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author | Oleg Nesterov <oleg@redhat.com> | 2012-03-23 22:02:50 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-23 23:58:42 (GMT) |
commit | 1cc684ab75123efe7ff446eb821d44375ba8fa30 (patch) | |
tree | 165069093fc048b979ed38e537b19febdc7889d3 /arch/tile/mm | |
parent | 3e63a93b987685f02421e18b2aa452d20553a88b (diff) | |
download | linux-1cc684ab75123efe7ff446eb821d44375ba8fa30.tar.xz |
kmod: make __request_module() killable
As Tetsuo Handa pointed out, request_module() can stress the system
while the oom-killed caller sleeps in TASK_UNINTERRUPTIBLE.
The task T uses "almost all" memory, then it does something which
triggers request_module(). Say, it can simply call sys_socket(). This
in turn needs more memory and leads to OOM. oom-killer correctly
chooses T and kills it, but this can't help because it sleeps in
TASK_UNINTERRUPTIBLE and after that oom-killer becomes "disabled" by the
TIF_MEMDIE task T.
Make __request_module() killable. The only necessary change is that
call_modprobe() should kmalloc argv and module_name, they can't live in
the stack if we use UMH_KILLABLE. This memory is freed via
call_usermodehelper_freeinfo()->cleanup.
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/tile/mm')
0 files changed, 0 insertions, 0 deletions