Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1463439
| Path | csiph.com!goblin2!goblin.stu.neva.ru!news.unit0.net!news.mixmin.net!aioe.org!bofh.it!news.nic.it!robomod |
|---|---|
| From | Vlastimil Babka <vbabka@suse.cz> |
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v6 04/11] mm, compaction: don't recheck watermarks after COMPACT_SUCCESS |
| Date | Tue, 16 Aug 2016 08:20:02 +0200 |
| Message-ID | <s6FTc-7TO-21@gated-at.bofh.it> (permalink) |
| References | <s4GgI-79-119@gated-at.bofh.it> <s4Jez-29X-49@gated-at.bofh.it> <s6FJw-7Qq-23@gated-at.bofh.it> |
| X-Original-To | Joonsoo Kim <iamjoonsoo.kim@lge.com> |
| User-Agent | Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2 |
| MIME-Version | 1.0 |
| Content-Type | text/plain; charset=windows-1252; format=flowed |
| Content-Transfer-Encoding | 7bit |
| Sender | robomod@news.nic.it |
| List-ID | <linux-kernel.vger.kernel.org> |
| X-Mailing-List | linux-kernel@vger.kernel.org |
| Approved | robomod@news.nic.it |
| Lines | 25 |
| Organization | linux.* mail to news gateway |
| X-Original-Cc | Andrew Morton <akpm@linux-foundation.org>, Michal Hocko <mhocko@kernel.org>, Mel Gorman <mgorman@techsingularity.net>, David Rientjes <rientjes@google.com>, Rik van Riel <riel@redhat.com>, linux-mm@kvack.org, linux-kernel@vger.kernel.org |
| X-Original-Date | Tue, 16 Aug 2016 08:11:21 +0200 |
| X-Original-Message-ID | <7cd558df-d815-2e05-6a24-d1e1c87f184f@suse.cz> |
| X-Original-References | <20160810091226.6709-1-vbabka@suse.cz> <20160810091226.6709-5-vbabka@suse.cz> <20160816061200.GD17448@js1304-P5Q-DELUXE> |
| X-Original-Sender | linux-kernel-owner@vger.kernel.org |
| Xref | csiph.com linux.kernel:1463439 |
Show key headers only | View raw
On 08/16/2016 08:12 AM, Joonsoo Kim wrote: > On Wed, Aug 10, 2016 at 11:12:19AM +0200, Vlastimil Babka wrote: >> Joonsoo has reminded me that in a later patch changing watermark checks >> throughout compaction I forgot to update checks in try_to_compact_pages() and >> compactd_do_work(). Closer inspection however shows that they are redundant now >> that compact_zone() reliably reports success with COMPACT_SUCCESS, as they just >> repeat (a subset) of checks that have just passed. So instead of checking >> watermarks again, just test the return value. > > In fact, it's not redundant. Even if try_to_compact_pages() returns > !COMPACT_SUCCESS, watermark check could return true. Right, I meant they are redundant in the SUCCESS case. > __compact_finished() calls find_suitable_fallback() and it's slightly > different with watermark check. Anyway, I don't think it is a big > problem. I agree. It might be even better for long-term fragmentation that we e.g. try another zone instead of taking page from the "unsuitable fallback". If that's not successful, and the allocation is important enough there will later eventually be another watermark check permitting the unsuitable fallback. Thanks.
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Re: [PATCH v6 04/11] mm, compaction: don't recheck watermarks after COMPACT_SUCCESS Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-08-16 08:10 +0200 Re: [PATCH v6 04/11] mm, compaction: don't recheck watermarks after COMPACT_SUCCESS Vlastimil Babka <vbabka@suse.cz> - 2016-08-16 08:20 +0200 Re: [PATCH v6 04/11] mm, compaction: don't recheck watermarks after COMPACT_SUCCESS Vlastimil Babka <vbabka@suse.cz> - 2016-08-18 14:00 +0200
csiph-web