Re: [PATCH] mm: extend zero pages to same element pages for zram

From: Sergey Senozhatsky
Date: Tue Jan 24 2017 - 23:18:49 EST


On (01/24/17 18:48), Matthew Wilcox wrote:
> On Wed, Jan 25, 2017 at 10:32:44AM +0900, Sergey Senozhatsky wrote:
> > Hello,
> >
> > On (01/25/17 10:29), Minchan Kim wrote:
> > [..]
> > > > the result as listed below:
> > > >
> > > > zero pattern_char pattern_short pattern_int pattern_long total (unit)
> > > > 162989 14454 3534 23516 2769 3294399 (page)
> > > >
> > >
> > > so, int covers 93%. As considering non-zero dedup hit ratio is low, I think *int* is
> > > enough if memset is really fast. So, I'd like to go with 'int' if Sergey doesn't mind.
> >
> > yep, 4 byte pattern matching and memset() sounds like a good plan to me
>
> what? memset ONLY HANDLES BYTES.
>
> I pointed this out earlier, but you don't seem to be listening. Let me
> try it again.
>
> MEMSET ONLY HANDLES BYTES.

dammit... how did that happen...


Matthew, you are absolute right. and, yes, I missed out your previous
mail, indeed. sorry. and thanks for "re-pointing" that out.


Minchan, zhouxianrong, I was completely wrong. we can't
do memset(). d'oh, I did not know it truncates 4 bytes to
one byte only (doesn't make too much sense to me).

my apologies.

-ss