Re: [PATCH] psi: Treat ksm swapping in copy as memstall

From: CGEL
Date: Fri Jan 21 2022 - 04:51:14 EST


Wed, Jan 19, 2022 at 07:58:23AM -0500, Johannes Weiner wrote:
> On Wed, Jan 19, 2022 at 06:13:54AM +0000, CGEL wrote:
> > I did a test, when we use zram, it takes longer time for ksm copying than
> > swap_readpage(). Ksm copying average takes 147263ns, swap_readpage()
> > average takes 55639ns. So I think this patch is reasonable.
>
> Ok, that sounds reasonable to me as well. Please add the
> PageWorkingset() check and resubmit the patch. Thanks!
I am a litte confused about adding PageWorkingset(), since I
think ksm_might_need_to_copy() memstall is like swap_readpage()
memstall and swap_readpage() doesn't add PageWorkingset().

Would please make it cleaner? Thanks!