From f150f02cfbc7b6b980e260856555abd73235a6b0 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Wed, 14 Dec 2016 15:06:43 -0800 Subject: [PATCH] ipc/sem: use proper list api for pending_list wakeups ... saves some LoC and looks cleaner than re-implementing the calls. Link: http://lkml.kernel.org/r/1474225896-10066-6-git-send-email-dave@stgolabs.net Signed-off-by: Davidlohr Bueso Acked-by: Manfred Spraul Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- ipc/sem.c | 38 +++++++++++++------------------------- 1 file changed, 13 insertions(+), 25 deletions(-) diff --git a/ipc/sem.c b/ipc/sem.c index 084e1f55ca72..4f5af6e7d630 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -813,8 +813,7 @@ static inline int check_restart(struct sem_array *sma, struct sem_queue *q) static int wake_const_ops(struct sem_array *sma, int semnum, struct wake_q_head *wake_q) { - struct sem_queue *q; - struct list_head *walk; + struct sem_queue *q, *tmp; struct list_head *pending_list; int semop_completed = 0; @@ -823,25 +822,19 @@ static int wake_const_ops(struct sem_array *sma, int semnum, else pending_list = &sma->sem_base[semnum].pending_const; - walk = pending_list->next; - while (walk != pending_list) { - int error; + list_for_each_entry_safe(q, tmp, pending_list, list) { + int error = perform_atomic_semop(sma, q); - q = container_of(walk, struct sem_queue, list); - walk = walk->next; + if (error > 0) + continue; + /* operation completed, remove from queue & wakeup */ + unlink_queue(sma, q); - error = perform_atomic_semop(sma, q); - - if (error <= 0) { - /* operation completed, remove from queue & wakeup */ - - unlink_queue(sma, q); - - wake_up_sem_queue_prepare(q, error, wake_q); - if (error == 0) - semop_completed = 1; - } + wake_up_sem_queue_prepare(q, error, wake_q); + if (error == 0) + semop_completed = 1; } + return semop_completed; } @@ -914,8 +907,7 @@ static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops, */ static int update_queue(struct sem_array *sma, int semnum, struct wake_q_head *wake_q) { - struct sem_queue *q; - struct list_head *walk; + struct sem_queue *q, *tmp; struct list_head *pending_list; int semop_completed = 0; @@ -925,13 +917,9 @@ static int update_queue(struct sem_array *sma, int semnum, struct wake_q_head *w pending_list = &sma->sem_base[semnum].pending_alter; again: - walk = pending_list->next; - while (walk != pending_list) { + list_for_each_entry_safe(q, tmp, pending_list, list) { int error, restart; - q = container_of(walk, struct sem_queue, list); - walk = walk->next; - /* If we are scanning the single sop, per-semaphore list of * one semaphore and that semaphore is 0, then it is not * necessary to scan further: simple increments