On Thu, May 05, 2016 at 07:03:29PM +0900, Sergey Senozhatsky wrote:
> On (05/05/16 13:17), Ganesh Mahendran wrote:
> > if we find a zspage with usage == 100%, there is no need to
> > try other zspages.
>
> Hello,
>
> well... we iterate there from 0 to 1<<2, which is not awfully
> a lot to break it in the middle, and we do this only when we
> initialize a new pool (for every size class).
>
> the check is
> - true 15 times
> - false 492 times
Thanks for the data, Sergey!
>
> so it _sort of_ feels like this new if-condition doesn't
> buy us a lot, and most of the time it just sits there with
> no particular gain. let's hear from Minchan.
>
I agree with Sergey.
First of al, I appreciates your patch, Ganesh! But as Sergey pointed
out, I don't see why it improves current zsmalloc.
If you want to merge strongly, please convince me with more detail
reason.
Thanks.
> -ss
>
> > Signed-off-by: Ganesh Mahendran <opensource.gan...@gmail.com>
> > Cc: Minchan Kim <minc...@kernel.org>
> > Cc: Nitin Gupta <ngu...@vflare.org>
> > Cc: Sergey Senozhatsky <sergey.senozhatsky.w...@gmail.com>
> > ---
> > mm/zsmalloc.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> > index fda7177..310c7b0 100644
> > --- a/mm/zsmalloc.c
> > +++ b/mm/zsmalloc.c
> > @@ -765,6 +765,9 @@ static int get_pages_per_zspage(int class_size)
> > if (usedpc > max_usedpc) {
> > max_usedpc = usedpc;
> > max_usedpc_order = i;
> > +
> > + if (max_usedpc == 100)
> > + break;
> > }
> > }
> >
> > --
> > 1.7.9.5
> >
