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From: Daniel Vetter <daniel@ffwll.ch>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Minchan Kim <minchan@kernel.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Vlastimil Babka <vbabka@suse.cz>,
	dri-devel@lists.freedesktop.org, Hugh Dickins <hughd@google.com>,
	John Einar Reitan <john.reitan@foss.arm.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Konstantin Khlebnikov <koct9i@gmail.com>,
	Mel Gorman <mgorman@suse.de>,
	Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
	Rafael Aquini <aquini@redhat.com>, Rik van Riel <riel@redhat.com>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	virtualization@lists.linux-foundation.org,
	Gioh Kim <gi-oh.kim@profitbricks.com>,
	Chan Gyun Jeong <chan.jeong@lge.com>,
	Sangseok Lee <sangseok.lee@lge.com>,
	Kyeongdon Kim <kyeongdon.kim@lge.com>,
	Chulmin Kim <cmlaika.kim@samsung.com>
Subject: Re: [PATCH v7 00/12] Support non-lru page migration
Date: Thu, 2 Jun 2016 00:40:11 +0200
Message-ID: <20160601224011.GC7231@phenom.ffwll.local> (raw)
In-Reply-To: <20160601144151.c9e5c560be29cae9a3ff1f1e@linux-foundation.org>

On Wed, Jun 01, 2016 at 02:41:51PM -0700, Andrew Morton wrote:
> On Wed,  1 Jun 2016 08:21:09 +0900 Minchan Kim <minchan@kernel.org> wrote:
> 
> > Recently, I got many reports about perfermance degradation in embedded
> > system(Android mobile phone, webOS TV and so on) and easy fork fail.
> > 
> > The problem was fragmentation caused by zram and GPU driver mainly.
> > With memory pressure, their pages were spread out all of pageblock and
> > it cannot be migrated with current compaction algorithm which supports
> > only LRU pages. In the end, compaction cannot work well so reclaimer
> > shrinks all of working set pages. It made system very slow and even to
> > fail to fork easily which requires order-[2 or 3] allocations.
> > 
> > Other pain point is that they cannot use CMA memory space so when OOM
> > kill happens, I can see many free pages in CMA area, which is not
> > memory efficient. In our product which has big CMA memory, it reclaims
> > zones too exccessively to allocate GPU and zram page although there are
> > lots of free space in CMA so system becomes very slow easily.
> 
> But this isn't presently implemented for GPU drivers or for CMA, yes?
> 
> What's the story there?

Broken (out-of-tree) drivers that don't allocate their gpu stuff
correctly.  There's piles of drivers that get_user_page all over the place
but then fail to timely get off these pages again. The fix is to get off
those pages again (either by unpinning timely, or registering an
mmu_notifier if the driver wants to keep the pages pinned indefinitely, as
a caching optimization).

At least that's my guess, and iirc it was confirmed first time around this
series showed up.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

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Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-31 23:21 Minchan Kim
2016-05-31 23:21 ` [PATCH v7 01/12] mm: use put_page to free page instead of putback_lru_page Minchan Kim
2016-05-31 23:21 ` [PATCH v7 02/12] mm: migrate: support non-lru movable page migration Minchan Kim
2016-05-31 23:21 ` [PATCH v7 03/12] mm: balloon: use general non-lru movable page feature Minchan Kim
2016-05-31 23:21 ` [PATCH v7 04/12] zsmalloc: keep max_object in size_class Minchan Kim
2016-05-31 23:21 ` [PATCH v7 05/12] zsmalloc: use bit_spin_lock Minchan Kim
2016-05-31 23:21 ` [PATCH v7 06/12] zsmalloc: use accessor Minchan Kim
2016-05-31 23:21 ` [PATCH v7 07/12] zsmalloc: factor page chain functionality out Minchan Kim
2016-05-31 23:21 ` [PATCH v7 08/12] zsmalloc: introduce zspage structure Minchan Kim
2016-05-31 23:21 ` [PATCH v7 09/12] zsmalloc: separate free_zspage from putback_zspage Minchan Kim
2016-05-31 23:21 ` [PATCH v7 10/12] zsmalloc: use freeobj for index Minchan Kim
2016-05-31 23:21 ` [PATCH v7 11/12] zsmalloc: page migration support Minchan Kim
2016-06-01 14:09   ` Vlastimil Babka
2016-06-02  0:25     ` Minchan Kim
2016-06-02 11:44       ` Vlastimil Babka
2016-06-01 21:39   ` Andrew Morton
2016-06-02  0:15     ` Minchan Kim
     [not found]   ` <CGME20170119001317epcas1p188357c77e1f4ff08b6d3dcb76dedca06@epcas1p1.samsung.com>
2017-01-19  0:13     ` Chulmin Kim
2017-01-19  2:44       ` Minchan Kim
2017-01-19  3:39         ` Chulmin Kim
2017-01-19  6:21           ` Minchan Kim
2017-01-19  8:16             ` Chulmin Kim
2017-01-23  5:22               ` Minchan Kim
2017-01-23  5:30                 ` Sergey Senozhatsky
2017-01-23  5:40                   ` Minchan Kim
2017-01-25  4:06                     ` Chulmin Kim
2017-01-25  4:25                       ` Sergey Senozhatsky
2017-01-25  5:26                       ` Minchan Kim
2017-01-26 17:04                         ` Dan Streetman
2017-01-31  0:10                           ` Minchan Kim
2017-01-31 13:09                             ` Dan Streetman
2017-02-01  6:51                               ` Minchan Kim
2017-02-01 19:38                                 ` Dan Streetman
2017-02-02  8:48                               ` Minchan Kim
2016-05-31 23:21 ` [PATCH v7 12/12] zram: use __GFP_MOVABLE for memory allocation Minchan Kim
2016-06-01 21:41 ` [PATCH v7 00/12] Support non-lru page migration Andrew Morton
2016-06-01 22:40   ` Daniel Vetter [this message]
2016-06-02  0:36   ` Minchan Kim
2016-06-15  7:59 ` Sergey Senozhatsky
2016-06-15 23:12   ` Minchan Kim
2016-06-16  2:48     ` Sergey Senozhatsky
2016-06-16  2:58       ` Minchan Kim
2016-06-16  4:23         ` Sergey Senozhatsky
2016-06-16  4:47           ` Minchan Kim
2016-06-16  5:22             ` Sergey Senozhatsky
2016-06-16  6:47               ` Minchan Kim
2016-06-16  8:42                 ` Sergey Senozhatsky
2016-06-16 10:09                   ` Minchan Kim
2016-06-17  7:28                     ` Joonsoo Kim

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