Re: [PATCH 0/3] zsmalloc: small compaction improvements

Sergey Senozhatsky
2015-07-15T00:20:34Z

On (07/15/15 01:52), Minchan Kim wrote:
> > alrighty... again...
> >
> > > >
> > > > /sys/block/zram<id>/compact is a black box. We provide it, we don't
> > > > throttle it in the kernel, and user space is absolutely clueless when
> > > > it invokes compaction. From some remote (or alternative) point of
> > >
> > > But we have zs_can_compact so it can effectively skip the class if it
> > > is not proper class.
> >
> > user triggered compaction can compact too much.
> > in its current state triggering a compaction from user space is like
> > playing a lottery or a russian roulette.
>
> We were on different page.

> I thought the motivation from this patchset is to prevent compaction
> overhead by frequent user-driven compaction request because user
> don't know how they can get free pages by compaction so they should
> ask compact frequently with blind.

this is exactly the motivation for this patchset. seriously.

whatever.

-ss