cachestat: do not flush stats in recency check

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/[email protected]/

Link: https://lkml.kernel.org/r/[email protected]
Fixes: b00684722262 ("mm: workingset: move the stats flush into workingset_test_recent()")
Signed-off-by: Nhat Pham <[email protected]>
Reported-by: [email protected]
Closes: https://lore.kernel.org/cgroups/[email protected]/
Debugged-by: Johannes Weiner <[email protected]>
Suggested-by: Johannes Weiner <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Acked-by: Shakeel Butt <[email protected]>
Cc: Al Viro <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Kairui Song <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Yosry Ahmed <[email protected]>
Cc: <[email protected]>	[6.8+]
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions