From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752620Ab2DUAVy (ORCPT ); Fri, 20 Apr 2012 20:21:54 -0400 Received: from usindpps03.hds.com ([207.126.252.16]:50069 "EHLO usindpps03.hds.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751147Ab2DUAVw convert rfc822-to-8bit (ORCPT ); Fri, 20 Apr 2012 20:21:52 -0400 From: Satoru Moriya To: KOSAKI Motohiro , Jerome Marchand CC: KOSAKI Motohiro , "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 Date: Fri, 20 Apr 2012 20:21:28 -0400 Subject: RE: [RFC][PATCH] avoid swapping out with swappiness==0 Thread-Topic: [RFC][PATCH] avoid swapping out with swappiness==0 Thread-Index: Ac0SibtX7j/6MI5MS9Ch6BlzO39vIQMyoA0g Message-ID: <65795E11DBF1E645A09CEC7EAEE94B9C014575D8CF@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> <4F7ADE1A.2050004@redhat.com> <4F7C870B.6020807@gmail.com> In-Reply-To: <4F7C870B.6020807@gmail.com> Accept-Language: ja-JP, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: ja-JP, en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-Proofpoint-Spam-Details: rule=outbound_policy_notspam policy=outbound_policy score=0 spamscore=0 ipscore=0 suspectscore=5 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=6.0.2-1203120001 definitions=main-1204200317 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Sorry for my late reply. On 04/04/2012 01:38 PM, KOSAKI Motohiro wrote: > (4/3/12 4:25 AM), Jerome Marchand wrote: >> On 04/02/2012 07:10 PM, KOSAKI Motohiro wrote: >>> 2012/3/30 Satoru Moriya: >>>> So the kernel reclaims pages like following. >>>> >>>> nr_free + nr_filebacked>= watermark_high: reclaim only filebacked pages >>>> nr_free + nr_filebacked< watermark_high: reclaim only anonymous pages >>> >>> How? >> >> get_scan_count() checks that case explicitly: >> >> if (global_reclaim(sc)) { >> free = zone_page_state(mz->zone, NR_FREE_PAGES); >> /* If we have very few page cache pages, >> force-scan anon pages. */ >> if (unlikely(file + free<= high_wmark_pages(mz->zone))) { >> fraction[0] = 1; >> fraction[1] = 0; >> denominator = 1; >> goto out; >> } >> } > > Eek. This is silly. Nowaday many people enabled THP and it increase zone watermark. > so, high watermask is not good threshold anymore. Ah yes, it is not so small now. On 4GB server, without THP min_free_kbytes is 8113 but with THP it is 67584. How about using low watermark or min watermark? Are they still big? ...or should we use other value? Regards, Satoru From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx167.postini.com [74.125.245.167]) by kanga.kvack.org (Postfix) with SMTP id 25C996B004D for ; Fri, 20 Apr 2012 20:21:40 -0400 (EDT) From: Satoru Moriya Date: Fri, 20 Apr 2012 20:21:28 -0400 Subject: RE: [RFC][PATCH] avoid swapping out with swappiness==0 Message-ID: <65795E11DBF1E645A09CEC7EAEE94B9C014575D8CF@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> <4F7ADE1A.2050004@redhat.com> <4F7C870B.6020807@gmail.com> In-Reply-To: <4F7C870B.6020807@gmail.com> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: KOSAKI Motohiro , Jerome Marchand Cc: KOSAKI Motohiro , "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 Hi, Sorry for my late reply. On 04/04/2012 01:38 PM, KOSAKI Motohiro wrote: > (4/3/12 4:25 AM), Jerome Marchand wrote: >> On 04/02/2012 07:10 PM, KOSAKI Motohiro wrote: >>> 2012/3/30 Satoru Moriya: >>>> So the kernel reclaims pages like following. >>>> >>>> nr_free + nr_filebacked>=3D watermark_high: reclaim only filebacked pa= ges >>>> nr_free + nr_filebacked< watermark_high: reclaim only anonymous page= s >>> >>> How? >> >> get_scan_count() checks that case explicitly: >> >> if (global_reclaim(sc)) { >> free =3D zone_page_state(mz->zone, NR_FREE_PAGES); >> /* If we have very few page cache pages, >> force-scan anon pages. */ >> if (unlikely(file + free<=3D high_wmark_pages(mz->zone))) { >> fraction[0] =3D 1; >> fraction[1] =3D 0; >> denominator =3D 1; >> goto out; >> } >> } >=20 > Eek. This is silly. Nowaday many people enabled THP and it increase zone = watermark. > so, high watermask is not good threshold anymore. Ah yes, it is not so small now. On 4GB server, without THP min_free_kbytes is 8113 but with THP it is 67584. How about using low watermark or min watermark? Are they still big? ...or should we use other value?=20 Regards, Satoru -- 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