From: "Kawai, Hidehiro" <hidehiro.kawai.ez@hitachi.com>
To: Andrew Morton <akpm@osdl.org>,
kernel list <linux-kernel@vger.kernel.org>
Cc: "Kawai, Hidehiro" <hidehiro.kawai.ez@hitachi.com>,
Pavel Machek <pavel@ucw.cz>, Robin Holt <holt@sgi.com>,
dhowells@redhat.com, Alan Cox <alan@lxorguk.ukuu.org.uk>,
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
sugita <yumiko.sugita.yf@hitachi.com>,
Satoshi OSHIMA <soshima@redhat.com>,
"Hideo AOKI@redhat" <haoki@redhat.com>
Subject: [PATCH 4/4] coredump: documentation for proc entry
Date: Fri, 16 Feb 2007 22:42:25 +0900 [thread overview]
Message-ID: <45D5B4C1.7050306@hitachi.com> (raw)
In-Reply-To: <45D5B2E3.3030607@hitachi.com>
This patch adds the documentation for
/proc/<pid>/coredump_omit_anonymous_shared.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
---
Documentation/filesystems/proc.txt | 38 +++++++++++++++++++++++++++
1 files changed, 38 insertions(+)
Index: linux-2.6.20-mm1/Documentation/filesystems/proc.txt
===================================================================
--- linux-2.6.20-mm1.orig/Documentation/filesystems/proc.txt
+++ linux-2.6.20-mm1/Documentation/filesystems/proc.txt
@@ -41,6 +41,7 @@ Table of Contents
2.11 /proc/sys/fs/mqueue - POSIX message queues filesystem
2.12 /proc/<pid>/oom_adj - Adjust the oom-killer score
2.13 /proc/<pid>/oom_score - Display current oom-killer score
+ 2.14 /proc/<pid>/coredump_omit_anonymous_shared - Core dump coordinator
------------------------------------------------------------------------------
Preface
@@ -1982,6 +1983,43 @@ This file can be used to check the curre
any given <pid>. Use it together with /proc/<pid>/oom_adj to tune which
process should be killed in an out-of-memory situation.
+2.14 /proc/<pid>/coredump_omit_anonymous_shared - Core dump coordinator
+---------------------------------------------------------------------
+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.
+
+The /proc/<pid>/coredump_omit_anonymous_shared is a flag which enables you to
+omit anonymous shared memory segments from a core file when it is generated.
+When the <pid> process is dumped, the core dump routine decides whether a
+given memory segment should be dumped into a core file or not based on the
+type of the memory segment and the flag.
+
+If you have written a non-zero value to this proc file, anonymous shared
+memory segments are not dumped. There are three types of anonymous shared
+memory:
+
+ - IPC shared memory
+ - the memory segments created by mmap(2) with MAP_ANONYMOUS and MAP_SHARED
+ flags
+ - the memory segments created by mmap(2) with MAP_SHARED flag, and the
+ mapped file has already been unlinked
+
+Because current core dump routine doesn't distinguish these segments, you can
+only choose either dumping all anonymous shared memory segments or not.
+
+If you don't want to dump all shared memory segments attached to pid 1234,
+write 0 to the process's proc file.
+
+ $ echo 1 > /proc/1234/coredump_omit_anonymous_shared
+
+When a new process is created, the process inherits the flag status from its
+parent. It is useful to set the flag before the program runs.
+For example:
+
+ $ echo 1 > /proc/self/coredump_omit_anonymous_shared
+ $ ./some_program
+
------------------------------------------------------------------------------
Summary
------------------------------------------------------------------------------
next prev parent reply other threads:[~2007-02-16 13:42 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-02-16 13:34 [PATCH 0/4] coredump: core dump masking support v3 Kawai, Hidehiro
2007-02-16 13:39 ` [PATCH 1/4] coredump: add an interface to control the core dump routine Kawai, Hidehiro
2007-02-16 13:40 ` [PATCH 2/4] coredump: ELF: enable to omit anonymous shared memory Kawai, Hidehiro
2007-02-16 13:41 ` [PATCH 3/4] coredump: ELF-FDPIC: " Kawai, Hidehiro
2007-02-16 13:42 ` Kawai, Hidehiro [this message]
2007-02-16 15:05 ` David Howells
2007-02-16 16:50 ` Robin Holt
2007-02-16 20:09 ` David Howells
2007-03-02 16:55 ` Hugh Dickins
2007-03-03 14:10 ` David Howells
2007-03-05 19:04 ` Hugh Dickins
2007-03-06 18:13 ` David Howells
2007-03-09 14:12 ` Move to unshared VMAs in NOMMU mode? David Howells
2007-03-12 20:50 ` Robin Getz
2007-03-13 10:14 ` David Howells
2007-03-15 21:20 ` Hugh Dickins
2007-03-15 22:47 ` David Howells
2007-03-19 19:23 ` Eric W. Biederman
2007-03-20 11:06 ` David Howells
2007-03-20 16:48 ` Eric W. Biederman
2007-03-20 19:12 ` David Howells
2007-03-20 19:51 ` David Howells
2007-03-21 16:11 ` David Howells
2007-03-03 14:25 ` [PATCH] NOMMU: Hide vm_mm in NOMMU mode David Howells
2007-02-20 9:45 ` [PATCH 3/4] coredump: ELF-FDPIC: enable to omit anonymous shared memory Kawai, Hidehiro
2007-02-20 10:58 ` David Howells
2007-02-20 12:56 ` Robin Holt
2007-02-21 10:00 ` Kawai, Hidehiro
2007-02-21 11:33 ` David Howells
2007-02-21 11:54 ` Robin Holt
2007-02-22 5:33 ` Kawai, Hidehiro
2007-02-22 11:47 ` David Howells
2007-02-16 15:08 ` [PATCH 0/4] coredump: core dump masking support v3 David Howells
2007-02-20 9:48 ` Kawai, Hidehiro
2007-02-24 3:32 ` Markus Gutschke
2007-02-24 11:39 ` Pavel Machek
2007-03-01 12:35 ` Kawai, Hidehiro
2007-03-01 18:16 ` Markus Gutschke
2007-02-24 10:02 ` David Howells
2007-02-24 20:01 ` Markus Gutschke
2007-02-26 11:49 ` David Howells
2007-02-26 12:01 ` Pavel Machek
2007-02-26 12:42 ` David Howells
2007-03-02 4:41 [PATCH 0/4] coredump: core dump masking support v4 Kawai, Hidehiro
2007-03-02 4:51 ` [PATCH 4/4] coredump: documentation for proc entry Kawai, Hidehiro
2007-03-02 9:35 ` Pavel Machek
2007-03-20 11:11 ` Kawai, Hidehiro
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