On Thu, Jun 27, 2024 at 01:17:37PM -0700, Nhat Pham wrote: > syzbot detects that cachestat() is flushing stats, which can sleep, in > its RCU read section (see [1]). This is done in the > workingset_test_recent() step (which checks if the folio's eviction is > recent). > > Move the stat flushing step to before the RCU read section of cachestat, > and skip stat flushing during the recency check. > > [1]: https://lore.kernel.org/cgroups/000000000000f71227061bdf97e0@xxxxxxxxxx/ > > Reported-by: syzbot+b7f13b2d0cc156edf61a@xxxxxxxxxxxxxxxxxxxxxxxxx > Closes: https://lore.kernel.org/cgroups/000000000000f71227061bdf97e0@xxxxxxxxxx/ > Debugged-by: Johannes Weiner <hannes@xxxxxxxxxxx> > Suggested-by: Johannes Weiner <hannes@xxxxxxxxxxx> > Signed-off-by: Nhat Pham <nphamcs@xxxxxxxxx> > Fixes: b00684722262 ("mm: workingset: move the stats flush into workingset_test_recent()") > Cc: stable@xxxxxxxxxxxxxxx # v6.8+ Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
