Am Montag, 18. Februar 2019, 14:34:52 schrieb Sasha Levin:
On Mon, Feb 18, 2019 at 10:30:44AM -0500, Rik van Riel wrote:
On Mon, 2019-02-18 at 14:43 +0100, Greg Kroah-Hartman wrote:
4.20-stable review patch. If anyone has any objections, please let me know.
From: Dave Chinner dchinner@redhat.com
commit a9a238e83fbb0df31c3b9b67003f8f9d1d1b6c96 upstream.
This reverts commit 172b06c32b9497 ("mm: slowly shrink slabs with a relatively small number of objects").
This revert will result in the slab caches of dead cgroups with a small number of remaining objects never getting reclaimed, which can be a memory leak in some configurations.
What's the "right" choice though? we get either leaky cgroups or hanging xfs.
This not only made xfs hang. (Since 4.19.3) on two of our servers ext4 got so sluggish that login with ssh needed a minute and more. bash tab completion was unusable. Sometimes systemd-journald was restarted with "Watchdog timeout (limit 3min)!", (journal also was on ext4).
But hey, that's your tradeoff to make.
I don't think that any decision was made here, the stable tree simply follows upstream with regards to fixes and bugs such as these: we remain "bug compatible" with upstream in these scenarios, there was no decision made to prefer either bug.
-- Thanks, Sasha
Regards