Rename memcg_oom_recover() into memcg1_oom_recover() for consistency with
other memory cgroup v1-related functions.
Move the declaration in mm/memcontrol-v1.h to be nearby other memcg v1 oom
handling functions.
Link: https://lkml.kernel.org/r/20240625005906.106920-10-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cgroup v1 supports a complicated OOM handling in userspace mechanism,
which is not supported by cgroup v2. Let's move the corresponding code
into memcontrol-v1.c.
Aside from mechanical code movement this patch introduces two new
functions: memcg1_oom_prepare() and memcg1_oom_finish(). Those are
implementing cgroup v1-specific parts of the common memcg OOM handling
path.
Link: https://lkml.kernel.org/r/20240625005906.106920-9-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Rename memcg_check_events() into memcg1_check_events() for consistency
with other cgroup v1-specific functions.
Link: https://lkml.kernel.org/r/20240625005906.106920-8-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cgroup v1's memory controller contains a pretty complicated event
notifications mechanism which is not used on cgroup v2. Let's move the
corresponding code into memcontrol-v1.c.
Please, note, that mem_cgroup_event_ratelimit() remains in memcontrol.c,
otherwise it would require exporting too many details on memcg stats
outside of memcontrol.c.
Link: https://lkml.kernel.org/r/20240625005906.106920-7-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Rename exported function related to the charge move to have the memcg1_
prefix.
Link: https://lkml.kernel.org/r/20240625005906.106920-6-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Unlike the legacy cgroup v1 memory controller, cgroup v2 memory controller
doesn't support moving charged pages between cgroups.
It's a fairly large and complicated code which created a number of
problems in the past. Let's move this code into memcontrol-v1.c. It
shaves off 1k lines from memcontrol.c. It's also another step towards
making the legacy memory controller code optionally compiled.
Link: https://lkml.kernel.org/r/20240625005906.106920-5-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Rename exported function related to the softlimit reclaim to have memcg1_
prefix.
Link: https://lkml.kernel.org/r/20240625005906.106920-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Soft limits are cgroup v1-specific and are not supported by cgroup v2, so
let's move the corresponding code into memcontrol-v1.c.
Aside from simple moving the code, this commits introduces a trivial
memcg1_soft_limit_reset() function to reset soft limits and also moves the
global soft limit tree initialization code into a new memcg1_init()
function.
It also moves corresponding declarations shared between memcontrol.c and
memcontrol-v1.c into mm/memcontrol-v1.h.
Link: https://lkml.kernel.org/r/20240625005906.106920-3-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: memcg: separate legacy cgroup v1 code and put under
config option", v2.
Cgroups v2 have been around for a while and many users have fully adopted
them, so they never use cgroups v1 features and functionality. Yet they
have to "pay" for the cgroup v1 support anyway:
1) the kernel binary contains an unused cgroup v1 code,
2) some code paths have additional checks which are not needed,
3) some common structures like task_struct and mem_cgroup contain unused
cgroup v1-specific members.
Cgroup v1's memory controller has a number of features that are not
supported by cgroup v2 and their implementation is pretty much self
contained. Most notably, these features are: soft limit reclaim, oom
handling in userspace, complicated event notification system, charge
migration. Cgroup v1-specific code in memcontrol.c is close to 4k lines
in size and it's intervened with generic and cgroup v2-specific code.
It's a burden on developers and maintainers.
This patchset aims to solve these problems by:
1) moving cgroup v1-specific memcg code to the new mm/memcontrol-v1.c file,
2) putting definitions shared by memcontrol.c and memcontrol-v1.c into the
mm/memcontrol-v1.h header,
3) introducing the CONFIG_MEMCG_V1 config option, turned off by default,
4) making memcontrol-v1.c to compile only if CONFIG_MEMCG_V1 is set.
If CONFIG_MEMCG_V1 is not set, cgroup v1 memory controller is still available
for mounting, however no memory-specific control knobs are present.
This patch (of 14):
This patch introduces the mm/memcontrol-v1.c source file which will be
used for all legacy (cgroup v1) memory cgroup code. It also introduces
mm/memcontrol-v1.h to keep declarations shared between mm/memcontrol.c and
mm/memcontrol-v1.c.
As of now, let's compile it if CONFIG_MEMCG is set, similar to
mm/memcontrol.c. Later on it can be switched to use a separate config
option, so that the legacy code won't be compiled if not required.
Link: https://lkml.kernel.org/r/20240625005906.106920-1-roman.gushchin@linux.dev
Link: https://lkml.kernel.org/r/20240625005906.106920-2-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Now the implementation of stable_node_dup() causes chain()/chain_prune()
interfaces and usages are overcomplicated.
Why? stable_node_dup() only find and return a candidate stable_node for
sharing, so the users have to recheck using stable_node_dup_any() if any
non-candidate stable_node exist. And try to ksm_get_folio() from it
again.
Actually, stable_node_dup() can just return a best stable_node as it can,
then the users can check if it's a candidate for sharing or not.
The code is simplified too and fewer corner cases: such as stable_node and
stable_node_dup can't be NULL if returned tree_folio is not NULL.
Link: https://lkml.kernel.org/r/20240621-b4-ksm-scan-optimize-v2-3-1c328aa9e30b@linux.dev
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Stefan Roesch <shr@devkernel.io>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The code flow in cmp_and_merge_page() is suboptimal for handling the ksm
page and non-ksm page at the same time. For example:
- ksm page
1. Mostly just return if this ksm page is not migrated and this rmap_item
has been on the rmap hlist. Or we have to fix this rmap_item mapping.
2. But we absolutely don't need to checksum for this ksm page, since it
can't change.
- non-ksm page
1. First don't need to waste time searching stable tree if fast changing.
2. Should try to merge with zero page before search the stable tree.
3. Then search stable tree to find mergeable ksm page.
This patch optimizes the code flow so the handling differences between ksm
page and non-ksm page become clearer and more efficient too.
Link: https://lkml.kernel.org/r/20240621-b4-ksm-scan-optimize-v2-2-1c328aa9e30b@linux.dev
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Stefan Roesch <shr@devkernel.io>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/ksm: cmp_and_merge_page() optimizations and cleanup", v2.
This series mainly optimizes cmp_and_merge_page() to have more efficient
separate code flow for ksm page and non-ksm anon page.
- ksm page: don't need to calculate the checksum obviously.
- anon page: don't need to search stable tree if changing fast and try
to merge with zero page before searching ksm page on stable tree.
Please see the patch-2 for details.
Patch-3 is cleanup also a little optimization for the chain()/chain_prune
interfaces, which made the stable_tree_search()/stable_tree_insert() over
complex.
I have done simple testing using "hackbench -g 1 -l 300000" (maybe I need
to use a better workload) on my machine, have seen a little CPU usage
decrease of ksmd and some improvements of cmp_and_merge_page() latency:
We can see the latency of cmp_and_merge_page() when handling non-ksm anon
pages has been improved.
This patch (of 3):
In preparation for later changes, refactor out a new function called
try_to_merge_with_zero_page(), which tries to merge with zero page.
Link: https://lkml.kernel.org/r/20240621-b4-ksm-scan-optimize-v2-0-1c328aa9e30b@linux.dev
Link: https://lkml.kernel.org/r/20240621-b4-ksm-scan-optimize-v2-1-1c328aa9e30b@linux.dev
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Stefan Roesch <shr@devkernel.io>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When trying to allocate a hugepage with no reserved ones free, it may be
allowed in case a number of overcommit hugepages was configured (using
/proc/sys/vm/nr_overcommit_hugepages) and that number wasn't reached.
This allows for a behavior of having extra hugepages allocated
dynamically, if there're resources for it. Some sysadmins even prefer not
reserving any hugepages and setting a big number of overcommit hugepages.
But while attempting to allocate overcommit hugepages in a multi node
system (either NUMA or mempolicy/cpuset) said allocations might randomly
fail even when there're resources available for the allocation.
This happens due to allowed_mems_nr() only accounting for the number of
free hugepages in the nodes the current process belongs to and the surplus
hugepage allocation is done so it can be allocated in any node. In case
one or more of the requested surplus hugepages are allocated in a
different node, the whole allocation will fail due allowed_mems_nr()
returning a lower value.
So allocate surplus hugepages in one of the nodes the current process
belongs to.
Easy way to reproduce this issue is to use a 2+ NUMA nodes system:
# echo 0 >/proc/sys/vm/nr_hugepages
# echo 1 >/proc/sys/vm/nr_overcommit_hugepages
# numactl -m0 ./tools/testing/selftests/mm/map_hugetlb 2
Repeating the execution of map_hugetlb test application will eventually
fail when the hugepage ends up allocated in a different node.
[aris@ruivo.org: v2]
Link: https://lkml.kernel.org/r/20240701212343.GG844599@cathedrallabs.org
Link: https://lkml.kernel.org/r/20240621190050.mhxwb65zn37doegp@redhat.com
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Aristeu Rozanski <aris@ruivo.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Vishal Moola <vishal.moola@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The variable is supposed to be set via later migrate_pages() call.
However, the function does not do that when CONFIG_MIGRATION is unset.
Initialize the variable to zero.
Link: https://lkml.kernel.org/r/20240701165332.47495-1-sj@kernel.org
Fixes: 5311c0a2ee ("mm/damon/paddr: introduce DAMOS_MIGRATE_COLD action for demotion")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202406251102.GE07hqfQ-lkp@intel.com/
Cc: Honggyu Kim <honggyu.kim@sk.com>
Cc: Hyeongtak Ji <hyeongtak.ji@sk.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Folios of order <= 1 are not in deferred list, the check of order is added
into folio_undo_large_rmappable() from commit 8897277acf ("mm: support
order-1 folios in the page cache"), but there is a repeated check for
small folio (order 0) during each call of the
folio_undo_large_rmappable(), so only keep folio_order() check inside the
function.
In addition, move all the checks into header file to save a function call
for non-large-rmappable or empty deferred_list folio.
Link: https://lkml.kernel.org/r/20240521130315.46072-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
User could update max_nr_regions parameter while DAMON is running to a
value that smaller than the current number of regions that DAMON is
seeing. Such update could be done for reducing the monitoring overhead.
In the case, DAMON should merge regions aggressively more than normal
situation to ensure the new limit is successfully applied. Implement a
kselftest to ensure that.
Link: https://lkml.kernel.org/r/20240625180538.73134-9-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Users can update DAMON parameters while it is running, using 'commit'
DAMON sysfs interface command. For testing the feature in future tests,
implement a function for doing that on the test-purpose DAMON sysfs
interface wrapper Python module.
Link: https://lkml.kernel.org/r/20240625180538.73134-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Implement a kselftest for DAMON's {min,max}_nr_regions' parameters. The
test ensures both the minimum and the maximum number of regions limit is
respected even if the workload's real number of regions is less than the
minimum or larger than the maximum limits.
Link: https://lkml.kernel.org/r/20240625180538.73134-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Implement DAMON stop function on the test-purpose DAMON sysfs interface
wrapper Python module, _damon_sysfs.py. This feature will be used by
future DAMON tests that need to start/stop DAMON multiple times.
Link: https://lkml.kernel.org/r/20240625180538.73134-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Implement a test for DAMOS tried regions command of DAMON sysfs interface.
It ensures the expected number of monitoring regions are created using an
artificial memory access pattern generator program.
Link: https://lkml.kernel.org/r/20240625180538.73134-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
To test schemes_tried_regions feature, we need to have a program having
specific number of regions that having different access pattern. Existing
artificial access pattern generator, 'access_memory', cannot be used for
the purpose, since it accesses only one region at a given time. Extending
it could be an option, but since the purpose and the implementation are
pretty simple, implementing another one from the scratch is better.
Implement such another artificial memory access program that allocates
user-defined number/size regions and accesses even-numbered regions.
Link: https://lkml.kernel.org/r/20240625180538.73134-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Implement schemes_update_tried_regions DAMON sysfs command on
_damon_sysfs.py, to use on implementations of future tests for the
feature.
Link: https://lkml.kernel.org/r/20240625180538.73134-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "selftests/damon: test DAMOS tried regions and
{min,max}_nr_regions".
This patch series fix a minor issue in a program for DAMON selftest, and
implement new functionality selftests for DAMOS tried regions and
{min,max}_nr_regions. The test for max_nr_regions also test the recovery
from online tuning-caused limit violation, which was fixed by a previous
patch [1] titled "mm/damon/core: merge regions aggressively when
max_nr_regions is unmet".
The first patch fixes a minor problem in the articial memory access
pattern generator for tests. Following 3 patches (2-4) implement schemes
tried regions test. Then a couple of patches (5-6) implementing static
setup based {min,max}_nr_regions functionality test follows. Final two
patches (7-8) implement dynamic max_nr_regions update test.
[1] https://lore.kernel.org/20240624210650.53960C2BBFC@smtp.kernel.org
This patch (of 8):
'access_memory' is an artificial memory access pattern generator for DAMON
tests. It creates and accesses memory regions that the user specified the
number and size via the command line. However, real access part of the
program ignores the user-specified size of each region. Instead, it uses
a hard-coded value, 10 MiB. Fix it to use user-defined size.
Note that all existing 'access_memory' users are setting the region size
as 10 MiB. Hence no real problem has happened so far.
Link: https://lkml.kernel.org/r/20240625180538.73134-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20240625180538.73134-2-sj@kernel.org
Fixes: b5906f5f73 ("selftests/damon: add a test for update_schemes_tried_regions sysfs command")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Unify all conditions for initial readahead to simplify goto logic in
page_cache_sync_ra(). No functional changes.
Link: https://lkml.kernel.org/r/20240625101909.12234-10-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
try_context_readahead() has a single caller page_cache_sync_ra(). Fold
the function there to make ra state modifications more obvious. No
functional changes.
Link: https://lkml.kernel.org/r/20240625101909.12234-9-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Both async and sync readahead are handled by ondemand_readahead()
function. However there isn't actually much in common. Just move async
related parts into page_cache_ra_async() and sync related parts to
page_cache_ra_sync(). No functional changes.
Link: https://lkml.kernel.org/r/20240625101909.12234-8-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
ondemand_readahead() scales up the readahead window if the current read
would hit the readahead mark placed by itself. However the condition is
mostly dead code because:
a) In case of async readahead we always increase ra->start so ra->start
== index is never true.
b) In case of sync readahead we either go through
try_context_readahead() in which case ra->async_size == 1 < ra->size or
we go through initial_readahead where ra->async_size == ra->size iff
ra->size == max_pages.
So the only practical effect is reducing async_size for large initial
reads. Make the code more obvious.
Link: https://lkml.kernel.org/r/20240625101909.12234-7-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
page_cache_ra_order() scales folio order down so that is fully fits within
readahead window. Thus the code handling the case where we walked past
the readahead window is a dead code. Remove it.
Link: https://lkml.kernel.org/r/20240625101909.12234-6-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The index argument of page_cache_async_readahead() is just folio->index so
there's no point in passing is separately. Drop it.
Link: https://lkml.kernel.org/r/20240625101909.12234-5-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Current index to readahead is tracked in readahead_control and properly
updated by page_cache_ra_unbounded() (read_pages() in fact). So there's
no need to track the index separately in force_page_cache_ra().
Link: https://lkml.kernel.org/r/20240625101909.12234-4-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When we succeed in creating some folios in page_cache_ra_order() but then
need to fallback to single page folios, we don't shorten the amount to
read passed to do_page_cache_ra() by the amount we've already read. This
then results in reading more and also in placing another readahead mark in
the middle of the readahead window which confuses readahead code. Fix the
problem by properly reducing number of pages to read.
Link: https://lkml.kernel.org/r/20240625101909.12234-3-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
page_cache_next_miss() should return value outside of the specified range
when no hole is found. However currently it will return the last index
*in* the specified range confusing ondemand_readahead() to think there's a
hole in the searched range and upsetting readahead logic.
Link: https://lkml.kernel.org/r/20240625101909.12234-2-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: Fix various readahead quirks".
When we were internally testing performance of recent kernels, we have
noticed quite variable performance of readahead arising from various
quirks in readahead code. So I went on a cleaning spree there. This is a
batch of patches resulting out of that. A quick testing in my test VM
with the following fio job file:
[global]
direct=0
ioengine=sync
invalidate=1
blocksize=4k
size=10g
readwrite=read
[reader]
numjobs=1
shows that this patch series improves the throughput from variable one in
310-340 MB/s range to rather stable one at 350 MB/s. As a side effect
these cleanups also address the issue noticed by Bruz Zhang [1].
[1] https://lore.kernel.org/all/20240618114941.5935-1-zhangpengpeng0808@gmail.com/
Zhang Peng reported:
: I test this batch of patch with fio, it indeed has a huge sppedup
: in sequential read when block size is 4KiB. The result as follow,
: for async read, iodepth is set to 128, and other settings
: are self-evident.
:
: casename upstream withFix speedup
: ---------------- -------- -------- -------
: randread-4k-sync 48991 47
: seqread-4k-sync 1162758 14229
: seqread-1024k-sync 1460208 1452522
: randread-4k-libaio 47467 4730
: randread-4k-posixaio 49190 49512
: seqread-4k-libaio 1085932 1234635
: seqread-1024k-libaio 1423341 1402214 -1
: seqread-4k-posixaio 1165084 1369613 1
: seqread-1024k-posixaio 1435422 1408808 -1.8
This patch (of 10):
page_cache_sync_ra() is called when a folio we want to read is not in the
page cache. It is expected that it creates the folio (and perhaps the
following folios as well) and submits reads for them unless some error
happens. However if index == ra->start + ra->size, ondemand_readahead()
will treat the call as another async readahead hit. Thus ra->start will
be advanced and we create pages and queue reads from ra->start + ra->size
further. Consequentially the page at 'index' is not created and
filemap_get_pages() has to always go through filemap_create_folio() path.
This behavior has particularly unfortunate consequences when we have two
IO threads sequentially reading from a shared file (as is the case when
NFS serves sequential reads). In that case what can happen is:
suppose ra->size == ra->async_size == 128, ra->start = 512
T1 T2
reads 128 pages at index 512
- hits async readahead mark
filemap_readahead()
ondemand_readahead()
if (index == expected ...)
ra->start = 512 + 128 = 640
ra->size = 128
ra->async_size = 128
page_cache_ra_order()
blocks in ra_alloc_folio()
reads 128 pages at index 640
- no page found
page_cache_sync_readahead()
ondemand_readahead()
if (index == expected ...)
ra->start = 640 + 128 = 768
ra->size = 128
ra->async_size = 128
page_cache_ra_order()
submits reads from 768
- still no page found at index 640
filemap_create_folio()
- goes on to index 641
page_cache_sync_readahead()
ondemand_readahead()
- founds ra is confused,
trims is to small size
finds pages were already inserted
And as a result read performance suffers.
Fix the problem by triggering async readahead case in ondemand_readahead()
only if we are calling the function because we hit the readahead marker.
In any other case we need to read the folio at 'index' and thus we cannot
really use the current ra state.
Note that the above situation could be viewed as a special case of
file->f_ra state corruption. In fact two thread reading using the shared
file can also seemingly corrupt file->f_ra in interesting ways due to
concurrent access. I never saw that in practice and the fix is going to
be much more complex so for now at least fix this practical problem while
we ponder about the theoretically correct solution.
Link: https://lkml.kernel.org/r/20240625100859.15507-1-jack@suse.cz
Link: https://lkml.kernel.org/r/20240625101909.12234-1-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Zhang Peng <zhangpengpeng0808@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently we always take a folio reference even if migration will not even
be tried or isolation failed, requiring us to grab+drop an additional
reference.
Further, we end up calling folio_likely_mapped_shared() while the folio
might have already been unmapped, because after we dropped the PTL, that
can easily happen. We want to stop touching mapcounts and friends from
such context, and only call folio_likely_mapped_shared() while the folio
is still mapped: mapcount information is pretty much stale and unreliable
otherwise.
So let's move checks into numamigrate_isolate_folio(), rename that
function to migrate_misplaced_folio_prepare(), and call that function from
callsites where we call migrate_misplaced_folio(), but still with the PTL
held.
We can now stop taking temporary folio references, and really only take a
reference if folio isolation succeeded. Doing the
folio_likely_mapped_shared() + folio isolation under PT lock is now
similar to how we handle MADV_PAGEOUT.
While at it, combine the folio_is_file_lru() checks.
[david@redhat.com: fix list_del() corruption]
Link: https://lkml.kernel.org/r/8f85c31a-e603-4578-bf49-136dae0d4b69@redhat.com
Link: https://lkml.kernel.org/r/20240626191129.658CFC32782@smtp.kernel.org
Link: https://lkml.kernel.org/r/20240620212935.656243-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Tested-by: Donet Tom <donettom@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/migrate: move NUMA hinting fault folio isolation + checks
under PTL".
Let's just return 0 on success, which is less confusing.
... especially because we got it wrong in the migrate.h stub where we
have "return -EAGAIN; /* can't migrate now */" instead of "return 0;".
Likely this wrong return value doesn't currently matter, but it certainly
adds confusion.
We'll add migrate_misplaced_folio_prepare() next, where we want to use the
same "return 0 on success" approach, so let's just clean this up.
Link: https://lkml.kernel.org/r/20240620212935.656243-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240620212935.656243-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Donet Tom <donettom@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 2b5067a814 ("mm: mmap_lock: add tracepoints around lock
acquisition") introduced TRACE_MMAP_LOCK_EVENT() macro using
preempt_disable() in order to let get_mm_memcg_path() return a percpu
buffer exclusively used by normal, softirq, irq and NMI contexts
respectively.
Commit 832b507253 ("mm: mmap_lock: use local locks instead of disabling
preemption") replaced preempt_disable() with local_lock(&memcg_paths.lock)
based on an argument that preempt_disable() has to be avoided because
get_mm_memcg_path() might sleep if PREEMPT_RT=y.
But syzbot started reporting
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
and
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
messages, for local_lock() does not disable IRQ.
We could replace local_lock() with local_lock_irqsave() in order to
suppress these messages. But this patch instead replaces percpu buffers
with on-stack buffer, for the size of each buffer returned by
get_memcg_path_buf() is only 256 bytes which is tolerable for allocating
from current thread's kernel stack memory.
Link: https://lkml.kernel.org/r/ef22d289-eadb-4ed9-863b-fbc922b33d8d@I-love.SAKURA.ne.jp
Reported-by: syzbot <syzbot+40905bca570ae6784745@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=40905bca570ae6784745
Fixes: 832b507253 ("mm: mmap_lock: use local locks instead of disabling preemption")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
sparse complains that __user pointers are being passed to functions that
expect non-__user ones. In all cases, these functions are in fact working
with user pointers, only the tag is missing. Add it.
Link: https://lkml.kernel.org/r/20240627145754.27333-2-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406272033.KejtfLkw-lkp@intel.com/
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The unwind code can read uninitialized frames. Furthermore, even in the
good case, KMSAN does not emit shadow for backchains. Therefore disable
it for the unwinding functions.
Link: https://lkml.kernel.org/r/20240621113706.315500-37-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
uaccess.h uses instrument_get_user() and instrument_put_user(), which are
defined in linux/instrumented.h. Currently we get this header from
somewhere else by accident; prefer to be explicit about it and include it
directly.
Link: https://lkml.kernel.org/r/20240621113706.315500-36-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Suggested-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
put_user() uses inline assembly with precise constraints, so Clang is in
principle capable of instrumenting it automatically. Unfortunately, one
of the constraints contains a dereferenced user pointer, and Clang does
not currently distinguish user and kernel pointers. Therefore KMSAN
attempts to access shadow for user pointers, which is not a right thing to
do.
An obvious fix to add __no_sanitize_memory to __put_user_fn() does not
work, since it's __always_inline. And __always_inline cannot be removed
due to the __put_user_bad() trick.
A different obvious fix of using the "a" instead of the "+Q" constraint
degrades the code quality, which is very important here, since it's a hot
path.
Instead, repurpose the __put_user_asm() macro to define
__put_user_{char,short,int,long}_noinstr() functions and mark them with
__no_sanitize_memory. For the non-KMSAN builds make them __always_inline
in order to keep the generated code quality. Also define
__put_user_{char,short,int,long}() functions, which call the
aforementioned ones and which *are* instrumented, because they call KMSAN
hooks, which may be implemented as macros.
The same applies to get_user() as well.
Link: https://lkml.kernel.org/r/20240621113706.315500-35-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add KMSAN support for the s390 implementations of the string functions.
Do this similar to how it's already done for KASAN, except that the
optimized memset{16,32,64}() functions need to be disabled: it's important
for KMSAN to know that they initialized something.
The way boot code is built with regard to string functions is problematic,
since most files think it's configured with sanitizers, but boot/string.c
doesn't. This creates various problems with the memset64() definitions,
depending on whether the code is built with sanitizers or fortify. This
should probably be streamlined, but in the meantime resolve the issues by
introducing the IN_BOOT_STRING_C macro, similar to the existing
IN_ARCH_STRING_C macro.
Link: https://lkml.kernel.org/r/20240621113706.315500-33-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The pages for the KMSAN metadata associated with most kernel mappings are
taken from memblock by the common code. However, vmalloc and module
metadata needs to be defined by the architectures.
Be a little bit more careful than x86: allocate exactly MODULES_LEN for
the module shadow and origins, and then take 2/3 of vmalloc for the
vmalloc shadow and origins. This ensures that users passing small
vmalloc= values on the command line do not cause module metadata
collisions.
Link: https://lkml.kernel.org/r/20240621113706.315500-32-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lockdep generates the following false positives with KMSAN on s390x:
[ 6.063666] DEBUG_LOCKS_WARN_ON(lockdep_hardirqs_enabled())
[ ...]
[ 6.577050] Call Trace:
[ 6.619637] [<000000000690d2de>] check_flags+0x1fe/0x210
[ 6.665411] ([<000000000690d2da>] check_flags+0x1fa/0x210)
[ 6.707478] [<00000000006cec1a>] lock_acquire+0x2ca/0xce0
[ 6.749959] [<00000000069820ea>] _raw_spin_lock_irqsave+0xea/0x190
[ 6.794912] [<00000000041fc988>] __stack_depot_save+0x218/0x5b0
[ 6.838420] [<000000000197affe>] __msan_poison_alloca+0xfe/0x1a0
[ 6.882985] [<0000000007c5827c>] start_kernel+0x70c/0xd50
[ 6.927454] [<0000000000100036>] startup_continue+0x36/0x40
Between trace_hardirqs_on() and `stosm __mask, 3` lockdep thinks that
interrupts are on, but on the CPU they are still off. KMSAN
instrumentation takes spinlocks, giving lockdep a chance to see and
complain about this discrepancy.
KMSAN instrumentation is inserted in order to poison the __mask variable.
Disable instrumentation in the respective functions. They are very small
and it's easy to see that no important metadata updates are lost because
of this.
Link: https://lkml.kernel.org/r/20240621113706.315500-31-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
s390 uses assembly code to initialize ftrace_regs and call
kprobe_ftrace_handler(). Therefore, from the KMSAN's point of view,
ftrace_regs is poisoned on kprobe_ftrace_handler() entry. This causes
KMSAN warnings when running the ftrace testsuite.
Fix by trusting the assembly code and always unpoisoning ftrace_regs in
kprobe_ftrace_handler().
Link: https://lkml.kernel.org/r/20240621113706.315500-30-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diagnose 224 stores 4k bytes, which currently cannot be deduced from the
inline assembly constraints. This leads to KMSAN false positives.
Fix the constraints by using a 4k-sized struct instead of a raw pointer.
While at it, prettify them too.
Link: https://lkml.kernel.org/r/20240621113706.315500-29-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
