From ff73ca5220d4f94e7d9eaa5ed8258629362c81cf Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 29 Jan 2015 15:10:08 +0100 Subject: [PATCH 213/365] block/mq: don't complete requests via IPI The IPI runs in hardirq context and there are sleeping locks. This patch moves the completion into a workqueue. Signed-off-by: Sebastian Andrzej Siewior --- block/blk-core.c | 3 +++ block/blk-mq.c | 20 ++++++++++++++++++++ include/linux/blk-mq.h | 2 +- include/linux/blkdev.h | 1 + 4 files changed, 25 insertions(+), 1 deletion(-) diff --git a/block/blk-core.c b/block/blk-core.c index e0f201856185..ebac0d312d3d 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -127,6 +127,9 @@ void blk_rq_init(struct request_queue *q, struct request *rq) INIT_LIST_HEAD(&rq->queuelist); INIT_LIST_HEAD(&rq->timeout_list); +#ifdef CONFIG_PREEMPT_RT_FULL + INIT_WORK(&rq->work, __blk_mq_complete_request_remote_work); +#endif rq->cpu = -1; rq->q = q; rq->__sector = (sector_t) -1; diff --git a/block/blk-mq.c b/block/blk-mq.c index aca3af98d337..d877210e9a1b 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -184,6 +184,9 @@ static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, rq->resid_len = 0; rq->sense = NULL; +#ifdef CONFIG_PREEMPT_RT_FULL + INIT_WORK(&rq->work, __blk_mq_complete_request_remote_work); +#endif INIT_LIST_HEAD(&rq->timeout_list); rq->timeout = 0; @@ -352,6 +355,17 @@ void blk_mq_end_request(struct request *rq, int error) } EXPORT_SYMBOL(blk_mq_end_request); +#ifdef CONFIG_PREEMPT_RT_FULL + +void __blk_mq_complete_request_remote_work(struct work_struct *work) +{ + struct request *rq = container_of(work, struct request, work); + + rq->q->softirq_done_fn(rq); +} + +#else + static void __blk_mq_complete_request_remote(void *data) { struct request *rq = data; @@ -359,6 +373,8 @@ static void __blk_mq_complete_request_remote(void *data) rq->q->softirq_done_fn(rq); } +#endif + static void blk_mq_ipi_complete_request(struct request *rq) { struct blk_mq_ctx *ctx = rq->mq_ctx; @@ -375,10 +391,14 @@ static void blk_mq_ipi_complete_request(struct request *rq) shared = cpus_share_cache(cpu, ctx->cpu); if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { +#ifdef CONFIG_PREEMPT_RT_FULL + schedule_work_on(ctx->cpu, &rq->work); +#else rq->csd.func = __blk_mq_complete_request_remote; rq->csd.info = rq; rq->csd.flags = 0; smp_call_function_single_async(ctx->cpu, &rq->csd); +#endif } else { rq->q->softirq_done_fn(rq); } diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 00b40432cba0..4498f82eafe6 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -209,7 +209,7 @@ static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag) return unique_tag & BLK_MQ_UNIQUE_TAG_MASK; } - +void __blk_mq_complete_request_remote_work(struct work_struct *work); int blk_mq_request_started(struct request *rq); void blk_mq_start_request(struct request *rq); void blk_mq_end_request(struct request *rq, int error); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index b5d23bc500b5..552fb3fb991b 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -89,6 +89,7 @@ struct request { struct list_head queuelist; union { struct call_single_data csd; + struct work_struct work; u64 fifo_time; }; -- 2.28.0