Messages in this thread Patch in this message | | | Date | Mon, 13 Nov 2017 14:00:45 -0500 (EST) | From | Mikulas Patocka <> | Subject | [PATCH] schedule: use unlikely() |
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A small patch for schedule(), so that the code goes straght in the common case.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
--- include/linux/blkdev.h | 2 +- kernel/sched/core.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
Index: linux-2.6/include/linux/blkdev.h =================================================================== --- linux-2.6.orig/include/linux/blkdev.h +++ linux-2.6/include/linux/blkdev.h @@ -1308,7 +1308,7 @@ static inline bool blk_needs_flush_plug( { struct blk_plug *plug = tsk->plug; - return plug && + return unlikely(plug != NULL) && (!list_empty(&plug->list) || !list_empty(&plug->mq_list) || !list_empty(&plug->cb_list)); Index: linux-2.6/kernel/sched/core.c =================================================================== --- linux-2.6.orig/kernel/sched/core.c +++ linux-2.6/kernel/sched/core.c @@ -3405,7 +3405,7 @@ void __noreturn do_task_dead(void) static inline void sched_submit_work(struct task_struct *tsk) { - if (!tsk->state || tsk_is_pi_blocked(tsk)) + if (!tsk->state || unlikely(tsk_is_pi_blocked(tsk))) return; /* * If we are going to sleep and we have plugged IO queued,
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