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

From	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 0/3] zsmalloc: small compaction improvements
Date	2015-07-15 13:20 +0200
Message-ID	<pMsTg-5QQ-13@gated-at.bofh.it> (permalink)
References	(3 earlier) <pLWJH-3Ps-5@gated-at.bofh.it> <pM7F8-29U-7@gated-at.bofh.it> <pMbIJ-67X-3@gated-at.bofh.it> <pMiKe-81q-9@gated-at.bofh.it> <pMiKe-81q-7@gated-at.bofh.it>
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On (07/15/15 09:24), Minchan Kim wrote:
> On Wed, Jul 15, 2015 at 09:21:06AM +0900, Sergey Senozhatsky wrote:
> > 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.
> 
> User should rely on the auto-compaction.

yep, which will be available in 5-6 months... right behind the corner.

	-ss
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Thread

[PATCH 0/3] zsmalloc: small compaction improvements Sergey Senozhatsky <sergey.senozhatsky@gmail.com> - 2015-07-11 11:50 +0200
  [PATCH 1/3] zsmalloc: factor out zs_pages_to_compact() Sergey Senozhatsky <sergey.senozhatsky@gmail.com> - 2015-07-11 11:50 +0200
  [PATCH 3/3] zsmalloc: do not take class lock in zs_pages_to_compact() Sergey Senozhatsky <sergey.senozhatsky@gmail.com> - 2015-07-11 11:50 +0200
  [PATCH 2/3] zram: make compact a read-write sysfs node Sergey Senozhatsky <sergey.senozhatsky@gmail.com> - 2015-07-11 11:50 +0200
  Re: [PATCH 0/3] zsmalloc: small compaction improvements Minchan Kim <minchan@kernel.org> - 2015-07-15 02:30 +0200
    Re: [PATCH 0/3] zsmalloc: small compaction improvements Sergey Senozhatsky <sergey.senozhatsky@gmail.com> - 2015-07-15 13:20 +0200
  Re: [PATCH 0/3] zsmalloc: small compaction improvements Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2015-07-15 02:30 +0200

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