On Wed, Mar 09, 2022 at 02:18:19PM -0500, Johannes Weiner wrote:
> On Wed, Mar 09, 2022 at 09:43:24AM +0000, cgel.zte@xxxxxxxxx wrote:
> > From: Yang Yang <yang.yang29@xxxxxxxxxx>
> >
> > psi tracks the time spent submitting the IO of refaulting pages[1].
> > But after we tracks refault stalls from swap_readpage[2][3], there
> > is no need to do so anymore. Since swap_readpage already includes
> > IO submitting time.
> >
> > [1] commit b8e24a9300b0 ("block: annotate refault stalls from IO submission")
> > [2] commit 937790699be9 ("mm/page_io.c: annotate refault stalls from swap_readpage")
> > [3] commit 2b413a1a728f ("mm: page_io: fix psi memory pressure error on cold swapins")
> >
> > Signed-off-by: Yang Yang <yang.yang29@xxxxxxxxxx>
> > Reviewed-by: Ran Xiaokai <ran.xiaokai@xxxxxxxxxx>
>
> It's still needed by file cache refaults!
>
> NAK
What about submit_bio() only counts file cache refaults?
This will reduce redundant calling of psi_memstall_enter()
for swap_readpage().
