Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755799AbXE1Lnv (ORCPT ); Mon, 28 May 2007 07:43:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750760AbXE1Lno (ORCPT ); Mon, 28 May 2007 07:43:44 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:40759 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750730AbXE1Lnn (ORCPT ); Mon, 28 May 2007 07:43:43 -0400 Message-ID: <465AC05A.80005@hitachi.com> Date: Mon, 28 May 2007 20:43:22 +0900 From: "Kawai, Hidehiro" User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; ja-JP; rv:1.4) Gecko/20030624 Netscape/7.1 (ax) X-Accept-Language: ja MIME-Version: 1.0 To: Randy Dunlap Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, dhowells@redhat.com, holt@sgi.com, alan@lxorguk.ukuu.org.uk, masami.hiramatsu.pt@hitachi.com, yumiko.sugita.yf@hitachi.com, soshima@redhat.com, haoki@redhat.com Subject: Re: [PATCH 7/7] documentation for /proc/pid/coredump_filter References: <4656DBFB.2050501@hitachi.com> <4656E0D7.1090301@hitachi.com> <20070527181729.e9e6d57c.randy.dunlap@oracle.com> In-Reply-To: <20070527181729.e9e6d57c.randy.dunlap@oracle.com> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3861 Lines: 95 Hi Randy, Randy Dunlap wrote: > Looks good. Just one typo below. > > ------------------------------------------------------------------------------ > >> Preface >>@@ -2135,4 +2136,41 @@ those 64-bit counters, process A could s >> More information about this can be found within the taskstats documentation in >> Documentation/accounting. >> >>+2.15 /proc//coredump_filter - Core dump filtering settings >>+--------------------------------------------------------------- >>+When a process is dumped, all anonymous memory is written to a core file as >>+long as the size of the core file isn't limited. But sometimes we don't want >>+to dump some memory segments, for example, huge shared memory. Conversely, >>+sometimes we wnat to save file-backed memory segments into a core file, not > > want Thank you for your review. I attached the fixed patch. Best regards, -- Hidehiro Kawai Hitachi, Ltd., Systems Development Laboratory Signed-off-by: Hidehiro Kawai --- Documentation/filesystems/proc.txt | 38 +++++++++++++++++++++++++++ 1 files changed, 38 insertions(+) Index: linux-2.6.22-rc2-mm1/Documentation/filesystems/proc.txt =================================================================== --- linux-2.6.22-rc2-mm1.orig/Documentation/filesystems/proc.txt +++ linux-2.6.22-rc2-mm1/Documentation/filesystems/proc.txt @@ -42,6 +42,7 @@ Table of Contents 2.12 /proc//oom_adj - Adjust the oom-killer score 2.13 /proc//oom_score - Display current oom-killer score 2.14 /proc//io - Display the IO accounting fields + 2.15 /proc//coredump_filter - Core dump filtering settings ------------------------------------------------------------------------------ Preface @@ -2135,4 +2136,41 @@ those 64-bit counters, process A could s More information about this can be found within the taskstats documentation in Documentation/accounting. +2.15 /proc//coredump_filter - Core dump filtering settings +--------------------------------------------------------------- +When a process is dumped, all anonymous memory is written to a core file as +long as the size of the core file isn't limited. But sometimes we don't want +to dump some memory segments, for example, huge shared memory. Conversely, +sometimes we want to save file-backed memory segments into a core file, not +only the individual files. + +/proc//coredump_filter allows you to customize which memory segments +will be dumped when the process is dumped. coredump_filter is a bitmask +of memory types. If a bit of the bitmask is set, memory segments of the +corresponding memory type are dumped, otherwise they are not dumped. + +The following 4 memory types are supported: + - (bit 0) anonymous private memory + - (bit 1) anonymous shared memory + - (bit 2) file-backed private memory + - (bit 3) file-backed shared memory + + Note that MMIO pages such as frame buffer are never dumped and vDSO pages + are always dumped regardless of the bitmask status. + +Default value of coredump_filter is 0x3; this means all anonymous memory +segments are dumped. + +If you don't want to dump all shared memory segments attached to pid 1234, +write 1 to the process's proc file. + + $ echo 0x1 > /proc/1234/coredump_filter + +When a new process is created, the process inherits the bitmask status from its +parent. It is useful to set up coredump_filter before the program runs. +For example: + + $ echo 0x7 > /proc/self/coredump_filter + $ ./some_program + ------------------------------------------------------------------------------ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/