The patch titled
signals: microoptimize the usage of ->curr_target
has been added to the -mm tree. Its filename is
signals-microoptimize-the-usage-of-curr_target.patch
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out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: signals: microoptimize the usage of ->curr_target
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Suggested by Roland McGrath.
Initialize signal->curr_target in copy_signal(). This way ->curr_target is
never == NULL, we can kill the check in __group_complete_signal's hot path.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/fork.c | 2 +-
kernel/signal.c | 4 ----
2 files changed, 1 insertion(+), 5 deletions(-)
diff -puN kernel/fork.c~signals-microoptimize-the-usage-of-curr_target kernel/fork.c
--- a/kernel/fork.c~signals-microoptimize-the-usage-of-curr_target
+++ a/kernel/fork.c
@@ -902,7 +902,7 @@ static int copy_signal(unsigned long clo
sig->group_exit_code = 0;
sig->group_exit_task = NULL;
sig->group_stop_count = 0;
- sig->curr_target = NULL;
+ sig->curr_target = tsk;
init_sigpending(&sig->shared_pending);
INIT_LIST_HEAD(&sig->posix_timers);
diff -puN kernel/signal.c~signals-microoptimize-the-usage-of-curr_target kernel/signal.c
--- a/kernel/signal.c~signals-microoptimize-the-usage-of-curr_target
+++ a/kernel/signal.c
@@ -863,10 +863,6 @@ __group_complete_signal(int sig, struct
* Otherwise try to find a suitable thread.
*/
t = signal->curr_target;
- if (t == NULL)
- /* restart balancing at this thread */
- t = signal->curr_target = p;
-
while (!wants_signal(sig, t)) {
t = next_thread(t);
if (t == signal->curr_target)
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
git-hrt.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
signals-consolidate-checks-for-whether-or-not-to-ignore-a-signal.patch
signals-clean-dequeue_signal-from-excess-checks-and-assignments.patch
signals-consolidate-send_sigqueue-and-send_group_sigqueue.patch
signals-cleanup-security_task_kill-usage-implementation.patch
signals-re-assign-cld_continued-notification-from-the-sender-to-reciever.patch
kill_pid_info-dont-take-now-unneeded-tasklist_lock.patch
handle_stop_signal-unify-partial-full-stop-handling.patch
handle_stop_signal-use-the-cached-p-signal-value.patch
get_signal_to_deliver-use-the-cached-signal-sighand-values.patch
signals-send_sigqueue-dont-take-rcu-lock.patch
signals-send_sigqueue-dont-forget-about-handle_stop_signal.patch
signals-__group_complete_signal-cache-the-value-of-p-signal.patch
signals-send_group_sigqueue-dont-take-tasklist_lock.patch
signals-move-handle_stop_signal-into-send_signal.patch
signals-do_tkill-dont-use-tasklist_lock.patch
signals-do_tkill-dont-use-tasklist_lock-comment.patch
signals-send_sig_info-dont-take-tasklist_lock.patch
signals-microoptimize-the-usage-of-curr_target.patch
ptrace-introduce-task_detached-helper.patch
reparent_thread-use-same_thread_group.patch
document-de_thread-with-exit_notify-connection.patch
ptrace-introduce-ptrace_reparented-helper.patch
ptrace-__ptrace_unlink-use-the-ptrace_reparented-helper.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
redo-locking-of-tty-pgrp.patch
resume-tty-on-susp-and-fix-crnl-order-in-n_tty-line-discipline.patch
tty_io-fix-remaining-pid-struct-locking.patch
tty_io-fix-remaining-pid-struct-locking-small-cleanup.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
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