* [PATCH] loop: Only freeze block queue when needed.
@ 2020-03-10 13:06 Martijn Coenen
2020-03-10 17:47 ` Christoph Hellwig
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Martijn Coenen @ 2020-03-10 13:06 UTC (permalink / raw)
To: axboe, hch
Cc: bvanassche, linux-block, linux-kernel, kernel-team, Martijn Coenen
__loop_update_dio() can be called as a part of loop_set_fd(), when the
block queue is not yet up and running; avoid freezing the block queue in
that case, since that is an expensive operation.
Signed-off-by: Martijn Coenen <maco@android.com>
---
drivers/block/loop.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 739b372a5112..c1c844ad6b1a 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -214,7 +214,8 @@ static void __loop_update_dio(struct loop_device *lo, bool dio)
* LO_FLAGS_READ_ONLY, both are set from kernel, and losetup
* will get updated by ioctl(LOOP_GET_STATUS)
*/
- blk_mq_freeze_queue(lo->lo_queue);
+ if (lo->lo_state == Lo_bound)
+ blk_mq_freeze_queue(lo->lo_queue);
lo->use_dio = use_dio;
if (use_dio) {
blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, lo->lo_queue);
@@ -223,7 +224,8 @@ static void __loop_update_dio(struct loop_device *lo, bool dio)
blk_queue_flag_set(QUEUE_FLAG_NOMERGES, lo->lo_queue);
lo->lo_flags &= ~LO_FLAGS_DIRECT_IO;
}
- blk_mq_unfreeze_queue(lo->lo_queue);
+ if (lo->lo_state == Lo_bound)
+ blk_mq_unfreeze_queue(lo->lo_queue);
}
static int
--
2.25.1.481.gfbce0eb801-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] loop: Only freeze block queue when needed.
2020-03-10 13:06 [PATCH] loop: Only freeze block queue when needed Martijn Coenen
@ 2020-03-10 17:47 ` Christoph Hellwig
2020-03-10 20:06 ` Chaitanya Kulkarni
2020-03-10 20:11 ` Jens Axboe
2 siblings, 0 replies; 4+ messages in thread
From: Christoph Hellwig @ 2020-03-10 17:47 UTC (permalink / raw)
To: Martijn Coenen
Cc: axboe, hch, bvanassche, linux-block, linux-kernel, kernel-team
On Tue, Mar 10, 2020 at 02:06:54PM +0100, Martijn Coenen wrote:
> __loop_update_dio() can be called as a part of loop_set_fd(), when the
> block queue is not yet up and running; avoid freezing the block queue in
> that case, since that is an expensive operation.
>
> Signed-off-by: Martijn Coenen <maco@android.com>
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] loop: Only freeze block queue when needed.
2020-03-10 13:06 [PATCH] loop: Only freeze block queue when needed Martijn Coenen
2020-03-10 17:47 ` Christoph Hellwig
@ 2020-03-10 20:06 ` Chaitanya Kulkarni
2020-03-10 20:11 ` Jens Axboe
2 siblings, 0 replies; 4+ messages in thread
From: Chaitanya Kulkarni @ 2020-03-10 20:06 UTC (permalink / raw)
To: Martijn Coenen, axboe, hch
Cc: bvanassche, linux-block, linux-kernel, kernel-team
Looks good to me.
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
On 03/10/2020 06:07 AM, Martijn Coenen wrote:
> __loop_update_dio() can be called as a part of loop_set_fd(), when the
> block queue is not yet up and running; avoid freezing the block queue in
> that case, since that is an expensive operation.
>
> Signed-off-by: Martijn Coenen<maco@android.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] loop: Only freeze block queue when needed.
2020-03-10 13:06 [PATCH] loop: Only freeze block queue when needed Martijn Coenen
2020-03-10 17:47 ` Christoph Hellwig
2020-03-10 20:06 ` Chaitanya Kulkarni
@ 2020-03-10 20:11 ` Jens Axboe
2 siblings, 0 replies; 4+ messages in thread
From: Jens Axboe @ 2020-03-10 20:11 UTC (permalink / raw)
To: Martijn Coenen, hch; +Cc: bvanassche, linux-block, linux-kernel, kernel-team
On 3/10/20 7:06 AM, Martijn Coenen wrote:
> __loop_update_dio() can be called as a part of loop_set_fd(), when the
> block queue is not yet up and running; avoid freezing the block queue in
> that case, since that is an expensive operation.
Applied, thanks.
--
Jens Axboe
^ permalink raw reply [flat|nested] 4+ messages in thread
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2020-03-10 13:06 [PATCH] loop: Only freeze block queue when needed Martijn Coenen
2020-03-10 17:47 ` Christoph Hellwig
2020-03-10 20:06 ` Chaitanya Kulkarni
2020-03-10 20:11 ` Jens Axboe
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