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authorChristoph Hellwig <hch@lst.de>2014-05-27 20:59:48 +0200
committerJens Axboe <axboe@fb.com>2014-05-28 09:49:23 -0600
commita3bd77567cae6af700dcd245148befc73fc89a50 (patch)
tree465934c4f1fb0687da5d862e5221d54c0d34eb2f
parent5dee857720db15e2c8ef0c03f7eeac00c4c63cb2 (diff)
downloadkernel-a3bd77567cae6af700dcd245148befc73fc89a50.tar.gz
blk-mq: remove blk_mq_wait_for_tags
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 <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
-rw-r--r--block/blk-mq-tag.c8
-rw-r--r--block/blk-mq-tag.h1
-rw-r--r--block/blk-mq.c13
3 files changed, 6 insertions, 16 deletions
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 05e2baf4fa0d..0d0640d38a06 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 2e5e6872d089..c959de58d2a5 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 04ef7ecb3c7f..3224888d329a 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;