On Wed, Sep 4, 2024 at 8:08 AM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > On Tue, 3 Sep 2024 11:38:37 -0700 Yosry Ahmed <yosryahmed@xxxxxxxxxx> wrote: > > > > [ 39.157954] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000007 > > > [ 39.158288] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 > > > [ 39.158634] R13: 0000000000002b9a R14: 0000000000000000 R15: 00007ffd619d5518 > > > [ 39.158998] </TASK> > > > [ 39.159226] ---[ end trace 0000000000000000 ]--- > > > > > > After reverting this or Usama's "mm: store zero pages to be swapped > > > out in a bitmap", the problem is gone. I think these two patches may > > > have some conflict that needs to be resolved. > > > > Yup. I saw this conflict coming and specifically asked for this > > warning to be added in Usama's patch to catch it [1]. It served its > > purpose. > > > > Usama's patch does not handle large folio swapin, because at the time > > it was written we didn't have it. We expected Usama's series to land > > sooner than this one, so the warning was to make sure that this series > > handles large folio swapin in the zeromap code. Now that they are both > > in mm-unstable, we are gonna have to figure this out. > > > > I suspect Usama's patches are closer to land so it's better to handle > > this in this series, but I will leave it up to Usama and > > Chuanhua/Barry to figure this out :) I believe handling this in swap-in might violate layer separation. `swap_read_folio()` should be a reliable API to call, regardless of whether `zeromap` is present. Therefore, the fix should likely be within `zeromap` but not this `swap-in`. I’ll take a look at this with Usama :-) > > > > [1]https://lore.kernel.org/lkml/CAJD7tkbpXjg00CRSrXU_pbaHwEaW1b3k8AQgu8y2PAh7EkTOug@xxxxxxxxxxxxxx/ > > Thanks. To unbreak -next I'll drop the two-patch series "mm: Ignite > large folios swap-in support" for now. > > btw, next time can we please call it "enable large folios swap-in > support"? "ignite" doesn't make much sense here. sure. > Thanks Barry
