The current logic for blocking tag allocation is rather confusing, as we first allocated and then free again a tag in blk_mq_wait_for_tags, just to attempt a non-blocking allocation and then repeat if someone else managed to grab the tag before us.
Instead change blk_mq_alloc_request_pinned to simply do a blocking tag allocation itself and use the request we get back from it. Signed-off-by: Christoph Hellwig <[email protected]> --- block/blk-mq-tag.c | 8 -------- block/blk-mq-tag.h | 1 - block/blk-mq.c | 13 ++++++------- 3 files changed, 6 insertions(+), 16 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 05e2baf..0d0640d 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -7,14 +7,6 @@ #include "blk-mq.h" #include "blk-mq-tag.h" -void blk_mq_wait_for_tags(struct blk_mq_hw_ctx *hctx, bool reserved) -{ - int tag, zero = 0; - - tag = blk_mq_get_tag(hctx, &zero, __GFP_WAIT, reserved); - blk_mq_put_tag(hctx, tag, &zero); -} - static bool bt_has_free_tags(struct blk_mq_bitmap_tags *bt) { int i; diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index 2e5e687..c959de5 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -49,7 +49,6 @@ extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int r extern void blk_mq_free_tags(struct blk_mq_tags *tags); extern unsigned int blk_mq_get_tag(struct blk_mq_hw_ctx *hctx, unsigned int *last_tag, gfp_t gfp, bool reserved); -extern void blk_mq_wait_for_tags(struct blk_mq_hw_ctx *hctx, bool reserved); extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag, unsigned int *last_tag); extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags); extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page); diff --git a/block/blk-mq.c b/block/blk-mq.c index 848b3b6..44ee79c 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -264,31 +264,30 @@ __blk_mq_alloc_request(struct request_queue *q, struct blk_mq_hw_ctx *hctx, return NULL; } - static struct request *blk_mq_alloc_request_pinned(struct request_queue *q, int rw, gfp_t gfp, bool reserved) { + bool gfp_mask = gfp & ~__GFP_WAIT; struct request *rq; do { struct blk_mq_ctx *ctx = blk_mq_get_ctx(q); struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q, ctx->cpu); - rq = __blk_mq_alloc_request(q, hctx, ctx, rw, gfp & ~__GFP_WAIT, + rq = __blk_mq_alloc_request(q, hctx, ctx, rw, gfp_mask, reserved); if (rq) break; - if (gfp & __GFP_WAIT) { - __blk_mq_run_hw_queue(hctx); - blk_mq_put_ctx(ctx); - } else { + if (!(gfp & __GFP_WAIT)) { blk_mq_put_ctx(ctx); break; } - blk_mq_wait_for_tags(hctx, reserved); + __blk_mq_run_hw_queue(hctx); + blk_mq_put_ctx(ctx); + gfp_mask = gfp; } while (1); return rq; -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
