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charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Rspamd-Queue-Id: 9D355160016 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: qkm6ribdwsgynnawc4zptkh5udxigr8u X-HE-Tag: 1701213312-894929 X-HE-Meta: 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 hveM+Yj4 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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 Tue, Nov 28, 2023 at 03:05:29PM -0800, Yosry Ahmed wrote: > On Tue, Nov 28, 2023 at 2:45 PM Minchan Kim wrote: > > > > On Tue, Nov 28, 2023 at 11:16:04AM +0100, Michal Hocko wrote: > > > On Tue 28-11-23 09:31:06, Huang, Ying wrote: > > > > Michal Hocko writes: > > > [...] > > > > > Right. On the other hand we could be more aggressive when dropping the > > > > > swapcache. Is there any actual reason why we cannot try to folio_free_swap > > > > > even when mem_cgroup_swap_full == F? > > > > > > > > If there are plenty free space in swap device, why not take advantage of > > > > it? > > > > > > Maybe a stupid question but what is the advantage of keeping around in > > > the swap cache? > > > > If the page is shared, we avoids addtional IO to bring them back so > > swap cache. > > I think this case is actually necessary for correctness, not just to > avoid additional IO. Otherwise subsequent swapins will create new > copies of the page, right? I think if the page was shared by MAP_SHARED, then, yes. I think if the page was shared by MAP_PRIVATE but CoW(e.g., fork), then, no.