On Wed, Nov 08, 2023 at 09:15:17AM -0800, Stefan Roesch wrote: > While qualifiying the 6.4 release, the following warning was detected in > messages: > > vmstat_refresh: nr_file_hugepages -15664 > > The warning is caused by the incorrect updating of the NR_FILE_THPS > counter in the function split_huge_page_to_list. The if case is checking > for folio_test_swapbacked, but the else case is missing the check for > folio_test_pmd_mappable. The other functions that manipulate the counter > like __filemap_add_folio and filemap_unaccount_folio have the > corresponding check. > > I have a test case, which reproduces the problem. It can be found here: > https://github.com/sroeschus/testcase/blob/main/vmstat_refresh/madv.c > > The test case reproduces on an XFS filesystem. Running the same test > case on a BTRFS filesystem does not reproduce the problem. > > AFAIK version 6.1 until 6.6 are affected by this problem. > > Signed-off-by: Stefan Roesch <shr@xxxxxxxxxxxx> > Co-debugged-by: Johannes Weiner <hannes@xxxxxxxxxxx> > Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
