiubo Li <xiubli@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: Tom Talpey <tom@talpey.com>
cc: Bharath SM <bharathsm@microsoft.com>
cc: Trond Myklebust <trond.myklebust@hammerspace.com>
cc: Anna Schumaker <anna@kernel.org>
cc: netfs@lists.linux.dev
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
|
|
When I did memory failure tests recently, below warning occurs:
DEBUG_LOCKS_WARN_ON(1)
WARNING: CPU: 8 PID: 1011 at kernel/locking/lockdep.c:232 __lock_acquire+0xccb/0x1ca0
Modules linked in: mce_inject hwpoison_inject
CPU: 8 PID: 1011 Comm: bash Kdump: loaded Not tainted 6.9.0-rc3-next-20240410-00012-gdb69f219f4be #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RIP: 0010:__lock_acquire+0xccb/0x1ca0
RSP: 0018:ffffa7a1c7fe3bd0 EFLAGS: 00000082
RAX: 0000000000000000 RBX: eb851eb853975fcf RCX: ffffa1ce5fc1c9c8
RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffffa1ce5fc1c9c0
RBP: ffffa1c6865d3280 R08: ffffffffb0f570a8 R09: 0000000000009ffb
R10: 0000000000000286 R11: ffffffffb0f2ad50 R12: ffffa1c6865d3d10
R13: ffffa1c6865d3c70 R14: 0000000000000000 R15: 0000000000000004
FS: 00007ff9f32aa740(0000) GS:ffffa1ce5fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff9f3134ba0 CR3: 00000008484e4000 CR4: 00000000000006f0
Call Trace:
<TASK>
lock_acquire+0xbe/0x2d0
_raw_spin_lock_irqsave+0x3a/0x60
hugepage_subpool_put_pages.part.0+0xe/0xc0
free_huge_folio+0x253/0x3f0
dissolve_free_huge_page+0x147/0x210
__page_handle_poison+0x9/0x70
memory_failure+0x4e6/0x8c0
hard_offline_page_store+0x55/0xa0
kernfs_fop_write_iter+0x12c/0x1d0
vfs_write+0x380/0x540
ksys_write+0x64/0xe0
do_syscall_64+0xbc/0x1d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff9f3114887
RSP: 002b:00007ffecbacb458 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007ff9f3114887
RDX: 000000000000000c RSI: 0000564494164e10 RDI: 0000000000000001
RBP: 0000564494164e10 R08: 00007ff9f31d1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007ff9f321b780 R14: 00007ff9f3217600 R15: 00007ff9f3216a00
</TASK>
Kernel panic - not syncing: kernel: panic_on_warn set ...
CPU: 8 PID: 1011 Comm: bash Kdump: loaded Not tainted 6.9.0-rc3-next-20240410-00012-gdb69f219f4be #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
panic+0x326/0x350
check_panic_on_warn+0x4f/0x50
__warn+0x98/0x190
report_bug+0x18e/0x1a0
handle_bug+0x3d/0x70
exc_invalid_op+0x18/0x70
asm_exc_invalid_op+0x1a/0x20
RIP: 0010:__lock_acquire+0xccb/0x1ca0
RSP: 0018:ffffa7a1c7fe3bd0 EFLAGS: 00000082
RAX: 0000000000000000 RBX: eb851eb853975fcf RCX: ffffa1ce5fc1c9c8
RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffffa1ce5fc1c9c0
RBP: ffffa1c6865d3280 R08: ffffffffb0f570a8 R09: 0000000000009ffb
R10: 0000000000000286 R11: ffffffffb0f2ad50 R12: ffffa1c6865d3d10
R13: ffffa1c6865d3c70 R14: 0000000000000000 R15: 0000000000000004
lock_acquire+0xbe/0x2d0
_raw_spin_lock_irqsave+0x3a/0x60
hugepage_subpool_put_pages.part.0+0xe/0xc0
free_huge_folio+0x253/0x3f0
dissolve_free_huge_page+0x147/0x210
__page_handle_poison+0x9/0x70
memory_failure+0x4e6/0x8c0
hard_offline_page_store+0x55/0xa0
kernfs_fop_write_iter+0x12c/0x1d0
vfs_write+0x380/0x540
ksys_write+0x64/0xe0
do_syscall_64+0xbc/0x1d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff9f3114887
RSP: 002b:00007ffecbacb458 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007ff9f3114887
RDX: 000000000000000c RSI: 0000564494164e10 RDI: 0000000000000001
RBP: 0000564494164e10 R08: 00007ff9f31d1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007ff9f321b780 R14: 00007ff9f3217600 R15: 00007ff9f3216a00
</TASK>
After git bisecting and digging into the code, I believe the root cause is
that _deferred_list field of folio is unioned with _hugetlb_subpool field.
In __update_and_free_hugetlb_folio(), folio->_deferred_list is
initialized leading to corrupted folio->_hugetlb_subpool when folio is
hugetlb. Later free_huge_folio() will use _hugetlb_subpool and above
warning happens.
But it is assumed hugetlb flag must have been cleared when calling
folio_put() in update_and_free_hugetlb_folio(). This assumption is broken
due to below race:
CPU1 CPU2
dissolve_free_huge_page update_and_free_pages_bulk
update_and_free_hugetlb_folio hugetlb_vmemmap_restore_folios
folio_clear_hugetlb_vmemmap_optimized
clear_flag = folio_test_hugetlb_vmemmap_optimized
if (clear_flag) <-- False, it's already cleared.
__folio_clear_hugetlb(folio) <-- Hugetlb is not cleared.
folio_put
free_huge_folio <-- free_the_page is expected.
list_for_each_entry()
__folio_clear_hugetlb <-- Too late.
Fix this issue by checking whether folio is hugetlb directly instead of
checking clear_flag to close the race window.
Link: https://lkml.kernel.org/r/20240419085819.1901645-1-linmiaohe@huawei.com
Fixes: 32c877191e02 ("hugetlb: do not clear hugetlb dtor until allocating vmemmap")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit 9acad7ba3e25 ("hugetlb: use vmf_anon_prepare() instead of
anon_vma_prepare()") may bailout after allocating a folio if we do not
hold the mmap lock. When this occurs, vmf_anon_prepare() will release the
vma lock. Hugetlb then attempts to call restore_reserve_on_error(), which
depends on the vma lock being held.
We can move vmf_anon_prepare() prior to the folio allocation in order to
avoid calling restore_reserve_on_error() without the vma lock.
Link: https://lkml.kernel.org/r/ZiFqSrSRLhIV91og@fedora
Fixes: 9acad7ba3e25 ("hugetlb: use vmf_anon_prepare() instead of anon_vma_prepare()")
Reported-by: syzbot+ad1b592fc4483655438b@syzkaller.appspotmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Christian reports a NULL deref in zswap that he bisected down to the zswap
shrinker. The issue also cropped up in the bug trackers of libguestfs [1]
and the Red Hat bugzilla [2].
The problem is that when memcg is disabled with the boot time flag, the
zswap shrinker might get called with sc->memcg == NULL. This is okay in
many places, like the lruvec operations. But it crashes in
memcg_page_state() - which is only used due to the non-node accounting of
cgroup's the zswap memory to begin with.
Nhat spotted that the memcg can be NULL in the memcg-disabled case, and I
was then able to reproduce the crash locally as well.
[1] https://github.com/libguestfs/libguestfs/issues/139
[2] https://bugzilla.redhat.com/show_bug.cgi?id=2275252
Link: https://lkml.kernel.org/r/20240418124043.GC1055428@cmpxchg.org
Link: https://lkml.kernel.org/r/20240417143324.GA1055428@cmpxchg.org
Fixes: b5ba474f3f51 ("zswap: shrink zswap pool based on memory pressure")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Christian Heusel <christian@heusel.eu>
Debugged-by: Nhat Pham <nphamcs@gmail.com>
Suggested-by: Nhat Pham <nphamcs@gmail.com>
Tested-by: Christian Heusel <christian@heusel.eu>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Richard W.M. Jones <rjones@redhat.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: <stable@vger.kernel.org> [v6.8]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The current folio_test_hugetlb() can be fooled by a concurrent folio split
into returning true for a folio which has never belonged to hugetlbfs.
This can't happen if the caller holds a refcount on it, but we have a few
places (memory-failure, compaction, procfs) which do not and should not
take a speculative reference.
Since hugetlb pages do not use individual page mapcounts (they are always
fully mapped and use the entire_mapcount field to record the number of
mappings), the PageType field is available now that page_mapcount()
ignores the value in this field.
In compaction and with CONFIG_DEBUG_VM enabled, the current implementation
can result in an oops, as reported by Luis. This happens since 9c5ccf2db04b
("mm: remove HUGETLB_PAGE_DTOR") effectively added some VM_BUG_ON() checks
in the PageHuge() testing path.
[willy@infradead.org: update vmcoreinfo]
Link: https://lkml.kernel.org/r/ZgGZUvsdhaT1Va-T@casper.infradead.org
Link: https://lkml.kernel.org/r/20240321142448.1645400-6-willy@infradead.org
Fixes: 9c5ccf2db04b ("mm: remove HUGETLB_PAGE_DTOR")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Luis Chamberlain <mcgrof@kernel.org>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218227
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
There is a recent report on UFFDIO_COPY over hugetlb:
https://lore.kernel.org/all/000000000000ee06de0616177560@google.com/
350: lockdep_assert_held(&hugetlb_lock);
Should be an issue in hugetlb but triggered in an userfault context, where
it goes into the unlikely path where two threads modifying the resv map
together. Mike has a fix in that path for resv uncharge but it looks like
the locking criteria was overlooked: hugetlb_cgroup_uncharge_folio_rsvd()
will update the cgroup pointer, so it requires to be called with the lock
held.
Link: https://lkml.kernel.org/r/20240417211836.2742593-3-peterx@redhat.com
Fixes: 79aa925bf239 ("hugetlb_cgroup: fix reservation accounting")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: syzbot+4b8077a5fccc61c385a1@syzkaller.appspotmail.com
Reviewed-by: Mina Almasry <almasrymina@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit 839195352d82 ("mm/shuffle: remove dynamic reconfiguration")
removed the dynamic reconfiguration capabilities from the shuffle page
allocator. This means that, now, we don't have any perspective of an
"autodetection of memory-side-cache" that triggers the enablement of the
shuffle page allocator.
Therefore, let the documentation reflect that the only way to enable
the shuffle page allocator is by setting `page_alloc.shuffle=1`.
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240422142007.1062231-1-mcanal@igalia.com
|
|
slab_out_of_memory() uses count_partial() to get the exact count
of free objects for each node. As it may get called in the slab
allocation path, count_partial_free_approx() can be used to avoid
the risk and overhead of traversing a long partial slab list.
At the same time, show_slab_objects() still uses count_partial().
Thus, slub users can still have the option to access the exact
count of objects via sysfs if the overhead is acceptable to them.
Signed-off-by: Jianfeng Wang <jianfeng.w.wang@oracle.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
|
When reading "/proc/slabinfo", the kernel needs to report the number
of free objects for each kmem_cache. The current implementation uses
count_partial() to get it by scanning each kmem_cache_node's partial
slab list and summing free objects from every partial slab. This
process must hold per-kmem_cache_node spinlock and disable IRQ, and
may take a long time. Consequently, it can block slab allocations on
other CPUs and cause timeouts for network devices, when the partial
list is long. In production, even NMI watchdog can be triggered due
to this matter: e.g., for "buffer_head", the number of partial slabs
was observed to be ~1M in one kmem_cache_node. This problem was also
confirmed by others [1-3].
Iterating a partial list to get the exact count of objects can cause
soft lockups for a long list with or without the lock (e.g., if
preemption is disabled), and may not be very useful: the object count
can change after the lock is released. The approach of maintaining
free-object counters requires atomic operations on the fast path [3].
So, the fix is to introduce count_partial_free_approx(). This function
can be used for getting the free object count in a kmem_cache_node's
partial list. It limits the number of slabs to scan and avoids scanning
the whole list by giving an approximation for a long list. Suppose the
limit is N. If the list's length is not greater than N, output the exact
count by traversing the list; if its length is greater than N, output an
approximated count by traversing a subset of the list. The proposed
method is to scan N/2 slabs from the list's head and N/2 slabs from
the tail. For a partial list with ~280K slabs, benchmarks show that
it performs better than just counting from the list's head, after slabs
get sorted by kmem_cache_shrink(). Default the limit to 10000, as it
produces an approximation within 1% of the exact count for both
scenarios. Then, use count_partial_free_approx() in get_slabinfo().
Benchmarks: Diff = (exact - approximated) / exact
* Normal case (w/o kmem_cache_shrink()):
| MAX_TO_SCAN | Diff (count from head)| Diff (count head+tail)|
| 1000 | 0.43 % | 1.09 % |
| 5000 | 0.06 % | 0.37 % |
| 10000 | 0.02 % | 0.16 % |
| 20000 | 0.009 % | -0.003 % |
* Skewed case (w/ kmem_cache_shrink()):
| MAX_TO_SCAN | Diff (count from head)| Diff (count head+tail)|
| 1000 | 12.46 % | 6.75 % |
| 5000 | 5.38 % | 1.27 % |
| 10000 | 4.99 % | 0.22 % |
| 20000 | 4.86 % | -0.06 % |
[1] https://lore.kernel.org/linux-mm/alpine.DEB.2.21.2003031602460.1537@www.lameter.com/T/
[2] https://lore.kernel.org/lkml/alpine.DEB.2.22.394.2008071258020.55871@www.lameter.com/T/
[3] https://lore.kernel.org/lkml/1e01092b-140d-2bab-aeba-321a74a194ee@linux.com/T/
Signed-off-by: Jianfeng Wang <jianfeng.w.wang@oracle.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
|
s390x must disable shared zeropages for processes running VMs, because
the VMs could end up making use of "storage keys" or protected
virtualization, which are incompatible with shared zeropages.
Yet, with userfaultfd it is possible to insert shared zeropages into
such processes. Let's fallback to simply allocating a fresh zeroed
anonymous folio and insert that instead.
mm_forbids_zeropage() was introduced in commit 593befa6ab74 ("mm: introduce
mm_forbids_zeropage function"), briefly before userfaultfd went
upstream.
Note that we don't want to fail the UFFDIO_ZEROPAGE request like we do
for hugetlb, it would be rather unexpected. Further, we also
cannot really indicated "not supported" to user space ahead of time: it
could be that the MM disallows zeropages after userfaultfd was already
registered.
[ agordeev: Fixed checkpatch complaints ]
Fixes: c1a4de99fada ("userfaultfd: mcopy_atomic|mfill_zeropage: UFFDIO_COPY|UFFDIO_ZEROPAGE preparation")
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/20240411161441.910170-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
|
https://lore.kernel.org/r/20240415152057.4605-1-cel@kernel.org
Pull shmem_rename2() offset fixes from Chuck Lever:
The existing code in shmem_rename2() allocates a fresh directory
offset value when renaming over an existing destination entry. User
space does not expect this behavior. In particular, applications
that rename while walking a directory can loop indefinitely because
they never reach the end of the directory.
* 'Fix shmem_rename2 directory offset calculation' of https://lore.kernel.org/r/20240415152057.4605-1-cel@kernel.org: (3 commits)
shmem: Fix shmem_rename2()
libfs: Add simple_offset_rename() API
libfs: Fix simple_offset_rename_exchange()
fs/libfs.c | 55 +++++++++++++++++++++++++++++++++++++++++-----
include/linux/fs.h | 2 ++
mm/shmem.c | 3 +--
3 files changed, 52 insertions(+), 8 deletions(-)
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
I'm about to fix a tmpfs rename bug that requires the use of
internal simple_offset helpers that are not available in mm/shmem.c
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20240415152057.4605-3-cel@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
In order to minimize code size (CONFIG_CC_OPTIMIZE_FOR_SIZE=y),
compiler might choose to make a regular function call (out-of-line) for
shmem_is_huge() instead of inlining it. When transparent hugepages are
disabled (CONFIG_TRANSPARENT_HUGEPAGE=n), it can cause compilation
error.
mm/shmem.c: In function `shmem_getattr':
./include/linux/huge_mm.h:383:27: note: in expansion of macro `BUILD_BUG'
383 | #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
| ^~~~~~~~~
mm/shmem.c:1148:33: note: in expansion of macro `HPAGE_PMD_SIZE'
1148 | stat->blksize = HPAGE_PMD_SIZE;
To prevent the possible error, always inline shmem_is_huge() when
transparent hugepages are disabled.
Link: https://lkml.kernel.org/r/20240409155407.2322714-1-sumanthk@linux.ibm.com
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Kefeng Wang reported that he was seeing some memory leaks with kmemleak
with page_owner enabled.
The reason is that we enable the page_owner_inited static branch and then
proceed with the linking of stack_list struct to dummy_stack, which means
that exists a race window between these two steps where we can have pages
already being allocated calling add_stack_record_to_list(), allocating
objects and linking them to stack_list, but then we set stack_list
pointing to dummy_stack in init_page_owner. Which means that the objects
that have been allocated during that time window are unreferenced and
lost.
Fix this by deferring the enablement of the branch until we have properly
set up the list.
Link: https://lkml.kernel.org/r/20240409131715.13632-1-osalvador@suse.de
Fixes: 4bedfb314bdd ("mm,page_owner: maintain own list of stack_records structs")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Closes: https://lore.kernel.org/linux-mm/74b147b0-718d-4d50-be75-d6afc801cd24@huawei.com/
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When I did hard offline test with hugetlb pages, below deadlock occurs:
======================================================
WARNING: possible circular locking dependency detected
6.8.0-11409-gf6cef5f8c37f #1 Not tainted
------------------------------------------------------
bash/46904 is trying to acquire lock:
ffffffffabe68910 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_slow_dec+0x16/0x60
but task is already holding lock:
ffffffffabf92ea8 (pcp_batch_high_lock){+.+.}-{3:3}, at: zone_pcp_disable+0x16/0x40
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (pcp_batch_high_lock){+.+.}-{3:3}:
__mutex_lock+0x6c/0x770
page_alloc_cpu_online+0x3c/0x70
cpuhp_invoke_callback+0x397/0x5f0
__cpuhp_invoke_callback_range+0x71/0xe0
_cpu_up+0xeb/0x210
cpu_up+0x91/0xe0
cpuhp_bringup_mask+0x49/0xb0
bringup_nonboot_cpus+0xb7/0xe0
smp_init+0x25/0xa0
kernel_init_freeable+0x15f/0x3e0
kernel_init+0x15/0x1b0
ret_from_fork+0x2f/0x50
ret_from_fork_asm+0x1a/0x30
-> #0 (cpu_hotplug_lock){++++}-{0:0}:
__lock_acquire+0x1298/0x1cd0
lock_acquire+0xc0/0x2b0
cpus_read_lock+0x2a/0xc0
static_key_slow_dec+0x16/0x60
__hugetlb_vmemmap_restore_folio+0x1b9/0x200
dissolve_free_huge_page+0x211/0x260
__page_handle_poison+0x45/0xc0
memory_failure+0x65e/0xc70
hard_offline_page_store+0x55/0xa0
kernfs_fop_write_iter+0x12c/0x1d0
vfs_write+0x387/0x550
ksys_write+0x64/0xe0
do_syscall_64+0xca/0x1e0
entry_SYSCALL_64_after_hwframe+0x6d/0x75
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(pcp_batch_high_lock);
lock(cpu_hotplug_lock);
lock(pcp_batch_high_lock);
rlock(cpu_hotplug_lock);
*** DEADLOCK ***
5 locks held by bash/46904:
#0: ffff98f6c3bb23f0 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x64/0xe0
#1: ffff98f6c328e488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xf8/0x1d0
#2: ffff98ef83b31890 (kn->active#113){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x100/0x1d0
#3: ffffffffabf9db48 (mf_mutex){+.+.}-{3:3}, at: memory_failure+0x44/0xc70
#4: ffffffffabf92ea8 (pcp_batch_high_lock){+.+.}-{3:3}, at: zone_pcp_disable+0x16/0x40
stack backtrace:
CPU: 10 PID: 46904 Comm: bash Kdump: loaded Not tainted 6.8.0-11409-gf6cef5f8c37f #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x68/0xa0
check_noncircular+0x129/0x140
__lock_acquire+0x1298/0x1cd0
lock_acquire+0xc0/0x2b0
cpus_read_lock+0x2a/0xc0
static_key_slow_dec+0x16/0x60
__hugetlb_vmemmap_restore_folio+0x1b9/0x200
dissolve_free_huge_page+0x211/0x260
__page_handle_poison+0x45/0xc0
memory_failure+0x65e/0xc70
hard_offline_page_store+0x55/0xa0
kernfs_fop_write_iter+0x12c/0x1d0
vfs_write+0x387/0x550
ksys_write+0x64/0xe0
do_syscall_64+0xca/0x1e0
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fc862314887
Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007fff19311268 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007fc862314887
RDX: 000000000000000c RSI: 000056405645fe10 RDI: 0000000000000001
RBP: 000056405645fe10 R08: 00007fc8623d1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007fc86241b780 R14: 00007fc862417600 R15: 00007fc862416a00
In short, below scene breaks the lock dependency chain:
memory_failure
__page_handle_poison
zone_pcp_disable -- lock(pcp_batch_high_lock)
dissolve_free_huge_page
__hugetlb_vmemmap_restore_folio
static_key_slow_dec
cpus_read_lock -- rlock(cpu_hotplug_lock)
Fix this by calling drain_all_pages() instead.
This issue won't occur until commit a6b40850c442 ("mm: hugetlb: replace
hugetlb_free_vmemmap_enabled with a static_key"). As it introduced
rlock(cpu_hotplug_lock) in dissolve_free_huge_page() code path while
lock(pcp_batch_high_lock) is already in the __page_handle_poison().
[linmiaohe@huawei.com: extend comment per Oscar]
[akpm@linux-foundation.org: reflow block comment]
Link: https://lkml.kernel.org/r/20240407085456.2798193-1-linmiaohe@huawei.com
Fixes: a6b40850c442 ("mm: hugetlb: replace hugetlb_free_vmemmap_enabled with a static_key")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
After UFFDIO_POISON, there can be two kinds of hugetlb pte markers, either
the POISON one or UFFD_WP one.
Allow change protection to run on a poisoned marker just like !hugetlb
cases, ignoring the marker irrelevant of the permission.
Here the two bits are mutual exclusive. For example, when install a
poisoned entry it must not be UFFD_WP already (by checking pte_none()
before such install). And it also means if UFFD_WP is set there must have
no POISON bit set. It makes sense because UFFD_WP is a bit to reflect
permission, and permissions do not apply if the pte is poisoned and
destined to sigbus.
So here we simply check uffd_wp bit set first, do nothing otherwise.
Attach the Fixes to UFFDIO_POISON work, as before that it should not be
possible to have poison entry for hugetlb (e.g., hugetlb doesn't do swap,
so no chance of swapin errors).
Link: https://lkml.kernel.org/r/20240405231920.1772199-1-peterx@redhat.com
Link: https://lore.kernel.org/r/000000000000920d5e0615602dd1@google.com
Fixes: fc71884a5f59 ("mm: userfaultfd: add new UFFDIO_POISON ioctl")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: syzbot+b07c8ac8eee3d4d8440f@syzkaller.appspotmail.com
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: <stable@vger.kernel.org> [6.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When seq_* code sees that its buffer overflowed, it re-allocates a bigger
onecand calls seq_operations->start() callback again. stack_start()
naively though that if it got called again, it meant that the old record
got already printed so it returned the next object, but that is not true.
The consequence of that is that every time stack_stop() -> stack_start()
get called because we needed a bigger buffer, stack_start() will skip
entries, and those will not be printed.
Fix it by not advancing to the next object in stack_start().
Link: https://lkml.kernel.org/r/20240404070702.2744-5-osalvador@suse.de
Fixes: 765973a09803 ("mm,page_owner: display all stacks and their count")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Upon migration, new allocated pages are being given the handle of the old
pages. This is problematic because it means that for the stack which
allocated the old page, we will be substracting the old page + the new one
when that page is freed, creating an accounting imbalance.
There is an interest in keeping it that way, as otherwise the output will
biased towards migration stacks should those operations occur often, but
that is not really helpful.
The link from the new page to the old stack is being performed by calling
__update_page_owner_handle() in __folio_copy_owner(). The only thing that
is left is to link the migrate stack to the old page, so the old page will
be subtracted from the migrate stack, avoiding by doing so any possible
imbalance.
Link: https://lkml.kernel.org/r/20240404070702.2744-4-osalvador@suse.de
Fixes: 217b2119b9e2 ("mm,page_owner: implement the tracking of the stacks count")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Current code does not contemplate scenarios were an allocation and free
operation on the same pages do not handle it in the same amount at once.
To give an example, page_alloc_exact(), where we will allocate a page of
enough order to stafisfy the size request, but we will free the remainings
right away.
In the above example, we will increment the stack_record refcount only
once, but we will decrease it the same number of times as number of unused
pages we have to free. This will lead to a warning because of refcount
imbalance.
Fix this by recording the number of base pages in the refcount field.
Link: https://lkml.kernel.org/r/20240404070702.2744-3-osalvador@suse.de
Reported-by: syzbot+41bbfdb8d41003d12c0f@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-mm/00000000000090e8ff0613eda0e5@google.com
Fixes: 217b2119b9e2 ("mm,page_owner: implement the tracking of the stacks count")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "page_owner: Fix refcount imbalance and print fixup", v4.
This series consists of a refactoring/correctness of updating the metadata
of tail pages, a couple of fixups for the refcounting part and a fixup for
the stack_start() function.
From this series on, instead of counting the stacks, we count the
outstanding nr_base_pages each stack has, which gives us a much better
memory overview. The other fixup is for the migration part.
A more detailed explanation can be found in the changelog of the
respective patches.
This patch (of 4):
__set_page_owner_handle() and __reset_page_owner() update the metadata of
all pages when the page is of a higher-order, but we miss to do the same
when the pages are migrated. __folio_copy_owner() only updates the
metadata of the head page, meaning that the information stored in the
first page and the tail pages will not match.
Strictly speaking that is not a big problem because 1) we do not print
tail pages and 2) upon splitting all tail pages will inherit the metadata
of the head page, but it is better to have all metadata in check should
there be any problem, so it can ease debugging.
For that purpose, a couple of helpers are created
__update_page_owner_handle() which updates the metadata on allocation, and
__update_page_owner_free_handle() which does the same when the page is
freed.
__folio_copy_owner() will make use of both as it needs to entirely replace
the page_owner metadata for the new page.
Link: https://lkml.kernel.org/r/20240404070702.2744-1-osalvador@suse.de
Link: https://lkml.kernel.org/r/20240404070702.2744-2-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit d7a08838ab74 ("mm: userfaultfd: fix unexpected change to src_folio
when UFFDIO_MOVE fails") moved the src_folio->{mapping, index} changing to
after clearing the page-table and ensuring that it's not pinned. This
avoids failure of swapout+migration and possibly memory corruption.
However, the commit missed fixing it in the huge-page case.
Link: https://lkml.kernel.org/r/20240404171726.2302435-1-lokeshgidra@google.com
Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI")
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Nicolas Geoffray <ngeoffray@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Darrick reports that in some cases where pread() would fail with -EIO and
mmap()+access would generate a SIGBUS signal, MADV_POPULATE_READ /
MADV_POPULATE_WRITE will keep retrying forever and not fail with -EFAULT.
While the madvise() call can be interrupted by a signal, this is not the
desired behavior. MADV_POPULATE_READ / MADV_POPULATE_WRITE should behave
like page faults in that case: fail and not retry forever.
A reproducer can be found at [1].
The reason is that __get_user_pages(), as called by
faultin_vma_page_range(), will not handle VM_FAULT_RETRY in a proper way:
it will simply return 0 when VM_FAULT_RETRY happened, making
madvise_populate()->faultin_vma_page_range() retry again and again, never
setting FOLL_TRIED->FAULT_FLAG_TRIED for __get_user_pages().
__get_user_pages_locked() does what we want, but duplicating that logic in
faultin_vma_page_range() feels wrong.
So let's use __get_user_pages_locked() instead, that will detect
VM_FAULT_RETRY and set FOLL_TRIED when retrying, making the fault handler
return VM_FAULT_SIGBUS (VM_FAULT_ERROR) at some point, propagating -EFAULT
from faultin_page() to __get_user_pages(), all the way to
madvise_populate().
But, there is an issue: __get_user_pages_locked() will end up re-taking
the MM lock and then __get_user_pages() will do another VMA lookup. In
the meantime, the VMA layout could have changed and we'd fail with
different error codes than we'd want to.
As __get_user_pages() will currently do a new VMA lookup either way, let
it do the VMA handling in a different way, controlled by a new
FOLL_MADV_POPULATE flag, effectively moving these checks from
madvise_populate() + faultin_page_range() in there.
With this change, Darricks reproducer properly fails with -EFAULT, as
documented for MADV_POPULATE_READ / MADV_POPULATE_WRITE.
[1] https://lore.kernel.org/all/20240313171936.GN1927156@frogsfrogsfrogs/
Link: https://lkml.kernel.org/r/20240314161300.382526-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240314161300.382526-2-david@redhat.com
Fixes: 4ca9b3859dac ("mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Darrick J. Wong <djwong@kernel.org>
Closes: https://lore.kernel.org/all/20240311223815.GW1927156@frogsfrogsfrogs/
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Now the __GFP_COMP is set only if the higher-order is not 0. However,
__GFP_COMP flag can be set unconditionally because compound page can
not be created in the order-0 case. And this can also simplify the code
a bit (no need to check the order is 0 or not).
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
|
An identical one exists for vm_insert_page(), add one for
vm_insert_pages() to avoid needing to check for CONFIG_MMU in code using
it.
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
The struct track for every object in a new slab is already set up by
new_slab(), so remove the duplicate initialization in
early_kmem_cache_node_alloc().
Co-developed-by: Hyunmin Lee <hyunminlr@gmail.com>
Signed-off-by: Hyunmin Lee <hyunminlr@gmail.com>
Co-developed-by: Jeungwoo Yoo <casionwoo@gmail.com>
Signed-off-by: Jeungwoo Yoo <casionwoo@gmail.com>
Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
|
There's a bunch of flags that are purely based on what the file
operations support while also never being conditionally set or unset.
IOW, they're not subject to change for individual files. Imho, such
flags don't need to live in f_mode they might as well live in the fops
structs itself. And the fops struct already has that lonely
mmap_supported_flags member. We might as well turn that into a generic
fop_flags member and move a few flags from FMODE_* space into FOP_*
space. That gets us four FMODE_* bits back and the ability for new
static flags that are about file ops to not have to live in FMODE_*
space but in their own FOP_* space. It's not the most beautiful thing
ever but it gets the job done. Yes, there'll be an additional pointer
chase but hopefully that won't matter for these flags.
I suspect there's a few more we can move into there and that we can also
redirect a bunch of new flag suggestions that follow this pattern into
the fop_flags field instead of f_mode.
Link: https://lore.kernel.org/r/20240328-gewendet-spargel-aa60a030ef74@brauner
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
PAT handling won't do the right thing in COW mappings: the first PTE (or,
in fact, all PTEs) can be replaced during write faults to point at anon
folios. Reliably recovering the correct PFN and cachemode using
follow_phys() from PTEs will not work in COW mappings.
Using follow_phys(), we might just get the address+protection of the anon
folio (which is very wrong), or fail on swap/nonswap entries, failing
follow_phys() and triggering a WARN_ON_ONCE() in untrack_pfn() and
track_pfn_copy(), not properly calling free_pfn_range().
In free_pfn_range(), we either wouldn't call memtype_free() or would call
it with the wrong range, possibly leaking memory.
To fix that, let's update follow_phys() to refuse returning anon folios,
and fallback to using the stored PFN inside vma->vm_pgoff for COW mappings
if we run into that.
We will now properly handle untrack_pfn() with COW mappings, where we
don't need the cachemode. We'll have to fail fork()->track_pfn_copy() if
the first page was replaced by an anon folio, though: we'd have to store
the cachemode in the VMA to make this work, likely growing the VMA size.
For now, lets keep it simple and let track_pfn_copy() just fail in that
case: it would have failed in the past with swap/nonswap entries already,
and it would have done the wrong thing with anon folios.
Simple reproducer to trigger the WARN_ON_ONCE() in untrack_pfn():
<--- C reproducer --->
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <liburing.h>
int main(void)
{
struct io_uring_params p = {};
int ring_fd;
size_t size;
char *map;
ring_fd = io_uring_setup(1, &p);
if (ring_fd < 0) {
perror("io_uring_setup");
return 1;
}
size = p.sq_off.array + p.sq_entries * sizeof(unsigned);
/* Map the submission queue ring MAP_PRIVATE */
map = mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
ring_fd, IORING_OFF_SQ_RING);
if (map == MAP_FAILED) {
perror("mmap");
return 1;
}
/* We have at least one page. Let's COW it. */
*map = 0;
pause();
return 0;
}
<--- C reproducer --->
On a system with 16 GiB RAM and swap configured:
# ./iouring &
# memhog 16G
# killall iouring
[ 301.552930] ------------[ cut here ]------------
[ 301.553285] WARNING: CPU: 7 PID: 1402 at arch/x86/mm/pat/memtype.c:1060 untrack_pfn+0xf4/0x100
[ 301.553989] Modules linked in: binfmt_misc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_g
[ 301.558232] CPU: 7 PID: 1402 Comm: iouring Not tainted 6.7.5-100.fc38.x86_64 #1
[ 301.558772] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebu4
[ 301.559569] RIP: 0010:untrack_pfn+0xf4/0x100
[ 301.559893] Code: 75 c4 eb cf 48 8b 43 10 8b a8 e8 00 00 00 3b 6b 28 74 b8 48 8b 7b 30 e8 ea 1a f7 000
[ 301.561189] RSP: 0018:ffffba2c0377fab8 EFLAGS: 00010282
[ 301.561590] RAX: 00000000ffffffea RBX: ffff9208c8ce9cc0 RCX: 000000010455e047
[ 301.562105] RDX: 07fffffff0eb1e0a RSI: 0000000000000000 RDI: ffff9208c391d200
[ 301.562628] RBP: 0000000000000000 R08: ffffba2c0377fab8 R09: 0000000000000000
[ 301.563145] R10: ffff9208d2292d50 R11: 0000000000000002 R12: 00007fea890e0000
[ 301.563669] R13: 0000000000000000 R14: ffffba2c0377fc08 R15: 0000000000000000
[ 301.564186] FS: 0000000000000000(0000) GS:ffff920c2fbc0000(0000) knlGS:0000000000000000
[ 301.564773] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 301.565197] CR2: 00007fea88ee8a20 CR3: 00000001033a8000 CR4: 0000000000750ef0
[ 301.565725] PKRU: 55555554
[ 301.565944] Call Trace:
[ 301.566148] <TASK>
[ 301.566325] ? untrack_pfn+0xf4/0x100
[ 301.566618] ? __warn+0x81/0x130
[ 301.566876] ? untrack_pfn+0xf4/0x100
[ 301.567163] ? report_bug+0x171/0x1a0
[ 301.567466] ? handle_bug+0x3c/0x80
[ 301.567743] ? exc_invalid_op+0x17/0x70
[ 301.568038] ? asm_exc_invalid_op+0x1a/0x20
[ 301.568363] ? untrack_pfn+0xf4/0x100
[ 301.568660] ? untrack_pfn+0x65/0x100
[ 301.568947] unmap_single_vma+0xa6/0xe0
[ 301.569247] unmap_vmas+0xb5/0x190
[ 301.569532] exit_mmap+0xec/0x340
[ 301.569801] __mmput+0x3e/0x130
[ 301.570051] do_exit+0x305/0xaf0
...
Link: https://lkml.kernel.org/r/20240403212131.929421-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Wupeng Ma <mawupeng1@huawei.com>
Closes: https://lkml.kernel.org/r/20240227122814.3781907-1-mawupeng1@huawei.com
Fixes: b1a86e15dc03 ("x86, pat: remove the dependency on 'vm_pgoff' in track/untrack pfn vma routines")
Fixes: 5899329b1910 ("x86: PAT: implement track/untrack of pfnmap regions for x86 - v3")
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
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>
|
|
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>
|
|
slab_alloc_node() should be __slab_alloc_node().
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
|
The break conditions for filling cpu partial can be more readable and
simple.
If slub_get_cpu_partial() returns 0, we can confirm that we don't need
to fill cpu partial, then we should break from the loop. On the other
hand, we also should break from the loop if we have added enough cpu
partial slabs.
Meanwhile, the logic above gets rid of the #ifdef and also fixes a weird
corner case that if we set cpu_partial_slabs to 0 from sysfs, we still
allocate at least one here.
Signed-off-by: Xiongwei Song <xiongwei.song@windriver.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
|
Add slub_get_cpu_partial() and dummy function to help improve
get_partial_node(). It can help remove #ifdef of CONFIG_SLUB_CPU_PARTIAL
and improve filling cpu partial logic.
Signed-off-by: Xiongwei Song <xiongwei.song@windriver.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
|
The check of !kmem_cache_has_cpu_partial(s) with
CONFIG_SLUB_CPU_PARTIAL enabled here is always false.
We have already checked kmem_cache_debug() earlier and if it was true,
then we either continued or broke from the loop so we can't reach this
code in that case and don't need to check kmem_cache_debug() as part of
kmem_cache_has_cpu_partial() again. Here we can remove it.
Signed-off-by: Xiongwei Song <xiongwei.song@windriver.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
