The patch titled Subject: coredump: make wait_for_dump_helpers() freezable has been added to the -mm tree. Its filename is coredump-make-wait_for_dump_helpers-freezable.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: make wait_for_dump_helpers() freezable 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. With this change it is trivial to convert this code to use wait_event_freezable() and make this function freezable/killable, only SIGKILL can set TIF_SIGPENDING. 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. Note: wait_event_freezable() is "strange", perhaps it should be changed or simply removed. In the latter case we can change this code again to use freezer_do_not_count + wait_event_interruptible. Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Mandeep Singh Baines <msb@xxxxxxxxxxxx> Cc: Neil Horman <nhorman@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>a Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/coredump.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff -puN fs/coredump.c~coredump-make-wait_for_dump_helpers-freezable fs/coredump.c --- a/fs/coredump.c~coredump-make-wait_for_dump_helpers-freezable +++ a/fs/coredump.c @@ -32,6 +32,7 @@ #include <linux/pipe_fs_i.h> #include <linux/oom.h> #include <linux/compat.h> +#include <linux/freezer.h> #include <asm/uaccess.h> #include <asm/mmu_context.h> @@ -428,17 +429,16 @@ 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); - } + wait_event_freezable(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 origin.patch usermodehelper-cleanup-fix-__orderly_poweroff-argv_free.patch signal-allow-to-send-any-siginfo-to-itself.patch kernel-signalc-fix-suboptimal-printk-usage.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-factor-out-the-setting-of-pf_dumpcore.patch freezer-do-not-send-a-fake-signal-to-a-pf_dumpcore-thread.patch coredump-make-wait_for_dump_helpers-freezable.patch lockdep-check-that-no-locks-held-at-freeze-time.patch lockdep-check-that-no-locks-held-at-freeze-time-v2.patch lockdep-check-that-no-locks-held-at-freeze-time-fix.patch coredump-use-a-freezable_schedule-for-the-coredump_finish-wait.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