On Fri, 18 Oct 2024 10:51:30 +0200 Greg KH gregkh@linuxfoundation.org wrote:
On Wed, Oct 16, 2024 at 09:49:49AM -0700, Chris Li wrote:
[ Upstream commit 0885ef4705607936fc36a38fd74356e1c465b023 ]
I found a regression on mm-unstable during my swap stress test, using tmpfs to compile linux. The test OOM very soon after the make spawns many cc processes.
It bisects down to this change: 33dfe9204f29b415bbc0abb1a50642d1ba94f5e9 (mm/gup: clear the LRU flag of a page before adding to LRU batch)
Yu Zhao propose the fix: "I think this is one of the potential side effects -- Huge mentioned earlier about isolate_lru_folios():"
I test that with it the swap stress test no longer OOM.
Link: https://lore.kernel.org/r/CAOUHufYi9h0kz5uW3LHHS3ZrVwEq-kKp8S6N-MZUmErNAXoXm... Link: https://lkml.kernel.org/r/20240905-lru-flag-v2-1-8a2d9046c594@kernel.org Fixes: 33dfe9204f29 ("mm/gup: clear the LRU flag of a page before adding to LRU batch") Signed-off-by: Chris Li chrisl@kernel.org Suggested-by: Yu Zhao yuzhao@google.com Suggested-by: Hugh Dickins hughd@google.com Closes: https://lore.kernel.org/all/CAF8kJuNP5iTj2p07QgHSGOJsiUfYpJ2f4R1Q5-3BN9JiD9W... Signed-off-by: Andrew Morton akpm@linux-foundation.org
mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Again, for mm changes, we need an explicit ack from the mm maintainers before we can take them. I'll wait for that.
Yes, please proceed with the backport. It looks like the cc:stable got lost because it wasn't in the original commit.
btw Chris, that was a quite poor changelog. It didn't explain the code change at all!