Try to merge continuous bio to current task's plug fisrt.
Signed-off-by: Xianting Tian <[email protected]>
---
block/blk-cgroup.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 0ecc897..fe5d361 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -122,6 +122,7 @@ static void blkg_async_bio_workfn(struct work_struct *work)
async_bio_work);
struct bio_list bios = BIO_EMPTY_LIST;
struct bio *bio;
+ struct blk_plug plug;
/* as long as there are pending bios, @blkg can't go away */
spin_lock_bh(&blkg->async_bio_lock);
@@ -129,8 +130,10 @@ static void blkg_async_bio_workfn(struct work_struct *work)
bio_list_init(&blkg->async_bios);
spin_unlock_bh(&blkg->async_bio_lock);
+ blk_start_plug(&plug);
while ((bio = bio_list_pop(&bios)))
submit_bio(bio);
+ blk_finish_plug(&plug);
}
/**
--
1.8.3.1
On 8/6/20 7:54 AM, Xianting Tian wrote:
> Try to merge continuous bio to current task's plug fisrt.
The patch looks fine to me, but I'd really like to see a bit more
changelog here. The commit message should explain why the change
is made, rather it's a very brief explanation of what it does.
If the bio list is contiguous, then we do the plugging to improve
merging at the lower level. You probably ran into a case where
you saw sub-optimal merging? And now the performance is better
with the patch? How much?
--
Jens Axboe
On Sat, Sep 05, 2020 at 11:25:03AM +0000, Tianxianting wrote:
> Hi jens,tj
> Could you share a couple of minutes to comment it?
> I really appreciate it
The result looks fine to me but can you please summarize that in the commit
message of the patch?
Thanks.
--
tejun
Thanks TJ and your previous guide to me.
I will summarize and resubmit the patch.
-----Original Message-----
From: Tejun Heo [mailto:[email protected]] On Behalf Of Tejun Heo
Sent: Wednesday, September 09, 2020 2:03 AM
To: tianxianting (RD) <[email protected]>
Cc: [email protected]; [email protected]; [email protected]; [email protected]
Subject: Re: [PATCH] blkcg: add plugging support for punt bio
On Sat, Sep 05, 2020 at 11:25:03AM +0000, Tianxianting wrote:
> Hi jens,tj
> Could you share a couple of minutes to comment it?
> I really appreciate it
The result looks fine to me but can you please summarize that in the commit message of the patch?
Thanks.
--
tejun