From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx159.postini.com [74.125.245.159]) by kanga.kvack.org (Postfix) with SMTP id 8877A6B0062 for ; Mon, 8 Apr 2013 13:35:14 -0400 (EDT) Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 8 Apr 2013 13:35:13 -0400 Received: from d01relay07.pok.ibm.com (d01relay07.pok.ibm.com [9.56.227.147]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 42D3738C806A for ; Mon, 8 Apr 2013 13:35:11 -0400 (EDT) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay07.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r38HZ8uv51839154 for ; Mon, 8 Apr 2013 13:35:08 -0400 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r38HZ8ii032564 for ; Mon, 8 Apr 2013 13:35:08 -0400 Message-ID: <5162FFB2.9010201@linux.vnet.ibm.com> Date: Mon, 08 Apr 2013 10:34:42 -0700 From: Cody P Schafer MIME-Version: 1.0 Subject: Re: [PATCH 3/3] mm: when handling percpu_pagelist_fraction, use on_each_cpu() to set percpu pageset fields. References: <1365194030-28939-1-git-send-email-cody@linux.vnet.ibm.com> <1365194030-28939-4-git-send-email-cody@linux.vnet.ibm.com> <5160D242.4010404@gmail.com> In-Reply-To: <5160D242.4010404@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Simon Jeons Cc: Andrew Morton , Mel Gorman , Linux MM , LKML On 04/06/2013 06:56 PM, Simon Jeons wrote: > Hi Cody, > On 04/06/2013 04:33 AM, Cody P Schafer wrote: >> In free_hot_cold_page(), we rely on pcp->batch remaining stable. >> Updating it without being on the cpu owning the percpu pageset >> potentially destroys this stability. > > If cpu is off, can its pcp pageset be used in free_hot_code_page()? > I don't expect it to be as we use this_cpu_ptr() to access the pcp pageset. Unless there is some crazy mode where we can override the cpu a task believes it is running on... -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935188Ab3DHRfY (ORCPT ); Mon, 8 Apr 2013 13:35:24 -0400 Received: from e8.ny.us.ibm.com ([32.97.182.138]:51664 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763332Ab3DHRfX (ORCPT ); Mon, 8 Apr 2013 13:35:23 -0400 Message-ID: <5162FFB2.9010201@linux.vnet.ibm.com> Date: Mon, 08 Apr 2013 10:34:42 -0700 From: Cody P Schafer User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: Simon Jeons CC: Andrew Morton , Mel Gorman , Linux MM , LKML Subject: Re: [PATCH 3/3] mm: when handling percpu_pagelist_fraction, use on_each_cpu() to set percpu pageset fields. References: <1365194030-28939-1-git-send-email-cody@linux.vnet.ibm.com> <1365194030-28939-4-git-send-email-cody@linux.vnet.ibm.com> <5160D242.4010404@gmail.com> In-Reply-To: <5160D242.4010404@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13040817-9360-0000-0000-000011A57CCD Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/06/2013 06:56 PM, Simon Jeons wrote: > Hi Cody, > On 04/06/2013 04:33 AM, Cody P Schafer wrote: >> In free_hot_cold_page(), we rely on pcp->batch remaining stable. >> Updating it without being on the cpu owning the percpu pageset >> potentially destroys this stability. > > If cpu is off, can its pcp pageset be used in free_hot_code_page()? > I don't expect it to be as we use this_cpu_ptr() to access the pcp pageset. Unless there is some crazy mode where we can override the cpu a task believes it is running on...