From f70ced09170761acb69840cafaace4abc72cba4b Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Sep 2014 23:23:47 +0800 Subject: blk-mq: support per-distpatch_queue flush machinery This patch supports to run one single flush machinery for each blk-mq dispatch queue, so that: - current init_request and exit_request callbacks can cover flush request too, then the buggy copying way of initializing flush request's pdu can be fixed - flushing performance gets improved in case of multi hw-queue In fio sync write test over virtio-blk(4 hw queues, ioengine=sync, iodepth=64, numjobs=4, bs=4K), it is observed that througput gets increased a lot over my test environment: - throughput: +70% in case of virtio-blk over null_blk - throughput: +30% in case of virtio-blk over SSD image The multi virtqueue feature isn't merged to QEMU yet, and patches for the feature can be found in below tree: git://kernel.ubuntu.com/ming/qemu.git v2.1.0-mq.4 And simply passing 'num_queues=4 vectors=5' should be enough to enable multi queue(quad queue) feature for QEMU virtio-blk. Suggested-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk.h | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'block/blk.h') diff --git a/block/blk.h b/block/blk.h index 7ecdd8517e69b..43b036185712c 100644 --- a/block/blk.h +++ b/block/blk.h @@ -2,6 +2,8 @@ #define BLK_INTERNAL_H #include +#include +#include "blk-mq.h" /* Amount of time in which a process may batch requests */ #define BLK_BATCH_TIME (HZ/50UL) @@ -31,7 +33,14 @@ extern struct ida blk_queue_ida; static inline struct blk_flush_queue *blk_get_flush_queue( struct request_queue *q, struct blk_mq_ctx *ctx) { - return q->fq; + struct blk_mq_hw_ctx *hctx; + + if (!q->mq_ops) + return q->fq; + + hctx = q->mq_ops->map_queue(q, ctx->cpu); + + return hctx->fq; } static inline void __blk_get_queue(struct request_queue *q) @@ -39,8 +48,9 @@ static inline void __blk_get_queue(struct request_queue *q) kobject_get(&q->kobj); } -struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q); -void blk_free_flush_queue(struct blk_flush_queue *fq); +struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q, + int node, int cmd_size); +void blk_free_flush_queue(struct blk_flush_queue *q); int blk_init_rl(struct request_list *rl, struct request_queue *q, gfp_t gfp_mask); -- cgit v1.2.3