From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by wa-out-1112.google.com with SMTP id j37so1368485waf.22 for ; Sun, 16 Nov 2008 22:39:20 -0800 (PST) Message-ID: <2f11576a0811162239w58555c6dq8a61ec184b22bd52@mail.gmail.com> Date: Mon, 17 Nov 2008 15:39:20 +0900 From: "KOSAKI Motohiro" Subject: Re: [PATCH] mm: evict streaming IO cache first In-Reply-To: <20081117153012.51ece88f.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20081115181748.3410.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20081115210039.537f59f5.akpm@linux-foundation.org> <49208E9A.5080801@redhat.com> <20081116204720.1b8cbe18.akpm@linux-foundation.org> <20081117153012.51ece88f.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: Andrew Morton , Rik van Riel , Linus Torvalds , LKML , linux-mm , Gene Heskett List-ID: 2008/11/17 KAMEZAWA Hiroyuki : > On Sun, 16 Nov 2008 20:47:20 -0800 > Andrew Morton wrote: > >> On Sun, 16 Nov 2008 16:20:26 -0500 Rik van Riel wrote: >> Anyway, we need to do something. >> >> Shouldn't get_scan_ratio() be handling this case already? >> > Hmm, could I make a question ? > > I think > > - recent_rolated[LRU_FILE] is incremented when file cache is moved from > ACTIVE_FILE to INACTIVE_FILE. > - recent_scanned[LRU_FILE] is sum of scanning numbers on INACTIVE/ACTIVE list > of file. > - file caches are added to INACITVE_FILE, at first. > - get_scan_ratio() calculates %file to be > > file recent rotated. > %file = IO_cost * ------------ / ------------- > anon + file recent scanned. rewote by div to mul changing. file recent scanned. %file = IO_cost * ------------ * ------------- anon + file recent rotated. > But when "files are used by streaming or some touch once application", > there is no rotation because they are in INACTIVE FILE at first add_to_lru(). > But recent_rotated will not increase while recent_scanned goes bigger and bigger. Yup. > Then %file goes to 0 rapidly. I think reverse. The problem is, when streaming access started right after, recent scanned isn't so much. then %file don't reach 100%. then, few anon pages swaped out althouth memory pressure isn't so heavy. -- 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