From 1fbf6fce9045b53de783c125ac22ad27d80bdb98 Mon Sep 17 00:00:00 2001 From: "Kawai, Hidehiro" Date: Thu, 19 Jul 2007 01:48:31 -0700 Subject: [PATCH] --- yaml --- r: 61603 b: refs/heads/master c: bb90110dcb9e93bf79e3c988abc6cbcabd46d57f h: refs/heads/master i: 61601: 77226d7680c0fb3081221f9e672bf763095455b5 61599: 609983e1a99db716fbc2d4d6e5ab4f3f36665ab2 v: v3 --- [refs] | 2 +- trunk/Documentation/filesystems/proc.txt | 38 ++++++++++++++++++++++++ 2 files changed, 39 insertions(+), 1 deletion(-) diff --git a/[refs] b/[refs] index a49ac3fb66ca..e69c5f04e3fd 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: ee78b0a61f0514ffc3d59257fbe6863b43477829 +refs/heads/master: bb90110dcb9e93bf79e3c988abc6cbcabd46d57f diff --git a/trunk/Documentation/filesystems/proc.txt b/trunk/Documentation/filesystems/proc.txt index 72e247ef6fa2..4a37e25e694c 100644 --- a/trunk/Documentation/filesystems/proc.txt +++ b/trunk/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 @@ -2184,4 +2185,41 @@ those 64-bit counters, process A could see an intermediate result. 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 + ------------------------------------------------------------------------------