| Message ID | 1596722082-31817-1-git-send-email-xianting_tian@126.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | blkcg: add plugging support for punt bio | expand |
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?
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.
Thanks TJ and your previous guide to me. I will summarize and resubmit the patch. -----Original Message----- From: Tejun Heo [mailto:htejun@gmail.com] On Behalf Of Tejun Heo Sent: Wednesday, September 09, 2020 2:03 AM To: tianxianting (RD) <tian.xianting@h3c.com> Cc: axboe@kernel.dk; cgroups@vger.kernel.org; linux-block@vger.kernel.org; linux-kernel@vger.kernel.org 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
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); } /**
Try to merge continuous bio to current task's plug fisrt. Signed-off-by: Xianting Tian <xianting_tian@126.com> --- block/blk-cgroup.c | 3 +++ 1 file changed, 3 insertions(+)