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[109.81.86.48]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-482a5b816c0sm1827065f8f.33.2026.08.17.01.31.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Aug 2026 01:31:10 -0700 (PDT) Date: Mon, 17 Aug 2026 10:31:09 +0200 From: Michal Hocko To: Song Hu Cc: akpm@linux-foundation.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, hannes@cmpxchg.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, zhuhui@kylinos.cn, joshua.hahnjy@gmail.com, audra@redhat.com, bingfangguo@tencent.com Subject: Re: [PATCH] mm: memcg: flush empty per-cpu stock slots on memcg offlining Message-ID: References: <20260817025917.66233-1-husong@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260817025917.66233-1-husong@kylinos.cn> On Mon 17-08-26 10:59:17, Song Hu wrote: > refill_stock() takes a css reference for each cached memcg slot and > mem_cgroup_css_offline() relies on drain_all_stock() to release those > references before the cgroup can finish dying. > > consume_stock() can drive a slot's nr_pages to zero while its cached[] > pointer stays set. Is there any specific reason why the memcg stays in the cache slot without any pages? -- Michal Hocko SUSE Labs