github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-02 19:43:40 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

mm/shmem: add mTHP swpout fallback statistics in shmem_writeout()

Browse Source 
Currently, when shmem mTHPs are split and swapped out via
shmem_writeout(), there are no unified statistics to trace these mTHP
swpout fallback events.  This makes it difficult to analyze the prevalence
of mTHP splitting and fallback during swap operations, which is important
for memory diagnostics.

Here we add statistics counting for mTHP fallback to small pages when
splitting and swapping out in shmem_writeout().

Link: https://lkml.kernel.org/r/20251215024632.250149-1-tongweilin@linux.alibaba.com
Signed-off-by: Weilin Tong <tongweilin@linux.alibaba.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Weilin Tong 2025-12-15 10:46:32 +08:00 committed by Andrew Morton
parent ee628d9cc8
commit bf3480d7d0
1 changed files with 12 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
mm/shmem.c
View File

@ -1593,11 +1593,23 @@ int shmem_writeout(struct folio *folio, struct swap_iocb **plug,
}
if (split) {
int order;
try_split:
order = folio_order(folio);
/* Ensure the subpages are still dirty */
folio_test_set_dirty(folio);
if (split_folio_to_list(folio, folio_list))
goto redirty;
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
if (order >= HPAGE_PMD_ORDER) {
count_memcg_folio_events(folio, THP_SWPOUT_FALLBACK, 1);
count_vm_event(THP_SWPOUT_FALLBACK);
}
#endif
count_mthp_stat(order, MTHP_STAT_SWPOUT_FALLBACK);
folio_clear_dirty(folio);
}