2018-12-18 17:28:26

by Jaegeuk Kim

Subject: [PATCH] dm: give req_size precisely given by user

This patch makes dm be aware of io_pages to assign sane req_size for reads.

Cc: [email protected]
Cc: Jens Axboe <[email protected]>
Cc: Alasdair Kergon <[email protected]>
Cc: Mike Snitzer <[email protected]>
Cc: [email protected]
Fixes: 9491ae4a ("mm: don't cap request size based on read-ahead setting")
Signed-off-by: Jaegeuk Kim <[email protected]>
---
drivers/md/dm-table.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 9038c302d5c2..886790428241 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1927,6 +1927,9 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
*/
if (blk_queue_is_zoned(q))
blk_revalidate_disk_zones(t->md->disk);
+
+ /* io_pages is used for readahead */
+ q->backing_dev_info->io_pages = limits->max_sectors >> (PAGE_SHIFT - 9);
}

unsigned int dm_table_get_num_targets(struct dm_table *t)
--
2.19.0.605.g01d371f741-goog

2018-12-18 19:40:43

by Jens Axboe

Subject: Re: [PATCH] dm: give req_size precisely given by user

On 12/18/18 10:25 AM, Jaegeuk Kim wrote:
> This patch makes dm be aware of io_pages to assign sane req_size for reads.

Reviewed-by: Jens Axboe <[email protected]>

--
Jens Axboe

2018-12-18 20:47:38

by Mike Snitzer

Subject: Re: dm: give req_size precisely given by user

On Tue, Dec 18 2018 at 12:45pm -0500,
Jens Axboe <[email protected]> wrote:

> On 12/18/18 10:25 AM, Jaegeuk Kim wrote:
> > This patch makes dm be aware of io_pages to assign sane req_size for reads.
>
> Reviewed-by: Jens Axboe <[email protected]>
>

I've applied this, see:
https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-4.21&id=c6d6e9b0f6b4201c77f2cea3964dd122697e3543

2018-12-18 22:07:53

by Jaegeuk Kim

Subject: Re: dm: give req_size precisely given by user

On 12/18, Mike Snitzer wrote:
> On Tue, Dec 18 2018 at 12:45pm -0500,
> Jens Axboe <[email protected]> wrote:
>
> > On 12/18/18 10:25 AM, Jaegeuk Kim wrote:
> > > This patch makes dm be aware of io_pages to assign sane req_size for reads.
> >
> > Reviewed-by: Jens Axboe <[email protected]>
> >
>
> I've applied this, see:
> https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-4.21&id=c6d6e9b0f6b4201c77f2cea3964dd122697e3543

Got it. Thank you so much.