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authorJens Axboe <axboe@kernel.dk>2018-05-30 15:26:07 +0800
committerJens Axboe <axboe@kernel.dk>2018-05-30 10:43:58 -0600
commit9c5587346490ad4355e8de6ae402b76e55c411d5 (patch)
treec3d4ef3bb13f175030152a1721ad1d33c0aa7389 /block
parent5de815a7eedfacf593817ef34634eaa9b75a1482 (diff)
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blk-mq: abstract out blk-mq-sched rq list iteration bio merge helper
No functional changes in this patch, just a prep patch for utilizing this in an IO scheduler. Signed-off-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Omar Sandoval <osandov@fb.com>
Diffstat (limited to 'block')
-rw-r--r--block/blk-mq-sched.c34
1 files changed, 24 insertions, 10 deletions
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 25c14c58385c..b0f2c2a40a0c 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -268,19 +268,16 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,
EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge);
/*
- * Reverse check our software queue for entries that we could potentially
- * merge with. Currently includes a hand-wavy stop count of 8, to not spend
- * too much time checking for merges.
+ * Iterate list of requests and see if we can merge this bio with any
+ * of them.
*/
-static bool blk_mq_attempt_merge(struct request_queue *q,
- struct blk_mq_ctx *ctx, struct bio *bio)
+bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list,
+ struct bio *bio)
{
struct request *rq;
int checked = 8;
- lockdep_assert_held(&ctx->lock);
-
- list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) {
+ list_for_each_entry_reverse(rq, list, queuelist) {
bool merged = false;
if (!checked--)
@@ -305,13 +302,30 @@ static bool blk_mq_attempt_merge(struct request_queue *q,
continue;
}
- if (merged)
- ctx->rq_merged++;
return merged;
}
return false;
}
+EXPORT_SYMBOL_GPL(blk_mq_bio_list_merge);
+
+/*
+ * Reverse check our software queue for entries that we could potentially
+ * merge with. Currently includes a hand-wavy stop count of 8, to not spend
+ * too much time checking for merges.
+ */
+static bool blk_mq_attempt_merge(struct request_queue *q,
+ struct blk_mq_ctx *ctx, struct bio *bio)
+{
+ lockdep_assert_held(&ctx->lock);
+
+ if (blk_mq_bio_list_merge(q, &ctx->rq_list, bio)) {
+ ctx->rq_merged++;
+ return true;
+ }
+
+ return false;
+}
bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio)
{