From: Jianchao Wang <jianchao.w.wang@oracle.com>
To: axboe@kernel.dk
Cc: ming.lei@redhat.com, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 1/2] blk-mq: save queue mapping result into ctx directly
Date: Thu, 27 Dec 2018 10:00:40 +0800 [thread overview]
Message-ID: <1545876041-16076-2-git-send-email-jianchao.w.wang@oracle.com> (raw)
In-Reply-To: <1545876041-16076-1-git-send-email-jianchao.w.wang@oracle.com>
Currelty, the queue mapping result is saved in a two-dimensional
array. In hot path, to get a hctx, we need do following,
q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]]
This looks not efficient. Actually, we could save the queue mapping
result into ctx directly with different hctx type, like,
ctx->hctxs[type]
Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com>
---
block/blk-mq-sched.c | 2 +-
block/blk-mq-tag.c | 2 +-
block/blk-mq.c | 4 ++--
block/blk-mq.h | 5 +++--
block/blk.h | 2 +-
5 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 140933e..4090553 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -321,7 +321,7 @@ bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio)
{
struct elevator_queue *e = q->elevator;
struct blk_mq_ctx *ctx = blk_mq_get_ctx(q);
- struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, bio->bi_opf, ctx->cpu);
+ struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, bio->bi_opf, ctx);
bool ret = false;
enum hctx_type type;
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 2089c6c..a4931fc 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -170,7 +170,7 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
data->ctx = blk_mq_get_ctx(data->q);
data->hctx = blk_mq_map_queue(data->q, data->cmd_flags,
- data->ctx->cpu);
+ data->ctx);
tags = blk_mq_tags_from_data(data);
if (data->flags & BLK_MQ_REQ_RESERVED)
bt = &tags->breserved_tags;
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 3ba37b9..6898d24 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -364,7 +364,7 @@ static struct request *blk_mq_get_request(struct request_queue *q,
}
if (likely(!data->hctx))
data->hctx = blk_mq_map_queue(q, data->cmd_flags,
- data->ctx->cpu);
+ data->ctx);
if (data->cmd_flags & REQ_NOWAIT)
data->flags |= BLK_MQ_REQ_NOWAIT;
@@ -2434,7 +2434,7 @@ static void blk_mq_map_swqueue(struct request_queue *q)
continue;
hctx = blk_mq_map_queue_type(q, j, i);
-
+ ctx->hctxs[j] = hctx;
/*
* If the CPU is already set in the mask, then we've
* mapped this one already. This can happen if
diff --git a/block/blk-mq.h b/block/blk-mq.h
index d943d46..998f5cf 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -23,6 +23,7 @@ struct blk_mq_ctx {
unsigned int cpu;
unsigned short index_hw[HCTX_MAX_TYPES];
+ struct blk_mq_hw_ctx *hctxs[HCTX_MAX_TYPES];
/* incremented at dispatch time */
unsigned long rq_dispatched[2];
@@ -101,7 +102,7 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *
*/
static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
unsigned int flags,
- unsigned int cpu)
+ struct blk_mq_ctx *ctx)
{
enum hctx_type type = HCTX_TYPE_DEFAULT;
@@ -116,7 +117,7 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
q->tag_set->map[HCTX_TYPE_READ].nr_queues)
type = HCTX_TYPE_READ;
- return blk_mq_map_queue_type(q, type, cpu);
+ return ctx->hctxs[type];
}
/*
diff --git a/block/blk.h b/block/blk.h
index 848278c..5d636ee 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -38,7 +38,7 @@ 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 blk_mq_map_queue(q, REQ_OP_FLUSH, ctx->cpu)->fq;
+ return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx)->fq;
}
static inline void __blk_get_queue(struct request_queue *q)
--
2.7.4
next prev parent reply other threads:[~2018-12-27 2:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-27 2:00 [PATCH 0/2] blk-mq: small optimization for accessing of queue map Jianchao Wang
2018-12-27 2:00 ` Jianchao Wang [this message]
2018-12-27 2:00 ` [PATCH 2/2] blk-mq: save default hctx into ctx->hctxs for not-supported type Jianchao Wang
2019-01-24 10:25 [PATCH 0/2] small optimization for accessing queue map Jianchao Wang
2019-01-24 10:25 ` [PATCH 1/2] blk-mq: save queue mapping result into ctx directly Jianchao Wang
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