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* [PATCH] block: fix comments about choosing request list
@ 2018-10-16  8:53 Konstantin Khlebnikov
  2018-10-16 14:45 ` Jens Axboe
  0 siblings, 1 reply; 3+ messages in thread
From: Konstantin Khlebnikov @ 2018-10-16  8:53 UTC (permalink / raw)
  To: Jens Axboe, linux-kernel

Request list is determined by blk_get_rl() and without queue_lock.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
---
 include/linux/blk-cgroup.h |    8 ++++----
 include/linux/blkdev.h     |    9 +++++----
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 6d766a19f2bb..dbff5a25f810 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -520,10 +520,10 @@ static inline void blkg_put(struct blkcg_gq *blkg)
  * @q: request_queue of interest
  * @bio: bio which will be attached to the allocated request (may be %NULL)
  *
- * The caller wants to allocate a request from @q to use for @bio.  Find
- * the request_list to use and obtain a reference on it.  Should be called
- * under queue_lock.  This function is guaranteed to return non-%NULL
- * request_list.
+ * The caller wants to allocate a request from @q to use for @bio.
+ * Find the request_list to use and obtain a reference on it.
+ *
+ * This function is guaranteed to return non-%NULL request_list.
  */
 static inline struct request_list *blk_get_rl(struct request_queue *q,
 					      struct bio *bio)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6980014357d4..b5fec0bc72f2 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -444,10 +444,11 @@ struct request_queue {
 	struct rq_qos		*rq_qos;
 
 	/*
-	 * If blkcg is not used, @q->root_rl serves all requests.  If blkcg
-	 * is used, root blkg allocates from @q->root_rl and all other
-	 * blkgs from their own blkg->rl.  Which one to use should be
-	 * determined using bio_request_list().
+	 * If blkcg is not used, @q->root_rl serves all requests.
+	 * If blkcg is used, root blkg allocates from @q->root_rl and
+	 * all other blkgs from their own blkg->rl.
+	 *
+	 * Which one to use should be determined using blk_get_rl().
 	 */
 	struct request_list	root_rl;
 


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] block: fix comments about choosing request list
  2018-10-16  8:53 [PATCH] block: fix comments about choosing request list Konstantin Khlebnikov
@ 2018-10-16 14:45 ` Jens Axboe
  2018-10-16 14:59   ` Konstantin Khlebnikov
  0 siblings, 1 reply; 3+ messages in thread
From: Jens Axboe @ 2018-10-16 14:45 UTC (permalink / raw)
  To: Konstantin Khlebnikov, linux-kernel

On 10/16/18 2:53 AM, Konstantin Khlebnikov wrote:
> Request list is determined by blk_get_rl() and without queue_lock.

This code is going away shortly, so let's just leave the comment
alone.

-- 
Jens Axboe


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] block: fix comments about choosing request list
  2018-10-16 14:45 ` Jens Axboe
@ 2018-10-16 14:59   ` Konstantin Khlebnikov
  0 siblings, 0 replies; 3+ messages in thread
From: Konstantin Khlebnikov @ 2018-10-16 14:59 UTC (permalink / raw)
  To: Jens Axboe, linux-kernel

On 16.10.2018 17:45, Jens Axboe wrote:
> On 10/16/18 2:53 AM, Konstantin Khlebnikov wrote:
>> Request list is determined by blk_get_rl() and without queue_lock.
> 
> This code is going away shortly, so let's just leave the comment
> alone.
> 

Ok, I see some patches in flight for 420

Probably they also fixes linking non-bio based request with cgroups?
I've found that old stack calls blk_rq_set_rl() for all request
while MQ do this only in blk_mq_bio_to_request,
in blk_mq_get_request() request gets only io-context.

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2018-10-16 14:59 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2018-10-16  8:53 [PATCH] block: fix comments about choosing request list Konstantin Khlebnikov
2018-10-16 14:45 ` Jens Axboe
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