This patch adds the documentation for /proc/<pid>/coredump_omit_anonymous_shared.
Signed-off-by: Hidehiro Kawai <[EMAIL PROTECTED]> --- Documentation/filesystems/proc.txt | 38 +++++++++++++++++++++++++++ 1 files changed, 38 insertions(+) Index: linux-2.6.20-mm2/Documentation/filesystems/proc.txt =================================================================== --- linux-2.6.20-mm2.orig/Documentation/filesystems/proc.txt +++ linux-2.6.20-mm2/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 ------------------------------------------------------------------------------ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
