From: Jens Axboe Date: Thu, 20 Dec 2018 15:49:00 +0000 (-0700) Subject: sbitmap: add helpers for add/del wait queue handling X-Git-Tag: v5.4-rc1~1944^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9f6b7ef6c3ebe35be77b0ae3cf12e4d25ae80420;p=platform%2Fkernel%2Flinux-rpi.git sbitmap: add helpers for add/del wait queue handling After commit 5d2ee7122c73, users of sbitmap that need wait queue handling must use the provided helpers. But we only added prepare_to_wait()/finish_wait() style helpers, add the equivalent add_wait_queue/list_del wrappers as we.. This is needed to ensure kyber plays by the sbitmap waitqueue rules. Tested-by: Ming Lei Reviewed-by: Omar Sandoval Signed-off-by: Jens Axboe --- diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h index 03f50fc..14d5581 100644 --- a/include/linux/sbitmap.h +++ b/include/linux/sbitmap.h @@ -560,13 +560,13 @@ void sbitmap_queue_wake_up(struct sbitmap_queue *sbq); void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m); struct sbq_wait { - int accounted; + struct sbitmap_queue *sbq; /* if set, sbq_wait is accounted */ struct wait_queue_entry wait; }; #define DEFINE_SBQ_WAIT(name) \ struct sbq_wait name = { \ - .accounted = 0, \ + .sbq = NULL, \ .wait = { \ .private = current, \ .func = autoremove_wake_function, \ @@ -588,4 +588,16 @@ void sbitmap_prepare_to_wait(struct sbitmap_queue *sbq, void sbitmap_finish_wait(struct sbitmap_queue *sbq, struct sbq_wait_state *ws, struct sbq_wait *sbq_wait); +/* + * Wrapper around add_wait_queue(), which maintains some extra internal state + */ +void sbitmap_add_wait_queue(struct sbitmap_queue *sbq, + struct sbq_wait_state *ws, + struct sbq_wait *sbq_wait); + +/* + * Must be paired with sbitmap_add_wait_queue() + */ +void sbitmap_del_wait_queue(struct sbq_wait *sbq_wait); + #endif /* __LINUX_SCALE_BITMAP_H */ diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 5b3e56d..65c2d06 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -671,13 +671,35 @@ void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m) } EXPORT_SYMBOL_GPL(sbitmap_queue_show); +void sbitmap_add_wait_queue(struct sbitmap_queue *sbq, + struct sbq_wait_state *ws, + struct sbq_wait *sbq_wait) +{ + if (!sbq_wait->sbq) { + sbq_wait->sbq = sbq; + atomic_inc(&sbq->ws_active); + } + add_wait_queue(&ws->wait, &sbq_wait->wait); +} +EXPORT_SYMBOL_GPL(sbitmap_add_wait_queue); + +void sbitmap_del_wait_queue(struct sbq_wait *sbq_wait) +{ + list_del_init(&sbq_wait->wait.entry); + if (sbq_wait->sbq) { + atomic_dec(&sbq_wait->sbq->ws_active); + sbq_wait->sbq = NULL; + } +} +EXPORT_SYMBOL_GPL(sbitmap_del_wait_queue); + void sbitmap_prepare_to_wait(struct sbitmap_queue *sbq, struct sbq_wait_state *ws, struct sbq_wait *sbq_wait, int state) { - if (!sbq_wait->accounted) { + if (!sbq_wait->sbq) { atomic_inc(&sbq->ws_active); - sbq_wait->accounted = 1; + sbq_wait->sbq = sbq; } prepare_to_wait_exclusive(&ws->wait, &sbq_wait->wait, state); } @@ -687,9 +709,9 @@ void sbitmap_finish_wait(struct sbitmap_queue *sbq, struct sbq_wait_state *ws, struct sbq_wait *sbq_wait) { finish_wait(&ws->wait, &sbq_wait->wait); - if (sbq_wait->accounted) { + if (sbq_wait->sbq) { atomic_dec(&sbq->ws_active); - sbq_wait->accounted = 0; + sbq_wait->sbq = NULL; } } EXPORT_SYMBOL_GPL(sbitmap_finish_wait);