Re: iomap_writepages WARN_ON_ONCE(PF_MEMALLOC)
Christoph Hellwig <[email protected]> Thu, 2 Jul 2026 03:59:24 -0700
| Newsgroups | dev.linux.lists.gfs2,org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-xfs |
|---|---|
| Message-ID | <[email protected]> |
On Wed, Jul 01, 2026 at 10:51:06PM +0200, Andreas Gruenbacher wrote: > Do you have any suggestions? > > The above is on RHEL-8, but a similar code path exists in cgroups v2, > triggered via: > > echo reclaim_amount > /sys/fs/cgroup/.../memory.reclaim > > That code path starts with: > > memory_reclaim -> user_proactive_reclaim -> try_to_free_mem_cgroup_pages -> PF_MEMALLOC is a sign of direct reclaim. cgroup code is doing really weird things when it is set and it is doing writeback.