Re: [PATCH] vhost: fix unnecessary dirty page logging

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 7/7/22 11:51, Xia, Chenbo wrote:
>> -----Original Message-----
>> From: Ding, Xuan <xuan.ding@intel.com>
>> Sent: Thursday, July 7, 2022 2:55 PM
>> To: maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
>> Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; He, Xingguang
>> <xingguang.he@intel.com>; Yang, YvonneX <yvonnex.yang@intel.com>; Jiang,
>> Cheng1 <cheng1.jiang@intel.com>; Ding, Xuan <xuan.ding@intel.com>
>> Subject: [PATCH] vhost: fix unnecessary dirty page logging
>>
>> From: Xuan Ding <xuan.ding@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.ding@intel.com>
>> ---
> 
> Reviewed-by: Chenbo Xia <chenbo.xia@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@BYAPR11MB2711.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.

> Thanks,
> Chenbo
> 

Thanks,
Maxime