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charset="UTF-8" X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 47A8AA0015 X-Rspam-User: X-Stat-Signature: ce39t6zarhw86631itam7qtawugcgiqa X-HE-Tag: 1673459361-442166 X-HE-Meta: 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 nok7mThP wuCmxpxH9EpamW0dNsmdwfp4qre354T3mQ4mtFGT1W9T38HP08MvXNmHME6P7DB+LjKc4kSUeYdrKMyogg3vNc1wmYj6wfEzvLA1E 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: On Wed, Jan 11, 2023 at 9:37 AM Michal Hocko wrote: > > On Wed 11-01-23 09:04:41, Suren Baghdasaryan wrote: > > On Wed, Jan 11, 2023 at 8:44 AM Michal Hocko wrote: > > > > > > On Wed 11-01-23 08:28:49, Suren Baghdasaryan wrote: > > > [...] > > > > Anyhow. Sounds like the overhead of the current design is small enough > > > > to remove CONFIG_PER_VMA_LOCK and let it depend only on architecture > > > > support? > > > > > > Yes. Further optimizations can be done on top. Let's not over optimize > > > at this stage. > > > > Sure, I won't optimize any further. > > Just to expand on your question. Original design would be problematic > > for embedded systems like Android. It notoriously has a high number of > > VMAs due to anonymous VMAs being named, which prevents them from > > merging. > > What is the usual number of VMAs in that environment? I've seen some games which had over 4000 VMAs but that's on the upper side. In my calculations I used 40000 VMAs as a ballpark number and rough calculations before size optimization would increase memory consumption by ~2M (depending on the lock placement in vm_area_struct it would vary a bit). In Android, the performance team flags any change that exceeds 500KB, so it would raise questions. > > -- > Michal Hocko > SUSE Labs