From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx137.postini.com [74.125.245.137]) by kanga.kvack.org (Postfix) with SMTP id C88746B0044 for ; Mon, 2 Apr 2012 13:10:33 -0400 (EDT) Received: by ghrr18 with SMTP id r18so1685142ghr.14 for ; Mon, 02 Apr 2012 10:10:32 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <65795E11DBF1E645A09CEC7EAEE94B9C01454D13A6@USINDEVS02.corp.hds.com> References: <65795E11DBF1E645A09CEC7EAEE94B9CB9455FE2@USINDEVS02.corp.hds.com> <20120305215602.GA1693@redhat.com> <4F5798B1.5070005@jp.fujitsu.com> <65795E11DBF1E645A09CEC7EAEE94B9CB951A45F@USINDEVS02.corp.hds.com> <65795E11DBF1E645A09CEC7EAEE94B9C01454D13A6@USINDEVS02.corp.hds.com> From: KOSAKI Motohiro Date: Mon, 2 Apr 2012 10:10:12 -0700 Message-ID: Subject: Re: [RFC][PATCH] avoid swapping out with swappiness==0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Satoru Moriya Cc: "jweiner@redhat.com" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "riel@redhat.com" , "lwoodman@redhat.com" , "shaohua.li@intel.com" , "dle-develop@lists.sourceforge.net" , Seiji Aguchi 2012/3/30 Satoru Moriya : > Hello Kosaki-san, > > On 03/07/2012 01:18 PM, Satoru Moriya wrote: >> On 03/07/2012 12:19 PM, KOSAKI Motohiro wrote: >>> Thank you. I brought back to memory it. Unfortunately DB folks are >>> still mainly using RHEL5 generation distros. At that time, >>> swapiness=3D0 doesn't mean disabling swap. >>> >>> They want, "don't swap as far as kernel has any file cache page". but >>> linux don't have such feature. then they used swappiness for emulate >>> it. So, I think this patch clearly make userland harm. Because of, we >>> don't have an alternative way. > > As I wrote in the previous mail(see below), with this patch > the kernel begins to swap out when the sum of free pages and > filebacked pages reduces less than watermark_high. > > So the kernel reclaims pages like following. > > nr_free + nr_filebacked >=3D watermark_high: reclaim only filebacked page= s > nr_free + nr_filebacked < =A0watermark_high: reclaim only anonymous pages How? -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org