[PATCH] oom: Make coredump interruptible
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From: KOSAKI Motohiro on 2 Jun 2010 10:00 > Otoh, if we make do_coredump() interruptible (and we should do this > in any case), then perhaps the TIF_MEMDIE+PF_COREDUMP is not really > needed? Afaics we always send SIGKILL along with TIF_MEMDIE. How is to make per-process oom flag + interruptible coredump? this per-process oom flag can be used vmscan shortcut exiting too. (IOW, It can help DavidR mmap_sem issue) =========================================================== Subject: [PATCH] oom: Make coredump interruptible If oom victim process is under core dumping, sending SIGKILL cause no-op. Unfortunately, coredump need relatively much memory. It mean OOM vs coredump can makes deadlock. Then, coredump logic should check the task has received SIGKILL from OOM. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro(a)jp.fujitsu.com> --- fs/binfmt_elf.c | 5 +++++ include/linux/sched.h | 3 +++ mm/oom_kill.c | 1 + 3 files changed, 9 insertions(+), 0 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 535e763..aa47979 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -2038,6 +2038,11 @@ static int elf_core_dump(struct coredump_params *cprm) page_cache_release(page); } else stop = !dump_seek(cprm->file, PAGE_SIZE); + + /* Now, The process received OOM. Exit soon! */ + if (current->signal->oom_victim) + stop = 1; + if (stop) goto end_coredump; } diff --git a/include/linux/sched.h b/include/linux/sched.h index 8485aa2..1c4fa86 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -544,6 +544,9 @@ struct signal_struct { int notify_count; struct task_struct *group_exit_task; + /* true mean the process is OOM-killer victim. */ + bool oom_victim; + /* thread group stop support, overloads group_exit_code too */ int group_stop_count; unsigned int flags; /* see SIGNAL_* flags below */ diff --git a/mm/oom_kill.c b/mm/oom_kill.c index f33a1b8..39e31bf 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -400,6 +400,7 @@ static int __oom_kill_process(struct task_struct *p, struct mem_cgroup *mem, */ p->rt.time_slice = HZ; set_tsk_thread_flag(p, TIF_MEMDIE); + p->signal->oom_victim = true; force_sig(SIGKILL, p); -- 1.6.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |