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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 1AAC740018 X-Stat-Signature: dbww99ng73bstbd5z1nf7dm4qmjfwtpt X-Rspam-User: X-HE-Tag: 1721007133-122319 X-HE-Meta: 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 71cGS/OU 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 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 7/12/24 3:27 PM, Vlastimil Babka wrote: >> I checked the history of slab for this part. It introduced >> from commit 10befea91b61c ("mm: memcg/slab: use a single set of kmem_caches for all allocations") >> But still don't know why !page_has_obj_cgroups followed by memcg_alloc_page_obj_cgroups. Anyone like >> to give a hints? >> >> page = virt_to_head_page(p[i]); >> + >> + if (!page_has_obj_cgroups(page) && >> + memcg_alloc_page_obj_cgroups(page, s, flags)) { >> + obj_cgroup_uncharge(objcg, obj_full_size(s)); >> + continue; >> + } > I'm not sure I understand your question. The code is trying to charge the > allocation to a memcg and use the objext.memcg to associate that memcg to > the object so it can be properly uncharged when freeing. > When it's the first object in the particular slab page to be charged, the > objext may not be yet allocated, so it has has to be allocated at that point. I see. Thanks for explanation!