The commit is pushed to "branch-rh7-3.10.0-229.7.2.vz7.8.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git after rh7-3.10.0-229.7.2.vz7.8.5 ------> commit b7e9193a5cee21eeaaf2a2d39c8561e10eb39c21 Author: Maxim Patlasov <mpatla...@virtuozzo.com> Date: Mon Oct 12 14:18:49 2015 +0400
ms/cfq-iosched: remove @gfp_mask from cfq_find_alloc_queue() Backport 2da8de0bb from mainline. Original patch description: Even when allocations fail, cfq_find_alloc_queue() always returns a valid cfq_queue by falling back to the oom cfq_queue. As such, there isn't much point in taking @gfp_mask and trying "harder" if __GFP_WAIT is set. GFP_NOWAIT allocations don't fail often and even when they do the degraded behavior is acceptable and temporary. After all, the only reason get_request(), which ultimately determines the gfp_mask, cares about __GFP_WAIT is to guarantee request allocation, assuming IO forward progress, for callers which are willing to wait. There's no reason for cfq_find_alloc_queue() to behave differently on __GFP_WAIT when it already has a fallback mechanism. Remove @gfp_mask from cfq_find_alloc_queue() and propagate the changes to its callers. This simplifies the function quite a bit and will help making async queues per-cfq_group. v2: Updated to reflect GFP_ATOMIC -> GPF_NOWAIT. Signed-off-by: Tejun Heo <t...@kernel.org> Reviewed-by: Jeff Moyer <jmo...@redhat.com> Cc: Vivek Goyal <vgo...@redhat.com> Cc: Arianna Avanzini <avanzini.aria...@gmail.com> Signed-off-by: Jens Axboe <ax...@fb.com> https://jira.sw.ru/browse/PSBM-39956 Signed-off-by: Maxim Patlasov <mpatla...@virtuozzo.com> Acked-by: Dmitry Monakhov <dmonak...@virtuozzo.com> --- block/cfq-iosched.c | 46 ++++++++++------------------------------------ 1 file changed, 10 insertions(+), 36 deletions(-) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 1d7fce9..987c0f9 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -860,8 +860,7 @@ static inline int cfqg_busy_async_queues(struct cfq_data *cfqd, static void cfq_dispatch_insert(struct request_queue *, struct request *); static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, bool is_sync, - struct cfq_io_cq *cic, struct bio *bio, - gfp_t gfp_mask); + struct cfq_io_cq *cic, struct bio *bio); static inline struct cfq_io_cq *icq_to_cic(struct io_cq *icq) { @@ -3569,8 +3568,7 @@ static void check_ioprio_changed(struct cfq_io_cq *cic, struct bio *bio) cfqq = cic->cfqq[BLK_RW_ASYNC]; if (cfqq) { struct cfq_queue *new_cfqq; - new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic, bio, - GFP_ATOMIC); + new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic, bio); if (new_cfqq) { cic->cfqq[BLK_RW_ASYNC] = new_cfqq; cfq_put_queue(cfqq); @@ -3641,13 +3639,12 @@ static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { static struct cfq_queue * cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, - struct bio *bio, gfp_t gfp_mask) + struct bio *bio) { struct blkcg *blkcg; - struct cfq_queue *cfqq, *new_cfqq = NULL; + struct cfq_queue *cfqq; struct cfq_group *cfqg; -retry: rcu_read_lock(); blkcg = bio_blkcg(bio); @@ -3659,27 +3656,9 @@ retry: * originally, since it should just be a temporary situation. */ if (!cfqq || cfqq == &cfqd->oom_cfqq) { - cfqq = NULL; - if (new_cfqq) { - cfqq = new_cfqq; - new_cfqq = NULL; - } else if (gfp_mask & __GFP_WAIT) { - rcu_read_unlock(); - spin_unlock_irq(cfqd->queue->queue_lock); - new_cfqq = kmem_cache_alloc_node(cfq_pool, - gfp_mask | __GFP_ZERO, - cfqd->queue->node); - spin_lock_irq(cfqd->queue->queue_lock); - if (new_cfqq) - goto retry; - else - return &cfqd->oom_cfqq; - } else { - cfqq = kmem_cache_alloc_node(cfq_pool, - gfp_mask | __GFP_ZERO, - cfqd->queue->node); - } - + cfqq = kmem_cache_alloc_node(cfq_pool, + GFP_ATOMIC | __GFP_ZERO, + cfqd->queue->node); if (cfqq) { cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); cfq_init_prio_data(cfqq, cic); @@ -3689,9 +3668,6 @@ retry: cfqq = &cfqd->oom_cfqq; } - if (new_cfqq) - kmem_cache_free(cfq_pool, new_cfqq); - rcu_read_unlock(); return cfqq; } @@ -3716,7 +3692,7 @@ cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) static struct cfq_queue * cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, - struct bio *bio, gfp_t gfp_mask) + struct bio *bio) { const int ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio); const int ioprio = IOPRIO_PRIO_DATA(cic->ioprio); @@ -3729,7 +3705,7 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, } if (!cfqq) - cfqq = cfq_find_alloc_queue(cfqd, is_sync, cic, bio, gfp_mask); + cfqq = cfq_find_alloc_queue(cfqd, is_sync, cic, bio); /* * pin the queue now that it's allocated, scheduler exit will prune it @@ -4280,8 +4256,6 @@ cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio, const bool is_sync = rq_is_sync(rq); struct cfq_queue *cfqq; - might_sleep_if(gfp_mask & __GFP_WAIT); - spin_lock_irq(q->queue_lock); check_ioprio_changed(cic, bio); @@ -4289,7 +4263,7 @@ cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio, new_queue: cfqq = cic_to_cfqq(cic, is_sync); if (!cfqq || cfqq == &cfqd->oom_cfqq) { - cfqq = cfq_get_queue(cfqd, is_sync, cic, bio, gfp_mask); + cfqq = cfq_get_queue(cfqd, is_sync, cic, bio); cic_set_cfqq(cic, cfqq, is_sync); } else { /* _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel