Hi,
On 7/8/22 09:04, Ding, Xuan wrote:
Hi,
-----Original Message-----
From: Maxime Coquelin <maxime.coque...@redhat.com>
Sent: 2022年7月7日 19:31
To: Xia, Chenbo <chenbo....@intel.com>; Ding, Xuan <xuan.d...@intel.com>
Cc: dev@dpdk.org; Hu, Jiayu <jiayu...@intel.com>; He, Xingguang
<xingguang...@intel.com>; Yang, YvonneX <yvonnex.y...@intel.com>; Jiang,
Cheng1 <cheng1.ji...@intel.com>
Subject: Re: [PATCH] vhost: fix unnecessary dirty page logging
On 7/7/22 11:51, Xia, Chenbo wrote:
-----Original Message-----
From: Ding, Xuan <xuan.d...@intel.com>
Sent: Thursday, July 7, 2022 2:55 PM
To: maxime.coque...@redhat.com; Xia, Chenbo <chenbo....@intel.com>
Cc: dev@dpdk.org; Hu, Jiayu <jiayu...@intel.com>; He, Xingguang
<xingguang...@intel.com>; Yang, YvonneX <yvonnex.y...@intel.com>;
Jiang,
Cheng1 <cheng1.ji...@intel.com>; Ding, Xuan <xuan.d...@intel.com>
Subject: [PATCH] vhost: fix unnecessary dirty page logging
From: Xuan Ding <xuan.d...@intel.com>
The dirty page logging is only required in vhost enqueue direction
for live migration. This patch removes the unnecessary dirty page
logging in vhost dequeue direction. Otherwise, it will result in a
performance drop. Some if-else judgements are also optimized to improve
performance.
Fixes: 6d823bb302c7 ("vhost: prepare sync for descriptor to mbuf
refactoring")
Fixes: b6eee3e83402 ("vhost: fix sync dequeue offload")
Signed-off-by: Xuan Ding <xuan.d...@intel.com>
---
Reviewed-by: Chenbo Xia <chenbo....@intel.com>
Although it's late in release, we can consider to merge this as I see
it impacts the performance by 5%:
http://inbox.dpdk.org/dev/BYAPR11MB2711F13CDA2B0A4535A6591EFE839@B
YAPR
11MB2711.namprd11.prod.outlook.com/T/#t
Yes, I raised we need it in -rc4 at today's Release status meeting.
I'll review it today.
But also, it will be good to know the performance issue is solved by
sharing the test results.
Yes, Intel performance results would be appreciated.
This fix patch is for the issue reported at 22.07-rc3. The refactoring patch
brings a 3%~5% perf drop in vhost sync path.
With fix patch, the perf drop introduced by refactoring is solved.
Good.
However, the testing result shows there still exists ~5% packed ring perf drop
compared with 22.03.
We find the improving checksum offload patch series in 22.07 may contribute to
the packed ring perf drop.
Because we always do checksum checks in PMD.
Could you help to double check this patch series, is it as expected?
Your assistance is really appreciated.
I will look again, but if your analysis is right, there's not much we
can do. The series is filling gaps in the checksum offload support.
I will not have time to work on it for v22.07, we're too late in the
cycle. What surprises me is that only packed ring is impacted.
Regards,
Maxime
Regards,
Xuan
Thanks,
Chenbo
Thanks,
Maxime
