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charset="us-ascii" X-Rspamd-Queue-Id: ABA0A160017 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: 41hf81i8ou1teep45z3s8cn3153rioho X-HE-Tag: 1708629364-532167 X-HE-Meta: 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 pQQi0kjb 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000010, 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 Thu, Feb 22, 2024 at 11:02:24AM -0800, Luis Chamberlain wrote: > On Fri, Feb 02, 2024 at 02:29:40PM +0000, Matthew Wilcox wrote: > > So my modest proposal is that we completely rearchitect how we handle > > swap. Instead of putting swp entries in the page tables (and in shmem's > > case in the page cache), we turn swap into an (object, offset) lookup > > (just like a filesystem). That means that each anon_vma becomes its > > own swap object and each shmem inode becomes its own swap object. > > The swap system can then borrow techniques from whichever filesystem > > it likes to do (object, offset, length) -> n x (device, block) mappings. > > What happened to Yosry or Chris's last year's pony [0]? In order to try For me, I unfortunately got occuppied with other projects and don't have the bandwidth to work on it for now :/ I don't want to put anyone on the spot, but I think Nhat may have been thinking about pursuing a version of this at some point. > to take a stab at this we started with adding large folios to tmpfs, > which Daniel Gomez has taken on, as its a simple filesystem and with > large folios can enable us to easily test large folio swap support too. > Daniel first tried fixing lseek issue with huge pages [1] and on top of > that he has patches (a new RFC not posted yet) which do add large folios > support to tmpfs. Hugh has noted the lskeek changes are incorrect and > suggested instead a fix for the failed tests in fstests. If we get > agreement on Hugh's approach then we have a step forward with tmpfs and > later we hope this will make it easier to test swap changes. > > Its probably then a good time to ask, do we have a list of tests for > swap to ensure we don't break things if we add large folio support? > We can at least start with a good baseline of tests for that. > > [0] https://lwn.net/Articles/932077/ > [1] https://lkml.kernel.org/r/20240209142901.126894-1-da.gomez@samsung.com > > Luis