On Fri, May 28, 2021 at 10:58:04AM +0800, Ming Lei wrote: > On Wed, May 26, 2021 at 03:25:57PM -0700, Roman Gushchin wrote: > > Asynchronously try to release dying cgwbs by switching clean attached > > inodes to the bdi's wb. It helps to get rid of per-cgroup writeback > > structures themselves and of pinned memory and block cgroups, which > > are way larger structures (mostly due to large per-cpu statistics > > data). It helps to prevent memory waste and different scalability > > problems caused by large piles of dying cgroups. > > > > A cgwb cleanup operation can fail due to different reasons (e.g. the > > cgwb has in-glight/pending io, an attached inode is locked or isn't > > clean, etc). In this case the next scheduled cleanup will make a new > > attempt. An attempt is made each time a new cgwb is offlined (in other > > words a memcg and/or a blkcg is deleted by a user). In the future an > > additional attempt scheduled by a timer can be implemented. > > > > Signed-off-by: Roman Gushchin <guro@xxxxxx> > > --- > > fs/fs-writeback.c | 35 ++++++++++++++++++ > > include/linux/backing-dev-defs.h | 1 + > > include/linux/writeback.h | 1 + > > mm/backing-dev.c | 61 ++++++++++++++++++++++++++++++-- > > 4 files changed, 96 insertions(+), 2 deletions(-) > > > > Hello Roman, > > The following kernel panic is triggered by this patch: Hello Ming! Thank you for the report and for trying my patches! I think I know what it is and will fix in the next version. Thanks!
