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Thu, 17 Apr 2025 07:58:27 -0700 (PDT) Date: Thu, 17 Apr 2025 10:58:26 -0400 From: Johannes Weiner To: Muchun Song Cc: mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, akpm@linux-foundation.org, david@fromorbit.com, zhengqi.arch@bytedance.com, yosry.ahmed@linux.dev, nphamcs@gmail.com, chengming.zhou@linux.dev, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, hamzamahfooz@linux.microsoft.com, apais@linux.microsoft.com Subject: Re: [PATCH RFC 06/28] mm: thp: introduce folio_split_queue_lock and its variants Message-ID: <20250417145826.GI780688@cmpxchg.org> References: <20250415024532.26632-1-songmuchun@bytedance.com> <20250415024532.26632-7-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250415024532.26632-7-songmuchun@bytedance.com> X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: CA182C0003 X-Stat-Signature: dc6dj566xmtjc7zaf3x643jw9ozhrmuz X-Rspam-User: X-HE-Tag: 1744901908-984639 X-HE-Meta: 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 3fxOgRvf 0Ku+rLTjr1vBtkzKOD/Rq293veRlL6cP8iBytblQpJ9ZiJhFr9t34RDqibgOhOrN3exdax76QQcgtDcuUwcTsCN0VRLBzBceDEbdr+d2jHQ9eU2m0/g0Eya4ToU//dmqqp1BuQFBP1IpngExRP+6R9Q6oArlnv5iiOIW8xuJJyxJt4PTZ08KcuJoeIb+wj1B6xLh90taGAj0wRbC5EsCuYHac+3Rnvm/hJ4f+0G71+zdEx3/ASGjVukghrcxbuq2LvNdDF3U0S+3hLo7cbBhJh8GcV9UclGQZs1qvfD7yK3LN6OG68FNEvt+ngYKbZYG0dFEXCzNgYyjRH7Er7mqMmFlTkvfNSXqV9sUaD7TlhURqJBPzgv8Dn0rbUI1mW9tk3Uc1Hr3w8y/kIFADqtTu5NEp/UDRUa7q17p252Ij87jBeXqm3kBHJXkvco/17hApcup+6+nh6b7JAySnSztf1Y+cAVvVt+Xfiq9e805tmReBtj4jr+rGlS5lbVff4Taybc6gu++fs3IpzVjCqv5tM5h2KQ6oEPZZFTTPeljgO0nKzz+fEmRdY0HY9g== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Apr 15, 2025 at 10:45:10AM +0800, Muchun Song wrote: > In future memcg removal, the binding between a folio and a memcg may change, > making the split lock within the memcg unstable when held. > > A new approach is required to reparent the split queue to its parent. This > patch starts introducing a unified way to acquire the split lock for future > work. > > It's a code-only refactoring with no functional changes. > > Signed-off-by: Muchun Song Acked-by: Johannes Weiner