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| author | SeongJae Park <sj@kernel.org> | 2025-09-08 13:15:12 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-09-13 13:05:36 -0700 |
| commit | e6a0deb6fa5b0fc134ee2aa127d1cfc9456d8445 (patch) | |
| tree | 2d1e364b64c829959753cc369370fdc00b924565 /mm/damon | |
| parent | 2da6de30e60dd9bb14600eff1cc99df2fa2ddae3 (diff) | |
| download | linux-e6a0deb6fa5b0fc134ee2aa127d1cfc9456d8445.tar.gz linux-e6a0deb6fa5b0fc134ee2aa127d1cfc9456d8445.tar.bz2 linux-e6a0deb6fa5b0fc134ee2aa127d1cfc9456d8445.zip | |
mm/damon/core: introduce damon_call_control->dealloc_on_cancel
Patch series "mm/damon/sysfs: fix refresh_ms control overwriting on
multi-kdamonds usages".
Automatic esssential DAMON/DAMOS status update feature of DAMON sysfs
interface (refresh_ms) is broken [1] for multiple DAMON contexts
(kdamonds) use case, since it uses a global single damon_call_control
object for all created DAMON contexts. The fields of the object,
particularly the list field is over-written for the contexts and it makes
unexpected results including user-space hangup and kernel crashes [2].
Fix it by extending damon_call_control for the use case and updating the
usage on DAMON sysfs interface to use per-context dynamically allocated
damon_call_control object.
This patch (of 2):
When damon_call_control->repeat is set, damon_call() is executed
asynchronously, and is eventually canceled when kdamond finishes. If the
damon_call_control object is dynamically allocated, finding the place to
deallocate the object is difficult. Introduce a new damon_call_control
field, namely dealloc_on_cancel, to ask the kdamond deallocates those
dynamically allocated objects when those are canceled.
Link: https://lkml.kernel.org/r/20250908201513.60802-3-sj@kernel.org
Link: https://lkml.kernel.org/r/20250908201513.60802-2-sj@kernel.org
Fixes: d809a7c64ba8 ("mm/damon/sysfs: implement refresh_ms file internal work")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Yunjeong Mun <yunjeong.mun@sk.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/damon')
| -rw-r--r-- | mm/damon/core.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/mm/damon/core.c b/mm/damon/core.c index c2e0b469fd43..08065b363972 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -2479,10 +2479,14 @@ static void kdamond_call(struct damon_ctx *ctx, bool cancel) mutex_lock(&ctx->call_controls_lock); list_del(&control->list); mutex_unlock(&ctx->call_controls_lock); - if (!control->repeat) + if (!control->repeat) { complete(&control->completion); - else + } else if (control->canceled && control->dealloc_on_cancel) { + kfree(control); + continue; + } else { list_add(&control->list, &repeat_controls); + } } control = list_first_entry_or_null(&repeat_controls, struct damon_call_control, list); |