Allocate post-processing target in place_pp_slot(). This simplifies
scan_slots_for_writeback() and scan_slots_for_recompress() loops because
we don't need to track pps pointer state anymore. Previously we have to
explicitly NULL the point if it has been added to a post-processing bucket
or re-use previously allocated pointer otherwise and make sure we don't
leak the memory in the end.
We are also fine doing GFP_NOIO allocation, as post-processing can be
called under memory pressure so we better pick as many slots as we can as
soon as we can and start post-processing them, possibly saving the memory.
Allocation failure there is not fatal, we will post-process whatever we
put into the buckets on previous iterations.
Link: https://lkml.kernel.org/r/20250303022425.285971-12-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This reworks recompression loop handling:
- set a rule that stream-put NULLs the stream pointer If the loop
returns with a non-NULL stream then it's a successful recompression,
otherwise the stream should always be NULL.
- do not count the number of recompressions Mark object as
incompressible as soon as the algorithm with the highest priority failed
to compress that object.
- count compression errors as resource usage Even if compression has
failed, we still need to bump num_recomp_pages counter.
Link: https://lkml.kernel.org/r/20250303022425.285971-11-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Previously zram write() was atomic which required us to pass
__GFP_KSWAPD_RECLAIM to zsmalloc handle allocation on a fast path and
attempt a slow path allocation (with recompression) if the fast path
failed.
Since we are not in atomic context anymore we can permit direct reclaim
during handle allocation, and hence can have a single allocation path.
There is no slow path anymore so we don't unlock per-CPU stream (and don't
lose compressed data) which means that there is no need to do
recompression now (which should reduce CPU and battery usage).
Link: https://lkml.kernel.org/r/20250303022425.285971-6-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently, per-CPU stream access is done from a non-preemptible (atomic)
section, which imposes the same atomicity requirements on compression
backends as entry spin-lock, and makes it impossible to use algorithms
that can schedule/wait/sleep during compression and decompression.
Switch to preemptible per-CPU model, similar to the one used in zswap.
Instead of a per-CPU local lock, each stream carries a mutex which is
locked throughout entire time zram uses it for compression or
decompression, so that cpu-dead event waits for zram to stop using a
particular per-CPU stream and release it.
Link: https://lkml.kernel.org/r/20250303022425.285971-3-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Suggested-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "zsmalloc/zram: there be preemption", v10.
Currently zram runs compression and decompression in non-preemptible
sections, e.g.
zcomp_stream_get() // grabs CPU local lock
zcomp_compress()
or
zram_slot_lock() // grabs entry spin-lock
zcomp_stream_get() // grabs CPU local lock
zs_map_object() // grabs rwlock and CPU local lock
zcomp_decompress()
Potentially a little troublesome for a number of reasons.
For instance, this makes it impossible to use async compression algorithms
or/and H/W compression algorithms, which can wait for OP completion or
resource availability. This also restricts what compression algorithms
can do internally, for example, zstd can allocate internal state memory
for C/D dictionaries:
do_fsync()
do_writepages()
zram_bio_write()
zram_write_page() // become non-preemptible
zcomp_compress()
zstd_compress()
ZSTD_compress_usingCDict()
ZSTD_compressBegin_usingCDict_internal()
ZSTD_resetCCtx_usingCDict()
ZSTD_resetCCtx_internal()
zstd_custom_alloc() // memory allocation
Not to mention that the system can be configured to maximize compression
ratio at a cost of CPU/HW time (e.g. lz4hc or deflate with very high
compression level) so zram can stay in non-preemptible section (even under
spin-lock or/and rwlock) for an extended period of time. Aside from
compression algorithms, this also restricts what zram can do. One
particular example is zram_write_page() zsmalloc handle allocation, which
has an optimistic allocation (disallowing direct reclaim) and a
pessimistic fallback path, which then forces zram to compress the page one
more time.
This series changes zram to not directly impose atomicity restrictions on
compression algorithms (and on itself), which makes zram write() fully
preemptible; zram read(), sadly, is not always preemptible yet. There are
still indirect atomicity restrictions imposed by zsmalloc(). One notable
example is object mapping API, which returns with: a) local CPU lock held
b) zspage rwlock held
First, zsmalloc's zspage lock is converted from rwlock to a special type
of RW-lookalike look with some extra guarantees/features. Second, a new
handle mapping is introduced which doesn't use per-CPU buffers (and hence
no local CPU lock), does fewer memcpy() calls, but requires users to
provide a pointer to temp buffer for object copy-in (when needed). Third,
zram is converted to the new zsmalloc mapping API and thus zram read()
becomes preemptible.
This patch (of 19):
Concurrent modifications of meta table entries is now handled by per-entry
spin-lock. This has a number of shortcomings.
First, this imposes atomic requirements on compression backends. zram can
call both zcomp_compress() and zcomp_decompress() under entry spin-lock,
which implies that we can use only compression algorithms that don't
schedule/sleep/wait during compression and decompression. This, for
instance, makes it impossible to use some of the ASYNC compression
algorithms (H/W compression, etc.) implementations.
Second, this can potentially trigger watchdogs. For example, entry
re-compression with secondary algorithms is performed under entry
spin-lock. Given that we chain secondary compression algorithms and that
some of them can be configured for best compression ratio (and worst
compression speed) zram can stay under spin-lock for quite some time.
Having a per-entry mutex (or, for instance, a rw-semaphore) significantly
increases sizeof() of each entry and hence the meta table. Therefore
entry locking returns back to bit locking, as before, however, this time
also preempt-rt friendly, because if waits-on-bit instead of
spinning-on-bit. Lock owners are also now permitted to schedule, which is
a first step on the path of making zram non-atomic.
Link: https://lkml.kernel.org/r/20250303022425.285971-1-senozhatsky@chromium.org
Link: https://lkml.kernel.org/r/20250303022425.285971-2-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull block fixes from Jens Axboe:
- NVMe pull request via Keith:
- TCP use after free fix on polling (Sagi)
- Controller memory buffer cleanup fixes (Icenowy)
- Free leaking requests on bad user passthrough commands (Keith)
- TCP error message fix (Maurizio)
- TCP corruption fix on partial PDU (Maurizio)
- TCP memory ordering fix for weakly ordered archs (Meir)
- Type coercion fix on message error for TCP (Dan)
- Name the RQF flags enum, fixing issues with anon enums and BPF import
of it
- ublk parameter setting fix
- GPT partition 7-bit conversion fix
* tag 'block-6.14-20250306' of git://git.kernel.dk/linux:
block: Name the RQF flags enum
nvme-tcp: fix signedness bug in nvme_tcp_init_connection()
block: fix conversion of GPT partition name to 7-bit
ublk: set_params: properly check if parameters can be applied
nvmet-tcp: Fix a possible sporadic response drops in weakly ordered arch
nvme-tcp: fix potential memory corruption in nvme_tcp_recv_pdu()
nvme-tcp: Fix a C2HTermReq error message
nvmet: remove old function prototype
nvme-ioctl: fix leaked requests on mapping error
nvme-pci: skip CMB blocks incompatible with PCI P2P DMA
nvme-pci: clean up CMBMSC when registering CMB fails
nvme-tcp: fix possible UAF in nvme_tcp_poll
The parameters set by the set_params call are only applied to the block
device in the start_dev call. So if a device has already been started, a
subsequently issued set_params on that device will not have the desired
effect, and should return an error. There is an existing check for this
- set_params fails on devices in the LIVE state. But this check is not
sufficient to cover the recovery case. In this case, the device will be
in the QUIESCED or FAIL_IO states, so set_params will succeed. But this
success is misleading, because the parameters will not be applied, since
the device has already been started (by a previous ublk server). The bit
UB_STATE_USED is set on completion of the start_dev; use it to detect
and fail set_params commands which arrive too late to be applied (after
start_dev).
Signed-off-by: Uday Shankar <ushankar@purestorage.com>
Fixes: 0aa73170eb ("ublk_drv: add SET_PARAMS/GET_PARAMS control command")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250304-set_params-v1-1-17b5e0887606@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block fixes from Jens Axboe:
- MD pull request via Song:
- fix an error handling path for md-linear
- NVMe pull request via Keith:
- Connection fixes for fibre channel transport (Daniel)
- Endian fixes (Keith, Christoph)
- Cleanup fix for host memory buffer (Francis)
- Platform specific power quirks (Georg)
- Target memory leak (Sagi)
- Use appropriate controller state accessor (Daniel)
- Fixup for a regression introduced last week, where sunvdc wasn't
updated for an API change, causing compilation failures on sparc64.
* tag 'block-6.14-20250207' of git://git.kernel.dk/linux:
drivers/block/sunvdc.c: update the correct AIP call
md: Fix linear_set_limits()
nvme-fc: use ctrl state getter
nvme: make nvme_tls_attrs_group static
nvmet: add a missing endianess conversion in nvmet_execute_admin_connect
nvmet: the result field in nvmet_alloc_ctrl_args is little endian
nvmet: fix a memory leak in controller identify
nvme-fc: do not ignore connectivity loss during connecting
nvme: handle connectivity loss in nvme_set_queue_count
nvme-fc: go straight to connecting state when initializing
nvme-pci: Add TUXEDO IBP Gen9 to Samsung sleep quirk
nvme-pci: Add TUXEDO InfinityFlex to Samsung sleep quirk
nvme-pci: remove redundant dma frees in hmb
nvmet: fix rw control endian access
My sparc64 defconfig build failed like this:
drivers/block/sunvdc.c: In function 'vdc_queue_drain':
drivers/block/sunvdc.c:1130:9: error: too many arguments to function 'blk_mq_unquiesce_queue'
1130 | blk_mq_unquiesce_queue(q, memflags);
| ^~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/block/sunvdc.c:10:
include/linux/blk-mq.h:895:6: note: declared here
895 | void blk_mq_unquiesce_queue(struct request_queue *q);
| ^~~~~~~~~~~~~~~~~~~~~~
drivers/block/sunvdc.c:1131:9: error: too few arguments to function 'blk_mq_unfreeze_queue'
1131 | blk_mq_unfreeze_queue(q);
| ^~~~~~~~~~~~~~~~~~~~~
In file included from drivers/block/sunvdc.c:10:
include/linux/blk-mq.h:914:1: note: declared here
914 | blk_mq_unfreeze_queue(struct request_queue *q, unsigned int memflags)
| ^~~~~~~~~~~~~~~~~~~~~
Fixes: 1e1a9cecfa ("block: force noio scope in blk_mq_freeze_queue")
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull more block updates from Jens Axboe:
- MD pull request via Song:
- Fix a md-cluster regression introduced
- More sysfs race fixes
- Mark anything inside queue freezing as not being able to do IO for
memory allocations
- Fix for a regression introduced in loop in this merge window
- Fix for a regression in queue mapping setups introduced in this merge
window
- Fix for the block dio fops attempting an iov_iter revert upton
getting -EIOCBQUEUED on the read side. This one is going to stable as
well
* tag 'block-6.14-20250131' of git://git.kernel.dk/linux:
block: force noio scope in blk_mq_freeze_queue
block: fix nr_hw_queue update racing with disk addition/removal
block: get rid of request queue ->sysfs_dir_lock
loop: don't clear LO_FLAGS_PARTSCAN on LOOP_SET_STATUS{,64}
md/md-bitmap: Synchronize bitmap_get_stats() with bitmap lifetime
blk-mq: create correct map for fallback case
block: don't revert iter for -EIOCBQUEUED
When block drivers or the core block code perform allocations with a
frozen queue, this could try to recurse into the block device to
reclaim memory and deadlock. Thus all allocations done by a process
that froze a queue need to be done without __GFP_IO and __GFP_FS.
Instead of tying to track all of them down, force a noio scope as
part of freezing the queue.
Note that nvme is a bit of a mess here due to the non-owner freezes,
and they will be addressed separately.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250131120352.1315351-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull driver core and debugfs updates from Greg KH:
"Here is the big set of driver core and debugfs updates for 6.14-rc1.
Included in here is a bunch of driver core, PCI, OF, and platform rust
bindings (all acked by the different subsystem maintainers), hence the
merge conflict with the rust tree, and some driver core api updates to
mark things as const, which will also require some fixups due to new
stuff coming in through other trees in this merge window.
There are also a bunch of debugfs updates from Al, and there is at
least one user that does have a regression with these, but Al is
working on tracking down the fix for it. In my use (and everyone
else's linux-next use), it does not seem like a big issue at the
moment.
Here's a short list of the things in here:
- driver core rust bindings for PCI, platform, OF, and some i/o
functions.
We are almost at the "write a real driver in rust" stage now,
depending on what you want to do.
- misc device rust bindings and a sample driver to show how to use
them
- debugfs cleanups in the fs as well as the users of the fs api for
places where drivers got it wrong or were unnecessarily doing
things in complex ways.
- driver core const work, making more of the api take const * for
different parameters to make the rust bindings easier overall.
- other small fixes and updates
All of these have been in linux-next with all of the aforementioned
merge conflicts, and the one debugfs issue, which looks to be resolved
"soon""
* tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits)
rust: device: Use as_char_ptr() to avoid explicit cast
rust: device: Replace CString with CStr in property_present()
devcoredump: Constify 'struct bin_attribute'
devcoredump: Define 'struct bin_attribute' through macro
rust: device: Add property_present()
saner replacement for debugfs_rename()
orangefs-debugfs: don't mess with ->d_name
octeontx2: don't mess with ->d_parent or ->d_parent->d_name
arm_scmi: don't mess with ->d_parent->d_name
slub: don't mess with ->d_name
sof-client-ipc-flood-test: don't mess with ->d_name
qat: don't mess with ->d_name
xhci: don't mess with ->d_iname
mtu3: don't mess wiht ->d_iname
greybus/camera - stop messing with ->d_iname
mediatek: stop messing with ->d_iname
netdevsim: don't embed file_operations into your structs
b43legacy: make use of debugfs_get_aux()
b43: stop embedding struct file_operations into their objects
carl9170: stop embedding file_operations into their objects
...
Pull virtio updates from Michael Tsirkin:
"A small number of improvements all over the place:
- vdpa/octeon support for multiple interrupts
- virtio-pci support for error recovery
- vp_vdpa support for notification with data
- vhost/net fix to set num_buffers for spec compliance
- virtio-mem now works with kdump on s390
And small cleanups all over the place"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (23 commits)
virtio_blk: Add support for transport error recovery
virtio_pci: Add support for PCIe Function Level Reset
vhost/net: Set num_buffers for virtio 1.0
vdpa/octeon_ep: read vendor-specific PCI capability
virtio-pci: define type and header for PCI vendor data
vdpa/octeon_ep: handle device config change events
vdpa/octeon_ep: enable support for multiple interrupts per device
vdpa: solidrun: Replace deprecated PCI functions
s390/kdump: virtio-mem kdump support (CONFIG_PROC_VMCORE_DEVICE_RAM)
virtio-mem: support CONFIG_PROC_VMCORE_DEVICE_RAM
virtio-mem: remember usable region size
virtio-mem: mark device ready before registering callbacks in kdump mode
fs/proc/vmcore: introduce PROC_VMCORE_DEVICE_RAM to detect device RAM ranges in 2nd kernel
fs/proc/vmcore: factor out freeing a list of vmcore ranges
fs/proc/vmcore: factor out allocating a vmcore range and adding it to a list
fs/proc/vmcore: move vmcore definitions out of kcore.h
fs/proc/vmcore: prefix all pr_* with "vmcore:"
fs/proc/vmcore: disallow vmcore modifications while the vmcore is open
fs/proc/vmcore: replace vmcoredd_mutex by vmcore_mutex
fs/proc/vmcore: convert vmcore_cb_lock into vmcore_mutex
...
LOOP_SET_STATUS{,64} can set a lot more flags than it is supposed to
clear (the LOOP_SET_STATUS_CLEARABLE_FLAGS vs
LOOP_SET_STATUS_SETTABLE_FLAGS defines should have been a hint..).
Fix this by only clearing the bits in LOOP_SET_STATUS_CLEARABLE_FLAGS.
Fixes: ae074d07a0 ("loop: move updating lo_flag s out of loop_set_status_from_info")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250127143045.538279-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add support for proper cleanup and re-initialization of virtio-blk devices
during transport reset error recovery flow.
This enhancement includes:
- Pre-reset handler (reset_prepare) to perform device-specific cleanup
- Post-reset handler (reset_done) to re-initialize the device
These changes allow the device to recover from various reset scenarios,
ensuring proper functionality after a reset event occurs.
Without this implementation, the device cannot properly recover from
resets, potentially leading to undefined behavior or device malfunction.
This feature has been tested using PCI transport with Function Level
Reset (FLR) as an example reset mechanism. The reset can be triggered
manually via sysfs (echo 1 > /sys/bus/pci/devices/$PCI_ADDR/reset).
Signed-off-by: Israel Rukshin <israelr@nvidia.com>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Message-Id: <1732690652-3065-3-git-send-email-israelr@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Pull MM updates from Andrew Morton:
"The various patchsets are summarized below. Plus of course many
indivudual patches which are described in their changelogs.
- "Allocate and free frozen pages" from Matthew Wilcox reorganizes
the page allocator so we end up with the ability to allocate and
free zero-refcount pages. So that callers (ie, slab) can avoid a
refcount inc & dec
- "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
use large folios other than PMD-sized ones
- "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
and fixes for this small built-in kernel selftest
- "mas_anode_descend() related cleanup" from Wei Yang tidies up part
of the mapletree code
- "mm: fix format issues and param types" from Keren Sun implements a
few minor code cleanups
- "simplify split calculation" from Wei Yang provides a few fixes and
a test for the mapletree code
- "mm/vma: make more mmap logic userland testable" from Lorenzo
Stoakes continues the work of moving vma-related code into the
(relatively) new mm/vma.c
- "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
Hildenbrand cleans up and rationalizes handling of gfp flags in the
page allocator
- "readahead: Reintroduce fix for improper RA window sizing" from Jan
Kara is a second attempt at fixing a readahead window sizing issue.
It should reduce the amount of unnecessary reading
- "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
addresses an issue where "huge" amounts of pte pagetables are
accumulated:
https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/
Qi's series addresses this windup by synchronously freeing PTE
memory within the context of madvise(MADV_DONTNEED)
- "selftest/mm: Remove warnings found by adding compiler flags" from
Muhammad Usama Anjum fixes some build warnings in the selftests
code when optional compiler warnings are enabled
- "mm: don't use __GFP_HARDWALL when migrating remote pages" from
David Hildenbrand tightens the allocator's observance of
__GFP_HARDWALL
- "pkeys kselftests improvements" from Kevin Brodsky implements
various fixes and cleanups in the MM selftests code, mainly
pertaining to the pkeys tests
- "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
estimate application working set size
- "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
provides some cleanups to memcg's hugetlb charging logic
- "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
removes the global swap cgroup lock. A speedup of 10% for a
tmpfs-based kernel build was demonstrated
- "zram: split page type read/write handling" from Sergey Senozhatsky
has several fixes and cleaups for zram in the area of
zram_write_page(). A watchdog softlockup warning was eliminated
- "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
Brodsky cleans up the pagetable destructor implementations. A rare
use-after-free race is fixed
- "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
simplifies and cleans up the debugging code in the VMA merging
logic
- "Account page tables at all levels" from Kevin Brodsky cleans up
and regularizes the pagetable ctor/dtor handling. This results in
improvements in accounting accuracy
- "mm/damon: replace most damon_callback usages in sysfs with new
core functions" from SeongJae Park cleans up and generalizes
DAMON's sysfs file interface logic
- "mm/damon: enable page level properties based monitoring" from
SeongJae Park increases the amount of information which is
presented in response to DAMOS actions
- "mm/damon: remove DAMON debugfs interface" from SeongJae Park
removes DAMON's long-deprecated debugfs interfaces. Thus the
migration to sysfs is completed
- "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
Peter Xu cleans up and generalizes the hugetlb reservation
accounting
- "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
removes a never-used feature of the alloc_pages_bulk() interface
- "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
extends DAMOS filters to support not only exclusion (rejecting),
but also inclusion (allowing) behavior
- "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
introduces a new memory descriptor for zswap.zpool that currently
overlaps with struct page for now. This is part of the effort to
reduce the size of struct page and to enable dynamic allocation of
memory descriptors
- "mm, swap: rework of swap allocator locks" from Kairui Song redoes
and simplifies the swap allocator locking. A speedup of 400% was
demonstrated for one workload. As was a 35% reduction for kernel
build time with swap-on-zram
- "mm: update mips to use do_mmap(), make mmap_region() internal"
from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
mmap_region() can be made MM-internal
- "mm/mglru: performance optimizations" from Yu Zhao fixes a few
MGLRU regressions and otherwise improves MGLRU performance
- "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
Park updates DAMON documentation
- "Cleanup for memfd_create()" from Isaac Manjarres does that thing
- "mm: hugetlb+THP folio and migration cleanups" from David
Hildenbrand provides various cleanups in the areas of hugetlb
folios, THP folios and migration
- "Uncached buffered IO" from Jens Axboe implements the new
RWF_DONTCACHE flag which provides synchronous dropbehind for
pagecache reading and writing. To permite userspace to address
issues with massive buildup of useless pagecache when
reading/writing fast devices
- "selftests/mm: virtual_address_range: Reduce memory" from Thomas
Weißschuh fixes and optimizes some of the MM selftests"
* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
mm/compaction: fix UBSAN shift-out-of-bounds warning
s390/mm: add missing ctor/dtor on page table upgrade
kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
tools: add VM_WARN_ON_VMG definition
mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
seqlock: add missing parameter documentation for raw_seqcount_try_begin()
mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
mm/page_alloc: remove the incorrect and misleading comment
zram: remove zcomp_stream_put() from write_incompressible_page()
mm: separate move/undo parts from migrate_pages_batch()
mm/kfence: use str_write_read() helper in get_access_type()
selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
selftests/mm: vm_util: split up /proc/self/smaps parsing
selftests/mm: virtual_address_range: unmap chunks after validation
selftests/mm: virtual_address_range: mmap() without PROT_WRITE
selftests/memfd/memfd_test: fix possible NULL pointer dereference
mm: add FGP_DONTCACHE folio creation flag
mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
...
Pull non-MM updates from Andrew Morton:
"Mainly individually changelogged singleton patches. The patch series
in this pull are:
- "lib min_heap: Improve min_heap safety, testing, and documentation"
from Kuan-Wei Chiu provides various tightenings to the min_heap
library code
- "xarray: extract __xa_cmpxchg_raw" from Tamir Duberstein preforms
some cleanup and Rust preparation in the xarray library code
- "Update reference to include/asm-<arch>" from Geert Uytterhoeven
fixes pathnames in some code comments
- "Converge on using secs_to_jiffies()" from Easwar Hariharan uses
the new secs_to_jiffies() in various places where that is
appropriate
- "ocfs2, dlmfs: convert to the new mount API" from Eric Sandeen
switches two filesystems to the new mount API
- "Convert ocfs2 to use folios" from Matthew Wilcox does that
- "Remove get_task_comm() and print task comm directly" from Yafang
Shao removes now-unneeded calls to get_task_comm() in various
places
- "squashfs: reduce memory usage and update docs" from Phillip
Lougher implements some memory savings in squashfs and performs
some maintainability work
- "lib: clarify comparison function requirements" from Kuan-Wei Chiu
tightens the sort code's behaviour and adds some maintenance work
- "nilfs2: protect busy buffer heads from being force-cleared" from
Ryusuke Konishi fixes an issues in nlifs when the fs is presented
with a corrupted image
- "nilfs2: fix kernel-doc comments for function return values" from
Ryusuke Konishi fixes some nilfs kerneldoc
- "nilfs2: fix issues with rename operations" from Ryusuke Konishi
addresses some nilfs BUG_ONs which syzbot was able to trigger
- "minmax.h: Cleanups and minor optimisations" from David Laight does
some maintenance work on the min/max library code
- "Fixes and cleanups to xarray" from Kemeng Shi does maintenance
work on the xarray library code"
* tag 'mm-nonmm-stable-2025-01-24-23-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (131 commits)
ocfs2: use str_yes_no() and str_no_yes() helper functions
include/linux/lz4.h: add some missing macros
Xarray: use xa_mark_t in xas_squash_marks() to keep code consistent
Xarray: remove repeat check in xas_squash_marks()
Xarray: distinguish large entries correctly in xas_split_alloc()
Xarray: move forward index correctly in xas_pause()
Xarray: do not return sibling entries from xas_find_marked()
ipc/util.c: complete the kernel-doc function descriptions
gcov: clang: use correct function param names
latencytop: use correct kernel-doc format for func params
minmax.h: remove some #defines that are only expanded once
minmax.h: simplify the variants of clamp()
minmax.h: move all the clamp() definitions after the min/max() ones
minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()
minmax.h: reduce the #define expansion of min(), max() and clamp()
minmax.h: update some comments
minmax.h: add whitespace around operators and after commas
nilfs2: do not update mtime of renamed directory that is not moved
nilfs2: handle errors that nilfs_prepare_chunk() may return
CREDITS: fix spelling mistake
...
zram writeback is a costly operation, because every target slot (unless
ZRAM_HUGE) is decompressed before it gets written to a backing device.
The writeback to a backing device uses submit_bio_wait() which may look
like a rescheduling point. However, if the backing device has
BD_HAS_SUBMIT_BIO bit set __submit_bio() calls directly
disk->fops->submit_bio(bio) on the backing device and so when
submit_bio_wait() calls blk_wait_io() the I/O is already done. On such
systems we effective end up in a loop
for_each (target slot) {
decompress(slot)
__submit_bio()
disk->fops->submit_bio(bio)
}
Which on PREEMPT_NONE systems triggers watchdogs (since there are no
explicit rescheduling points). Add cond_resched() to the zram writeback
loop.
Link: https://lkml.kernel.org/r/20241218063513.297475-8-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We only can read pages from zspool in writeback, zram_read_page() is not
really right in that context not only because it's a more generic function
that handles ZRAM_WB pages, but also because it requires us to unlock slot
between slot flag check and actual page read. Use zram_read_from_zspool()
instead and do slot flags check and page read under the same slot lock.
Link: https://lkml.kernel.org/r/20241218063513.297475-7-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
zram_write_page() handles: ZRAM_SAME pages (which was already factored
out) stores, regular page stores and ZRAM_HUGE pages stores.
ZRAM_HUGE handling adds a significant amount of complexity. Instead, we
can handle ZRAM_HUGE in a separate function. This allows us to simplify
zs_handle allocations slow-path, as it now does not handle ZRAM_HUGE case.
ZRAM_HUGE zs_handle allocation, on the other hand, can now drop
__GFP_KSWAPD_RECLAIM because we handle ZRAM_HUGE in preemptible context
(outside of local-lock scope).
Link: https://lkml.kernel.org/r/20241218063513.297475-5-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Handling of ZRAM_SAME now uses a goto to the final stages of
zram_write_page() plus it introduces a branch and flags variable, which is
not making the code any simpler. In reality, we can handle ZRAM_SAME
immediately when we detect such pages and remove a goto and a branch.
Factor out ZRAM_SAME handling into a separate routine to simplify
zram_write_page().
Link: https://lkml.kernel.org/r/20241218063513.297475-4-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "zram: split page type read/write handling", v2.
This is a subset of [1] series which contains only fixes and improvements
(no new features, as ZRAM_HUGE split is still under consideration).
The motivation for factoring out is that zram_write_page() gets more and
more complex all the time, because it tries to handle too many scenarios:
ZRAM_SAME store, ZRAM_HUGE store, compress page store with zs_malloc
allocation slowpath and conditional recompression, etc. Factor those out
and make things easier to handle.
Addition of cond_resched() is simply a fix, I can trigger watchdog from
zram writeback(). And early slot free is just a reasonable thing to do.
[1] https://lore.kernel.org/linux-kernel/20241119072057.3440039-1-senozhatsky@chromium.org
This patch (of 7):
In the current implementation entry's previously allocated memory is
released in the very last moment, when we already have allocated a new
memory for new data. This, basically, temporarily increases memory usage
for no good reason. For example, consider the case when both old (stale)
and new entry data are incompressible so such entry will temporarily use
two physical pages - one for stale (old) data and one for new data. We
can release old memory as soon as we get a write request for entry.
Link: https://lkml.kernel.org/r/20241218063513.297475-1-senozhatsky@chromium.org
Link: https://lkml.kernel.org/r/20241218063513.297475-2-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull block updates from Jens Axboe:
- NVMe pull requests via Keith:
- Target support for PCI-Endpoint transport (Damien)
- TCP IO queue spreading fixes (Sagi, Chaitanya)
- Target handling for "limited retry" flags (Guixen)
- Poll type fix (Yongsoo)
- Xarray storage error handling (Keisuke)
- Host memory buffer free size fix on error (Francis)
- MD pull requests via Song:
- Reintroduce md-linear (Yu Kuai)
- md-bitmap refactor and fix (Yu Kuai)
- Replace kmap_atomic with kmap_local_page (David Reaver)
- Quite a few queue freeze and debugfs deadlock fixes
Ming introduced lockdep support for this in the 6.13 kernel, and it
has (unsurprisingly) uncovered quite a few issues
- Use const attributes for IO schedulers
- Remove bio ioprio wrappers
- Fixes for stacked device atomic write support
- Refactor queue affinity helpers, in preparation for better supporting
isolated CPUs
- Cleanups of loop O_DIRECT handling
- Cleanup of BLK_MQ_F_* flags
- Add rotational support for null_blk
- Various fixes and cleanups
* tag 'for-6.14/block-20250118' of git://git.kernel.dk/linux: (106 commits)
block: Don't trim an atomic write
block: Add common atomic writes enable flag
md/md-linear: Fix a NULL vs IS_ERR() bug in linear_add()
block: limit disk max sectors to (LLONG_MAX >> 9)
block: Change blk_stack_atomic_writes_limits() unit_min check
block: Ensure start sector is aligned for stacking atomic writes
blk-mq: Move more error handling into blk_mq_submit_bio()
block: Reorder the request allocation code in blk_mq_submit_bio()
nvme: fix bogus kzalloc() return check in nvme_init_effects_log()
md/md-bitmap: move bitmap_{start, end}write to md upper layer
md/raid5: implement pers->bitmap_sector()
md: add a new callback pers->bitmap_sector()
md/md-bitmap: remove the last parameter for bimtap_ops->endwrite()
md/md-bitmap: factor behind write counters out from bitmap_{start/end}write()
md: Replace deprecated kmap_atomic() with kmap_local_page()
md: reintroduce md-linear
partitions: ldm: remove the initial kernel-doc notation
blk-cgroup: rwstat: fix kernel-doc warnings in header file
blk-cgroup: fix kernel-doc warnings in header file
nbd: fix partial sending
...
nbd driver sends request header and payload with multiple call of
sock_sendmsg, and partial sending can't be avoided. However, nbd driver
returns BLK_STS_RESOURCE to block core in this situation. This way causes
one issue: request->tag may change in the next run of nbd_queue_rq(), but
the original old tag has been sent as part of header cookie, this way
confuses nbd driver reply handling, since the real request can't be
retrieved any more with the obsolete old tag.
Fix it by retrying sending directly in per-socket work function,
meantime return BLK_STS_OK to block layer core.
Cc: vincent.chen@sifive.com
Cc: Leon Schuermann <leon@is.currently.online>
Cc: Bart Van Assche <bvanassche@acm.org>
Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Link: https://lore.kernel.org/r/20241029011941.153037-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We need the debugfs / driver-core fixes in here as well for testing and
to build on top of.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All callers of loop_update_dio except for loop_configure already have the
queue frozen, and loop_configure works on an unbound device. Remove the
superfluous recursive freezing in loop_update_dio and add asserts for the
locking and freezing state instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250110073750.1582447-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Unlike all other calls of (__)loop_update_dio, loop_set_status never
looks at the O_DIRECT flag of the backing file, and thus doesn't
re-enable direct I/O on an O_DIRECT backing file if e.g. the new block
size would allow it. Fix that and remove the need for the separate
__loop_update_dio flag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250110073750.1582447-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
loop_set_dio is different from the other (__)loop_update_dio callers in
that it doesn't take any implicit conditions into account and wants to
update the direct I/O flag to the user passed in value and fail if that
can't be done.
Open code the logic here to prepare for simplifying the other direct I/O
flag updates and to make the error handling less convoluted.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250110073750.1582447-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is no point in doing an fdatasync to write out pages when switching
away from direct I/O, as there won't be any. The writeback is only
needed when switching to direct I/O, which would have to invalidate the
pagecache less efficiently from the I/O path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250110073750.1582447-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
While loop_configure simplify assigns the flags passed in by userspace,
loop_set_status only looks at the two changeable flags, and currently
has to do a complicate dance to implement that.
Move assign lo->lo_flags out of loop_set_status_from_info into the
callers and thus drastically simplify the lo_flags handling in
loop_set_status.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250110073750.1582447-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
