Re: [RFC][PATCHv3 3/7] zsmalloc: always keep per-class stats

Sergey Senozhatsky
2015-06-29T09:06:35Z

On (06/29/15 15:40), Minchan Kim wrote:
> On Thu, Jun 18, 2015 at 08:46:40PM +0900, Sergey Senozhatsky wrote:
> > Always account per-class `zs_size_stat' stats. This data will
> > help us make better decisions during compaction. We are especially
> > interested in OBJ_ALLOCATED and OBJ_USED, which can tell us if
> > class compaction will result in any memory gain.
> >
> > For instance, we know the number of allocated objects in the class,
> > the number of objects being used (so we also know how many objects
> > are not used) and the number of objects per-page. So we can ensure
> > if we have enough unused objects to form at least one ZS_EMPTY
> > zspage during compaction.
> >
> > We calculate this value on per-class basis so we can calculate a
> > total number of zspages that can be released. Which is exactly what
> > a shrinker wants to know.
> >
> > Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> Acked-by: Minchan Kim <minchan@kernel.org>
>

thanks.

-ss