The patch titled k_getrusage: don't take rcu_read_lock() has been added to the -mm tree. Its filename is k_getrusage-dont-take-rcu_read_lock.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 *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: k_getrusage: don't take rcu_read_lock() From: Oleg Nesterov <oleg@xxxxxxxxxx> Just a trivial example, more to come. k_getrusage() holds rcu_read_lock() because it was previously required by lock_task_sighand(). Unneeded now. Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> Cc: Roland McGrath <roland@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/sys.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff -puN kernel/sys.c~k_getrusage-dont-take-rcu_read_lock kernel/sys.c --- a/kernel/sys.c~k_getrusage-dont-take-rcu_read_lock +++ a/kernel/sys.c @@ -1566,11 +1566,8 @@ static void k_getrusage(struct task_stru goto out; } - rcu_read_lock(); - if (!lock_task_sighand(p, &flags)) { - rcu_read_unlock(); + if (!lock_task_sighand(p, &flags)) return; - } switch (who) { case RUSAGE_BOTH: @@ -1606,9 +1603,7 @@ static void k_getrusage(struct task_stru default: BUG(); } - unlock_task_sighand(p, &flags); - rcu_read_unlock(); out: cputime_to_timeval(utime, &r->ru_utime); _ Patches currently in -mm which might be from oleg@xxxxxxxxxx are kthread-synchronization-issues.patch kthread-add-a-missing-memory-barrier-to-kthread_stop.patch kthread-call-wake_up_process-without-the-lock-being-held.patch mmap_region-cleanup-the-final-vma_merge-related-code.patch remove-unused-variable-from-send_signal.patch turn-legacy_queue-macro-into-static-inline-function.patch consolidate-checking-for-ignored-legacy-signals.patch consolidate-checking-for-ignored-legacy-signals-simplify.patch signals-do_signal_stop-use-signal_group_exit.patch signals-do_group_exit-use-signal_group_exit-more-consistently.patch lock_task_sighand-add-rcu-lock-unlock.patch k_getrusage-dont-take-rcu_read_lock.patch do_task_stat-dont-take-rcu_read_lock.patch workqueues-shrink-cpu_populated_map-when-cpu-dies.patch workqueues-shrink-cpu_populated_map-when-cpu-dies-fix.patch cleanup_workqueue_thread-remove-the-unneeded-cpu-parameter.patch simplify-cpu_hotplug_begin-put_online_cpus.patch timers-simplify-lockdep-stuff.patch hrtimers-simplify-lockdep-stuff.patch kill-double_spin_lock.patch redo-locking-of-tty-pgrp.patch procfs-task-exe-symlink.patch procfs-task-exe-symlink-fix.patch procfs-task-exe-symlink-fix-2.patch free_pidmap-turn-it-into-free_pidmapstruct-upid.patch put_pid-make-sure-we-dont-free-the-live-pid.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