From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 15 Oct 2008 23:06:59 -0700 From: Andrew Morton Subject: Re: mm-more-likely-reclaim-madv_sequential-mappings.patch Message-Id: <20081015230659.a717d0b6.akpm@linux-foundation.org> In-Reply-To: <20081016143830.582C.KOSAKI.MOTOHIRO@jp.fujitsu.com> References: <20081015162232.f673fa59.akpm@linux-foundation.org> <20081016102752.9886.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20081016143830.582C.KOSAKI.MOTOHIRO@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KOSAKI Motohiro Cc: linux-mm@kvack.org, Johannes Weiner List-ID: On Thu, 16 Oct 2008 15:01:01 +0900 (JST) KOSAKI Motohiro wrote: > > > I have a note here that this patch needs better justification. But the > > > changelog looks good and there are pretty graphs, so maybe my note is stale. > > > > > > Can people please check it? > > > > > > Thanks. > > > > maybe, I can run benchmark it. > > please wait few hour. Thanks, it really helps. > 1. mesured various copy performance. > using copybench -> http://code.google.com/p/copybench/ > > my machine mem: 8GB > target file size: 10GB (filesize > system mem) > > > 2.6.27 mmotm-1010: > ============================================================== > rw_cp 6:13 6:11 > rw_fadv_cp 6:09 6:06 > mm_sync_cp 5:51 5:55 > mm_sync_madv_cp 5:59 5:57 > mw_cp 5:50 5:50 > mw_madv_cp 5:55 5:55 > > > So, no improvement, but no regression. > > > 2. Latency degression ratio of Sequential copy v.s. Other I/O situation > > run following script (mm_sync_madv_cp is one of copybench program) > > $ dbench -D /disk2/ -c client.txt 100 & > $ sleep 100 > $ time ./mm_sync_madv_cp src dst > > > 2.6.27 mmotm-1010 > ============================================================== > mm_sync_madv_cp 6:14 6:02 (min:sec) > dbench throughput 12.1507 14.6273 (MB/s) > dbench latency 33046 21779 (ms) > > > So, throughput improvement is relativily a bit, but latency improvement is much. > Then, I think the patch can improve "larege file copy (e.g. backup operation) > attacks desktop latency" problem. > > Any comments? > Sounds good. But how do we know that it was this particular patch which improved the latency performance? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org