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Wong" , gfs2 , linux-xfs@vger.kernel.org, linux-fsdevel , LKML , Tejun Heo , Johannes Weiner , Michal =?iso-8859-1?Q?Koutn=FD?= , cgroups@vger.kernel.org, Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , linux-mm@kvack.org Subject: Re: iomap_writepages WARN_ON_ONCE(PF_MEMALLOC) Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 595AB40007 X-Stat-Signature: bdwcsfja1hztcdkzeeywt1kuiuukokof X-HE-Tag: 1783126623-130817 X-HE-Meta: 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 OAj2eU39 HQwbht/2cogErJhJkr8s/OpF8hiBv3VGGsuhi175hlGZapa2jUJ1BvYj+7cmHsQngbI5+EcQ6AeZMaLN04j47wfl37+35f1siHHcQhwgDbV+oDGcoikFk7PXBvWxy6PO8YkdOL/KgqsfqksO8j+LKk/S+aaCemRPYOIrSzNENbOxc7e1ZLKtwiipMrBH86Wm0KOmnopqD1YDcZWZwh4FbWafUkfyy1yOQ6/TC+8xoiU+sA3DWG0AdVo/juLYDBM85B/EdD2jePHezAummE6/oOsvoCAB1Xu+hDh2YSQOsBEy6XEeU/PxadHwWhIyjc6oyV9ZnnjPrP1uqHCD/TaGEa+aE7Q== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Jul 02, 2026 at 03:59:24AM -0700, Christoph Hellwig wrote: > 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. If we're going to blame the cgroup people for doing weird things, let's cc them so they stand a chance of seeing this ... original at: https://lore.kernel.org/linux-fsdevel/CAHc6FU4tz8-HmEf2_XKT0NT8N=rv5OMcY79PxTACkXAVLOAUpg@mail.gmail.com/