The patch titled Subject: coredump: change wait_for_dump_helpers() to use wait_event_interruptible() has been added to the -mm tree. Its filename is coredump-change-wait_for_dump_helpers-to-use-wait_event_interruptible.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Oleg Nesterov <oleg@xxxxxxxxxx> Subject: coredump: change wait_for_dump_helpers() to use wait_event_interruptible() wait_for_dump_helpers() calls wake_up/kill_fasync from inside the wait_event-like loop. This is not needed and in fact this is not strictly correct, we can/should do this only once after we change pipe->writers. We could even check if it becomes zero. Change this code to use use wait_event_interruptible(), this can also help to make this wait freezable. With this patch we check pipe->readers without pipe_lock(), this is fine. Once we see pipe->readers == 1 we know that the handler decremented the counter, this is all we need. Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Acked-by: Mandeep Singh Baines <msb@xxxxxxxxxxxx> Cc: Neil Horman <nhorman@xxxxxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/coredump.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff -puN fs/coredump.c~coredump-change-wait_for_dump_helpers-to-use-wait_event_interruptible fs/coredump.c --- a/fs/coredump.c~coredump-change-wait_for_dump_helpers-to-use-wait_event_interruptible +++ a/fs/coredump.c @@ -439,17 +439,20 @@ static void wait_for_dump_helpers(struct pipe_lock(pipe); pipe->readers++; pipe->writers--; + wake_up_interruptible_sync(&pipe->wait); + kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); + pipe_unlock(pipe); - while ((pipe->readers > 1) && (!signal_pending(current))) { - wake_up_interruptible_sync(&pipe->wait); - kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); - pipe_wait(pipe); - } + /* + * We actually want wait_event_freezable() but then we need + * to clear TIF_SIGPENDING and improve dump_interrupted(). + */ + wait_event_interruptible(pipe->wait, pipe->readers == 1); + pipe_lock(pipe); pipe->readers--; pipe->writers++; pipe_unlock(pipe); - } /* _ Patches currently in -mm which might be from oleg@xxxxxxxxxx are thinkpad-acpi-kill-hotkey_thread_mutex.patch lockdep-introduce-lock_acquire_exclusive-shared-helper-macros.patch lglock-update-lockdep-annotations-to-report-recursive-local-locks.patch ptrace-add-ability-to-retrieve-signals-without-removing-from-a-queue-v4.patch selftest-add-a-test-case-for-ptrace_peeksiginfo.patch coredump-only-sigkill-should-interrupt-the-coredumping-task.patch coredump-ensure-that-sigkill-always-kills-the-dumping-thread.patch coredump-sanitize-the-setting-of-signal-group_exit_code.patch coredump-introduce-dump_interrupted.patch coredump-factor-out-the-setting-of-pf_dumpcore.patch coredump-change-wait_for_dump_helpers-to-use-wait_event_interruptible.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html