From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [patch] mm: more likely reclaim MADV_SEQUENTIAL mappings II References: <878wsigp2e.fsf_-_@saeurebad.de> <87zlkuj10z.fsf@saeurebad.de> <20081024213527.492B.KOSAKI.MOTOHIRO@jp.fujitsu.com> <4901DC5E.5040908@redhat.com> <87myguhsv4.fsf@saeurebad.de> Date: Sat, 25 Oct 2008 01:48:21 +0200 In-Reply-To: <87myguhsv4.fsf@saeurebad.de> (Johannes Weiner's message of "Fri, 24 Oct 2008 18:15:27 +0200") Message-ID: <87fxmlimgq.fsf@saeurebad.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: Linux MM Mailing List Cc: Rik van Riel , KOSAKI Motohiro , Andrew Morton , Nick Piggin List-ID: Johannes Weiner writes: > Rik van Riel writes: > >> KOSAKI Motohiro wrote: >>>> mmotm: >>>> normal user: 1.775000s [0.053307] system: 9.620000s [0.135339] total: 98.875000s [0.613956] >>>> madvise user: 2.552500s [0.041307] system: 9.442500s [0.075980] total: 73.937500s [0.734170] >>>> mmotm+patch: >>>> normal user: 1.850000s [0.013540] system: 9.760000s [0.047081] total: 99.250000s [0.569386] >>>> madvise user: 2.547500s [0.014930] system: 8.865000s [0.055000] total: 71.897500s [0.144763] >>>> >>>> Well, time-wise not sooo much of an improvement. But given the >>>> massively decreased LRU-rotation [ http://hannes.saeurebad.de/madvseq/ ] >>> >>> My first impression, this result mean the patch is not so useful. >>> But anyway, I mesured it again because I think Nick's opinion is very >>> reasonable and I don't know your mesurement condition so detail. >> >> It may not make much of a difference if the MADV_SEQUENTIAL >> program is the only thing running on the system. > > As said, I had a big dd running in the background. The box has only > 768mb RAM, so there really was VM activity going on. > > And given this small standard deviations, the numbers seem pretty > stable. Even if I had taken more samples, I highly doubt that they > would have looked much different. > > Perhaps still not enough VM pressure... Okay, Rik was kind enough to explain me what was wrong about my approach on IRC. Yes, the benchmark pretty much missed the point. Please ignore. Hannes -- 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