As Trond points out [1], the "original time" mentioned in RFC 9754
refers to the timestamps on the files at the time that the delegation
was granted, and not the current timestamp of the file on the server.
Store the current timestamps for the file in the nfs4_delegation when
granting one. Add STATX_ATIME and STATX_MTIME to the request mask in
nfs4_delegation_stat(). When granting OPEN_DELEGATE_READ_ATTRS_DELEG, do
a nfs4_delegation_stat() and save the correct atime. If the stat() fails
for any reason, fall back to granting a normal read deleg.
[1]: https://lore.kernel.org/linux-nfs/47a4e40310e797f21b5137e847b06bb203d99e66.camel@kernel.org/
Fixes: 7e13f4f8d2 ("nfsd: handle delegated timestamps in SETATTR")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Ensure that notify_change() doesn't clobber a delegated ctime update
with current_time() by setting ATTR_CTIME_SET for those updates.
Don't bother setting the timestamps in cb_getattr_update_times() in the
non-delegated case. notify_change() will do that itself.
Fixes: 7e13f4f8d2 ("nfsd: handle delegated timestamps in SETATTR")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
When ATTR_ATIME_SET and ATTR_MTIME_SET are set in the ia_valid mask, the
notify_change() logic takes that to mean that the request should set
those values explicitly, and not override them with "now".
With the advent of delegated timestamps, similar functionality is needed
for the ctime. Add a ATTR_CTIME_SET flag, and use that to indicate that
the ctime should be accepted as-is. Also, clean up the if statements to
eliminate the extra negatives.
In setattr_copy() and setattr_copy_mgtime() use inode_set_ctime_deleg()
when ATTR_CTIME_SET is set, instead of basing the decision on ATTR_DELEG.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If the only flag left is ATTR_DELEG, then there are no changes to be
made.
Fixes: 7e13f4f8d2 ("nfsd: handle delegated timestamps in SETATTR")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The ia_ctime.tv_nsec field should be set to modify.nseconds.
Fixes: 7e13f4f8d2 ("nfsd: handle delegated timestamps in SETATTR")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The data type of loca_last_write_offset is newoffset4 and is switched
on a boolean value, no_newoffset, that indicates if a previous write
occurred or not. If no_newoffset is FALSE, an offset is not given.
This means that client does not try to update the file size. Thus,
server should not try to calculate new file size and check if it fits
into the segment range. See RFC 8881, section 12.5.4.2.
Sometimes the current incorrect logic may cause clients to hang when
trying to sync an inode. If layoutcommit fails, the client marks the
inode as dirty again.
Fixes: 9cf514ccfa ("nfsd: implement pNFS operations")
Cc: stable@vger.kernel.org
Co-developed-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
When pNFS client in the block or scsi layout mode sends layoutcommit
to MDS, a variable length array of modified extents is supplied within
the request. This patch allows the server to accept such extent arrays
if they do not fit within single memory page.
The issue can be reproduced when writing to a 1GB file using FIO with
O_DIRECT, 4K block and large I/O depth without preallocation of the
file. In this case, the server returns NFSERR_BADXDR to the client.
Co-developed-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Use the appropriate xdr function to decode the lc_newoffset field,
which is a boolean value. See RFC 8881, section 18.42.1.
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Remove dprintk in nfsd4_layoutcommit. These are not needed
in day to day usage, and the information is also available
in Wireshark when capturing NFS traffic.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Compilers may optimize the layout of C structures, so we should not rely
on sizeof struct and memcpy to encode and decode XDR structures. The byte
order of the fields should also be taken into account.
This patch adds the correct functions to handle the deviceid4 structure
and removes the pad field, which is currently not used by NFSD, from the
runtime state. The server's byte order is preserved because the deviceid4
blob on the wire is only used as a cookie by the client.
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Since the opaque is fixed in size, the caller already knows how many
bytes were decoded, on success. Thus, xdr_stream_decode_opaque_fixed()
doesn't need to return that value. And, xdr_stream_decode_u32 and _u64
both return zero on success.
This patch simplifies the caller's error checking to avoid potential
integer promotion issues.
Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This interface was deprecated by commit e6f7e1487a ("nfs_localio:
simplify interface to nfsd for getting nfsd_file") and is now
unused. So let's remove it.
Signed-off-by: NeilBrown <neil@brown.name>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The server-side sunrpc code currently calls pc_release before sending
the reply. Change svc_process and svc_process_bc to call pc_release
after sending the reply instead.
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: The fh_getattr() function is part of NFSD's file handle
API, so relocate it.
I've made it an un-inlined function so that trace points and new
functionality can easily be introduced. That increases the size of
nfsd.ko by about a page on my x86_64 system (out of 26MB; compiled
with -O2).
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: these helpers are part of the NFSD file handle API.
Relocate them to fs/nfsd/nfsfh.h.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
In xdr_stream_decode_opaque_auth(), zero-length checksum.len causes
checksum.data to be set to NULL. This triggers a NPD when accessing
checksum.data in gss_krb5_verify_mic_v2(). This patch ensures that
the value of checksum.len is not less than XDR_UNIT.
Fixes: 0653028e8f ("SUNRPC: Convert gss_verify_header() to use xdr_stream")
Cc: stable@kernel.org
Signed-off-by: Lei Lu <llfamsec@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Pull Rockchip clk driver updates from Heiko Stuebner:
Export the dsi-24MHz clock on the RK3368, which seems to get some
attention to enable DSI support there.
* tag 'v6.18-rockchip-clk1' of git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip:
clk: rockchip: rk3368: use clock ids for SCLK_MIPIDSI_24M
dt-bindings: clock: rk3368: Add SCLK_MIPIDSI_24M
UAPI Changes:
- Drop L3 bank mask reporting from the media GT on Xe3 and later. Only
do that for the primary GT. No userspace needs or uses it for media
and some platforms may report bogus values.
- Add SLPC power_profile sysfs interface with support for base and
power_saving modes (Vinay Belgaumkar, Rodrigo Vivi)
- Add configfs attributes to add post/mid context-switch commands
(Lucas De Marchi)
Cross-subsystem Changes:
- Fix hmm_pfn_to_map_order() usage in gpusvm and refactor APIs to
align with pieces previous handled by xe_hmm (Matthew Auld)
Core Changes:
- Add MEI driver for Late Binding Firmware Update/Upload
(Alexander Usyskin)
Driver Changes:
- Fix GuC CT teardown wrt TLB invalidation (Satyanarayana)
- Fix CCS save/restore on VF (Satyanarayana)
- Increase default GuC crash buffer size (Zhanjun)
- Allow to clear GT stats in debugfs to aid debugging (Matthew Brost)
- Add more SVM GT stats to debugfs (Matthew Brost)
- Fix error handling in VMA attr query (Himal)
- Move sa_info in debugfs to be per tile (Michal Wajdeczko)
- Limit number of retries upon receiving NO_RESPONSE_RETRY from GuC to
avoid endless loop (Michal Wajdeczko)
- Fix configfs handling for survivability_mode undoing user choice when
unbinding the module (Michal Wajdeczko)
- Refactor configfs attribute visibility to future-proof it and stop
exposing survivability_mode if not applicable (Michal Wajdeczko)
- Constify some functions (Harish Chegondi, Michal Wajdeczko)
- Add/extend more HW workarounds for Xe2 and Xe3
(Harish Chegondi, Tangudu Tilak Tirumalesh)
- Replace xe_hmm with gpusvm (Matthew Auld)
- Improve fake pci and WA kunit handling for testing new platforms
(Michal Wajdeczko)
- Reduce unnecessary PTE writes when migrating (Sanjay Yadav)
- Cleanup GuC interface definitions and log message (John Harrison)
- Small improvements around VF CCS (Michal Wajdeczko)
- Enable bus mastering for the I2C controller (Raag Jadav)
- Prefer devm_mutex of hand rolling it (Christophe JAILLET)
- Drop sysfs and debugfs attributes not available for VF (Michal Wajdeczko)
- GuC CT devm actions improvements (Michal Wajdeczko)
- Recommend new GuC versions for PTL and BMG (Julia Filipchuk)
- Improveme driver handling for exhaustive eviction using new
xe_validation wrapper around drm_exec (Thomas Hellström)
- Add and use printk wrappers for tile and device (Michal Wajdeczko)
- Better document workaround handling in Xe (Lucas De Marchi)
- Improvements on ARRAY_SIZE and ERR_CAST usage (Lucas De Marchi,
Fushuai Wang)
- Align CSS firmware headers with the GuC APIs (John Harrison)
- Test GuC to GuC (G2G) communication to aid debug in pre-production
firmware (John Harrison)
- Bail out driver probing if GuC fails to load (John Harrison)
- Allow error injection in xe_pxp_exec_queue_add()
(Daniele Ceraolo Spurio)
- Minor refactors in xe_svm (Shuicheng Lin)
- Fix madvise ioctl error handling (Shuicheng Lin)
- Use attribute groups to simplify sysfs registration
(Michal Wajdeczko)
- Add Late Binding Firmware implementation in Xe to work together with
the MEI component (Badal Nilawar, Daniele Ceraolo Spurio, Rodrigo
Vivi)
- Fix build with CONFIG_MODULES=n (Lucas De Marchi)
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/c2et6dnkst2apsgt46dklej4nprqdukjosb55grpaknf3pvcxy@t7gtn3hqtp6n
vhost_task_create() creates a task and keeps a reference to its
task_struct. That task may exit early via a signal and its task_struct
will be released.
A pending vhost_task_wake() will then attempt to wake the task and
access a task_struct which is no longer there.
Acquire a reference on the task_struct while creating the thread and
release the reference while the struct vhost_task itself is removed.
If the task exits early due to a signal, then the vhost_task_wake() will
still access a valid task_struct. The wake is safe and will be skipped
in this case.
Fixes: f9010dbdce ("fork, vhost: Use CLONE_THREAD to fix freezer/ps regression")
Reported-by: Sean Christopherson <seanjc@google.com>
Closes: https://lore.kernel.org/all/aKkLEtoDXKxAAWju@google.com/
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Message-Id: <20250918181144.Ygo8BZ-R@linutronix.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Sean Christopherson <seanjc@google.com>
Patch series "Expand scope of khugepaged anonymous collapse", v2.
Currently khugepaged does not collapse an anonymous region which does not
have a single writable pte. This is wasteful since a region mapped with
non-writable ptes, for example, non-writable VMAs mapped by the
application, won't benefit from THP collapse.
An additional consequence of this constraint is that MADV_COLLAPSE does
not perform a collapse on a non-writable VMA, and this restriction is
nowhere to be found on the manpage - the restriction itself sounds wrong
to me since the user knows the protection of the memory it has mapped, so
collapsing read-only memory via madvise() should be a choice of the user
which shouldn't be overridden by the kernel.
Therefore, remove this constraint.
On an arm64 bare metal machine, comparing with vanilla 6.17-rc2, an
average of 5% improvement is seen on some mmtests benchmarks, particularly
hackbench, with a maximum improvement of 12%. In the following table, (I)
denotes statistically significant improvement, (R) denotes statistically
significant regression.
+-------------------------+--------------------------------+---------------+
| mmtests/hackbench | process-pipes-1 (seconds) | -0.06% |
| | process-pipes-4 (seconds) | -0.27% |
| | process-pipes-7 (seconds) | (I) -12.13% |
| | process-pipes-12 (seconds) | (I) -5.32% |
| | process-pipes-21 (seconds) | (I) -2.87% |
| | process-pipes-30 (seconds) | (I) -3.39% |
| | process-pipes-48 (seconds) | (I) -5.65% |
| | process-pipes-79 (seconds) | (I) -6.74% |
| | process-pipes-110 (seconds) | (I) -6.26% |
| | process-pipes-141 (seconds) | (I) -4.99% |
| | process-pipes-172 (seconds) | (I) -4.45% |
| | process-pipes-203 (seconds) | (I) -3.65% |
| | process-pipes-234 (seconds) | (I) -3.45% |
| | process-pipes-256 (seconds) | (I) -3.47% |
| | process-sockets-1 (seconds) | 2.13% |
| | process-sockets-4 (seconds) | 1.02% |
| | process-sockets-7 (seconds) | -0.26% |
| | process-sockets-12 (seconds) | -1.24% |
| | process-sockets-21 (seconds) | 0.01% |
| | process-sockets-30 (seconds) | -0.15% |
| | process-sockets-48 (seconds) | 0.15% |
| | process-sockets-79 (seconds) | 1.45% |
| | process-sockets-110 (seconds) | -1.64% |
| | process-sockets-141 (seconds) | (I) -4.27% |
| | process-sockets-172 (seconds) | 0.30% |
| | process-sockets-203 (seconds) | -1.71% |
| | process-sockets-234 (seconds) | -1.94% |
| | process-sockets-256 (seconds) | -0.71% |
| | thread-pipes-1 (seconds) | 0.66% |
| | thread-pipes-4 (seconds) | 1.66% |
| | thread-pipes-7 (seconds) | -0.17% |
| | thread-pipes-12 (seconds) | (I) -4.12% |
| | thread-pipes-21 (seconds) | (I) -2.13% |
| | thread-pipes-30 (seconds) | (I) -3.78% |
| | thread-pipes-48 (seconds) | (I) -5.77% |
| | thread-pipes-79 (seconds) | (I) -5.31% |
| | thread-pipes-110 (seconds) | (I) -6.12% |
| | thread-pipes-141 (seconds) | (I) -4.00% |
| | thread-pipes-172 (seconds) | (I) -3.01% |
| | thread-pipes-203 (seconds) | (I) -2.62% |
| | thread-pipes-234 (seconds) | (I) -2.00% |
| | thread-pipes-256 (seconds) | (I) -2.30% |
| | thread-sockets-1 (seconds) | (R) 2.39% |
+-------------------------+--------------------------------+---------------+
+-------------------------+------------------------------------------------+
| mmtests/sysbench-mutex | sysbenchmutex-1 (usec) | -0.02% |
| | sysbenchmutex-4 (usec) | -0.02% |
| | sysbenchmutex-7 (usec) | 0.00% |
| | sysbenchmutex-12 (usec) | 0.12% |
| | sysbenchmutex-21 (usec) | -0.40% |
| | sysbenchmutex-30 (usec) | 0.08% |
| | sysbenchmutex-48 (usec) | 2.59% |
| | sysbenchmutex-79 (usec) | -0.80% |
| | sysbenchmutex-110 (usec) | -3.87% |
| | sysbenchmutex-128 (usec) | (I) -4.46% |
+-------------------------+--------------------------------+---------------+
This patch (of 2):
Currently khugepaged does not collapse an anonymous region which does not
have a single writable pte. This is wasteful since a region mapped with
non-writable ptes, for example, non-writable VMAs mapped by the
application, won't benefit from THP collapse.
An additional consequence of this constraint is that MADV_COLLAPSE does
not perform a collapse on a non-writable VMA, and this restriction is
nowhere to be found on the manpage - the restriction itself sounds wrong
to me since the user knows the protection of the memory it has mapped, so
collapsing read-only memory via madvise() should be a choice of the user
which shouldn't be overridden by the kernel.
Therefore, remove this restriction by not honouring SCAN_PAGE_RO.
Link: https://lkml.kernel.org/r/20250908075028.38431-1-dev.jain@arm.com
Link: https://lkml.kernel.org/r/20250908075028.38431-2-dev.jain@arm.com
Signed-off-by: Dev Jain <dev.jain@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Kiryl Shutsemau <kas@kernel.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Zach O'Keefe <zokeefe@google.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON_STAT calculates the idle time of a region using the region's age if
the region's nr_accesses is zero. If the nr_accesses value is non-zero
(positive), the idle time of the region becomes zero.
This means the users cannot know how warm and hot data is distributed,
using DAMON_STAT's memory_idle_ms_percentiles output. The other stat,
namely estimated_memory_bandwidth, can help understanding how the overall
access temperature of the system is, but it is still very rough
information. On production systems, actually, a significant portion of
the system memory is observed with zero idle time, and we cannot break it
down based on its internal hotness distribution.
Define the idle time of the region using its age, similar to those having
zero nr_accesses, but multiples '-1' to distinguish it. And expose that
using the same parameter interface, memory_idle_ms_percentiles.
Link: https://lkml.kernel.org/r/20250916183127.65708-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/damon/stat: expose auto-tuned intervals and non-idle
ages".
DAMON_STAT is intentionally providing limited information for easy
consumption of the information. From production fleet level usages, below
limitations are found, though.
The aggregation interval of DAMON_STAT represents the granularity of the
memory_idle_ms_percentiles. But the interval is auto-tuned and not
exposed to users, so users cannot know the granularity.
All memory regions of non-zero (positive) nr_accesses are treated as
having zero idle time. A significant portion of production systems have
such zero idle time. Hence breakdown of warm and hot data is nearly
impossible.
Make following changes to overcome the limitations. Expose the auto-tuned
aggregation interval with a new parameter named aggr_interval_us. Expose
the age of non-zero nr_accesses (how long >0 access frequency the region
retained) regions as a negative idle time.
This patch (of 2):
DAMON_STAT calculates the idle time for a region as the region's age
multiplied by the aggregation interval. That is, the aggregation interval
is the granularity of the idle time. Since the aggregation interval is
auto-tuned and not exposed to users, however, users cannot easily know in
what granularity the stat is made. Expose the tuned aggregation interval
in microseconds via a new parameter, aggr_interval_us.
Link: https://lkml.kernel.org/r/20250916183127.65708-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250916183127.65708-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damon_sample_mtier is assuming DAMON is ready to use in module_init time,
and uses its own hack to see if it is the time. Use damon_initialized(),
which is a way for seeing if DAMON is ready to be used that is more
reliable and better to maintain instead of the hack.
Link: https://lkml.kernel.org/r/20250916033511.116366-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damon_sample_prcl is assuming DAMON is ready to use in module_init time,
and uses its own hack to see if it is the time. Use damon_initialized(),
which is a way for seeing if DAMON is ready to be used that is more
reliable and better to maintain instead of the hack.
Link: https://lkml.kernel.org/r/20250916033511.116366-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damon_sample_wsse is assuming DAMON is ready to use in module_init time,
and uses its own hack to see if it is the time. Use damon_initialized(),
which is a way for seeing if DAMON is ready to be used that is more
reliable and better to maintain instead of the hack.
Link: https://lkml.kernel.org/r/20250916033511.116366-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON_LRU_SORT is assuming DAMON is ready to use in module_init time, and
uses its own hack to see if it is the time. Use damon_initialized(),
which is a way for seeing if DAMON is ready to be used that is more
reliable and better to maintain instead of the hack.
Link: https://lkml.kernel.org/r/20250916033511.116366-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON_RECLAIM is assuming DAMON is ready to use in module_init time, and
uses its own hack to see if it is the time. Use damon_initialized(),
which is a way for seeing if DAMON is ready to be used that is more
reliable and better to maintain instead of the hack.
Link: https://lkml.kernel.org/r/20250916033511.116366-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON_STAT is assuming DAMON is ready to use in module_init time, and uses
its own hack to see if it is the time. Use damon_initialized(), which is
a way for seeing if DAMON is ready to be used that is more reliable and
better to maintain instead of the hack.
Link: https://lkml.kernel.org/r/20250916033511.116366-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/damon: define and use DAMON initialization check
function".
DAMON is initialized in subsystem initialization time, by damon_init().
If DAMON API functions are called before the initialization, the
system could crash. Actually such issues happened and were fixed [1]
in the past. For the fix, DAMON API callers have updated to check if
DAMON is initialized or not, using their own hacks. The hacks are
unnecessarily duplicated on every DAMON API callers and therefore it
would be difficult to reliably maintain in the long term.
Make it reliable and easy to maintain. For this, implement a new DAMON
core layer API function that returns if DAMON is successfully
initialized. If it returns true, it means DAMON API functions are safe
to be used. After the introduction of the new API, update DAMON API
callers to use the new function instead of their own hacks.
This patch (of 7):
If DAMON is tried to be used when it is not yet successfully initialized,
the caller could be crashed. DAMON core layer is not providing a reliable
way to see if it is successfully initialized and therefore ready to be
used, though. As a result, DAMON API callers are implementing their own
hacks to see it. The hacks simply assume DAMON should be ready on module
init time. It is not reliable as DAMON initialization can indeed fail if
KMEM_CACHE() fails, and difficult to maintain as those are duplicates.
Implement a core layer API function for better reliability and
maintainability to replace the hacks with followup commits.
Link: https://lkml.kernel.org/r/20250916033511.116366-2-sj@kernel.org
Link: https://lkml.kernel.org/r/20250916033511.116366-2-sj@kernel.org
Link: https://lore.kernel.org/20250909022238.2989-1-sj@kernel.org [1]
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The effective quota of a scheme is initialized zero, which means there is
no quota. It is set based on user-specified time/quota/quota goals. But
the later value set is done only from the second charge window. As a
result, a scheme having a user-specified quota can work as not having the
quota (unexpectedly fast) for the first charge window. In practical and
common use cases the quota interval is not too long, and the scheme's
target access pattern is restrictive. Hence the issue should be modest.
That said, it is apparently an unintended misbehavior. Fix the problem by
setting esz on the first charge window.
Link: https://lkml.kernel.org/r/20250916032339.115817-3-sj@kernel.org
Fixes: 1cd2430300 ("mm/damon/schemes: implement time quota") # 5.16.x
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/damon: misc fixups and improvements for 6.18", v2.
Misc fixes and improvements for DAMON that are not critical and therefore
aims to be merged into Linux 6.18-rc1.
The first patch improves DAMON's age counting for nr_accesses zero to/from
non-zero changes.
The second patch fixes an initial DAMOS apply interval delay issue that is
not realistic but still could happen on an odd setup.
The third and the fourth patches update DAMON community meetup description
and DAMON user-space tool example command for DAMOS usage, respectively.
Finally, the fifth patch updates MAINTAINERS section name for DAMON to
just DAMON.
This patch (of 5):
DAMON resets the age of a region if its nr_accesses value has
significantly changed. Specifically, the threshold is calculated as 20%
of largest nr_accesses of the current snapshot. This means that regions
changing the nr_accesses from zero to small non-zero value or from a small
non-zero value to zero will keep the age. Since many users treat zero
nr_accesses regions special, this can be confusing. Kernel code including
DAMOS' regions priority calculation and DAMON_STAT's idle time calculation
also treat zero nr_accesses regions special. Make it unconfusing by
resetting the age when the nr_accesses changes between zero and a non-zero
value.
Link: https://lkml.kernel.org/r/20250916032339.115817-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250916032339.115817-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
While rare, memory allocation profiling can contain inaccurate counters if
slab object extension vector allocation fails. That allocation might
succeed later but prior to that, slab allocations that would have used
that object extension vector will not be accounted for. To indicate
incorrect counters, "accurate:no" marker is appended to the call site line
in the /proc/allocinfo output. Bump up /proc/allocinfo version to reflect
the change in the file format and update documentation.
Example output with invalid counters:
allocinfo - version: 2.0
0 0 arch/x86/kernel/kdebugfs.c:105 func:create_setup_data_nodes
0 0 arch/x86/kernel/alternative.c:2090 func:alternatives_smp_module_add
0 0 arch/x86/kernel/alternative.c:127 func:__its_alloc accurate:no
0 0 arch/x86/kernel/fpu/regset.c:160 func:xstateregs_set
0 0 arch/x86/kernel/fpu/xstate.c:1590 func:fpstate_realloc
0 0 arch/x86/kernel/cpu/aperfmperf.c:379 func:arch_enable_hybrid_capacity_scale
0 0 arch/x86/kernel/cpu/amd_cache_disable.c:258 func:init_amd_l3_attrs
49152 48 arch/x86/kernel/cpu/mce/core.c:2709 func:mce_device_create accurate:no
32768 1 arch/x86/kernel/cpu/mce/genpool.c:132 func:mce_gen_pool_create
0 0 arch/x86/kernel/cpu/mce/amd.c:1341 func:mce_threshold_create_device
[surenb@google.com: document new "accurate:no" marker]
Fixes: 39d117e04d15 ("alloc_tag: mark inaccurate allocation counters in /proc/allocinfo output")
[akpm@linux-foundation.org: simplification per Usama, reflow text]
[akpm@linux-foundation.org: add newline to prevent docs warning, per Randy]
Link: https://lkml.kernel.org/r/20250915230224.4115531-1-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Usama Arif <usamaarif642@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Cc: David Wang <00107082@163.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Although the oom_reaper is delayed and it gives the oom victim chance to
clean up its address space this might take a while especially for
processes with a large address space footprint. In those cases oom_reaper
might start racing with the dying task and compete for shared resources -
e.g. page table lock contention has been observed.
Reduce those races by reaping the oom victim from the other end of the
address space.
It is also a significant improvement for process_mrelease(). When a
process is killed, process_mrelease is used to reap the killed process and
often runs concurrently with the dying task. The test data shows that
after applying the patch, lock contention is greatly reduced during the
procedure of reaping the killed process.
The test is conducted on arm64. The following basic perf numbers show
that applying this patch significantly reduces pte spin lock contention.
Without the patch:
|--99.57%-- oom_reaper
| |--73.58%-- unmap_page_range
| | |--8.67%-- [hit in function]
| | |--41.59%-- __pte_offset_map_lock
| | |--29.47%-- folio_remove_rmap_ptes
| | |--16.11%-- tlb_flush_mmu
| |--19.94%-- tlb_finish_mmu
| |--3.21%-- folio_remove_rmap_ptes
With the patch:
|--99.53%-- oom_reaper
| |--55.77%-- unmap_page_range
| | |--20.49%-- [hit in function]
| | |--58.30%-- folio_remove_rmap_ptes
| | |--11.48%-- tlb_flush_mmu
| | |--3.33%-- folio_mark_accessed
| |--32.21%-- tlb_finish_mmu
| |--6.93%-- folio_remove_rmap_ptes
| |--0.69%-- __pte_offset_map_lock
Detailed breakdowns for both scenarios are provided below. The cumulative
time for oom_reaper plus exit_mmap(victim) in both cases is also
summarized, making the performance improvements clear.
+----------------------------------------------------------------+
| Category | Applying patch | Without patch |
+-------------------------------+----------------+---------------+
| Total running time | 132.6 | 167.1 |
| (exit_mmap + reaper work) | 72.4 + 60.2 | 90.7 + 76.4 |
+-------------------------------+----------------+---------------+
| Time waiting for pte spinlock | 1.0 | 33.1 |
| (exit_mmap + reaper work) | 0.4 + 0.6 | 10.0 + 23.1 |
+-------------------------------+----------------+---------------+
| folio_remove_rmap_ptes time | 42.0 | 41.3 |
| (exit_mmap + reaper work) | 18.4 + 23.6 | 22.4 + 18.9 |
+----------------------------------------------------------------+
From this report, we can see that:
1. The reduction in total time comes mainly from the decrease in time
spent on pte spinlock and other locks.
2. oom_reaper performs more work in some areas, but at the same time,
exit_mmap also handles certain tasks more efficiently, such as
folio_remove_rmap_ptes.
Here is a more detailed perf report. [1]
Link: https://lkml.kernel.org/r/20250915162946.5515-3-zhongjinji@honor.com
Link: https://lore.kernel.org/all/20250915162619.5133-1-zhongjinji@honor.com/ [1]
Signed-off-by: zhongjinji <zhongjinji@honor.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Improvements to Victim Process Thawing and OOM Reaper
Traversal Order", v10.
This patch series focuses on optimizing victim process thawing and
refining the traversal order of the OOM reaper. Since __thaw_task() is
used to thaw a single thread of the victim, thawing only one thread cannot
guarantee the exit of the OOM victim when it is frozen. Patch 1 thaw the
entire process of the OOM victim to ensure that OOM victims are able to
terminate themselves. Even if the oom_reaper is delayed, patch 2 is still
beneficial for reaping processes with a large address space footprint, and
it also greatly improves process_mrelease.
This patch (of 10):
OOM killer is a mechanism that selects and kills processes when the system
runs out of memory to reclaim resources and keep the system stable. But
the oom victim cannot terminate on its own when it is frozen, even if the
OOM victim task is thawed through __thaw_task(). This is because
__thaw_task() can only thaw a single OOM victim thread, and cannot thaw
the entire OOM victim process.
In addition, freezing_slow_path() determines whether a task is an OOM
victim by checking the task's TIF_MEMDIE flag. When a task is identified
as an OOM victim, the freezer bypasses both PM freezing and cgroup
freezing states to thaw it.
Historically, TIF_MEMDIE was a "this is the oom victim & it has access to
memory reserves" flag in the past. It has that thread vs. process
problems and tsk_is_oom_victim was introduced later to get rid of them and
other issues as well as the guarantee that we can identify the oom
victim's mm reliably for other oom_reaper.
Therefore, thaw_process() is introduced to unfreeze all threads within the
OOM victim process, ensuring that every thread is properly thawed. The
freezer now uses tsk_is_oom_victim() to determine OOM victim status,
allowing all victim threads to be unfrozen as necessary.
With this change, the entire OOM victim process will be thawed when an OOM
event occurs, ensuring that the victim can terminate on its own.
Link: https://lkml.kernel.org/r/20250915162946.5515-1-zhongjinji@honor.com
Link: https://lkml.kernel.org/r/20250915162946.5515-2-zhongjinji@honor.com
Signed-off-by: zhongjinji <zhongjinji@honor.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
For all the usual reasons, plus a new one. Calling
(void)arch_enter_lazy_mmu_mode();
deservedly blows up.
Cc: Balbir Singh <balbirs@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damon_lru_sort_apply_parameters() allocates a new DAMON context, stages
user-specified DAMON parameters on it, and commits to running DAMON
context at once, using damon_commit_ctx(). The code is, however, directly
updating the monitoring attributes of the running context. And the
attributes are over-written by later damon_commit_ctx() call. This means
that the monitoring attributes parameters are not really working. Fix the
wrong use of the parameter context.
Link: https://lkml.kernel.org/r/20250916031549.115326-1-sj@kernel.org
Fixes: a309694364 ("mm/damon/lru_sort: use damon_commit_ctx()")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: <stable@vger.kernel.org> [6.11+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jeff Layton
Sergey Bashirov
NeilBrown
Chuck Lever
Lei Lu
Dave Airlie
Mauro Carvalho Chehab
Yash Suthar
Stephen Boyd
Akira Yokosawa
Linus Torvalds
Peter Hilber
Alyssa Ross
Ashwini Sahu
Sebastian Andrzej Siewior
Dev Jain
SeongJae Park
Suren Baghdasaryan
zhongjinji
Andrew Morton
Muhammad Usama Anjum