From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 98D4FA0540; Fri, 8 Jul 2022 09:58:08 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 7E18C40A7B; Fri, 8 Jul 2022 09:58:08 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mails.dpdk.org (Postfix) with ESMTP id 9667F406B4 for ; Fri, 8 Jul 2022 09:58:07 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1657267087; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yNaePHqMFBlK9lD5QofdHnYvnOoC5a4+wAGrEW+wQfY=; b=OrQv/mHtC3MCphOPlRAADg61xdQJbeP22++JTddlACCqnbTAJy9equMqG+GyOEVAHnJlBo 7CguVlNEJGKLc3E5+0e17U+1g8jfc0ODh0O6nPeqDr4YS033NOXv/3yNVfqWQ7Se69WO4U pnfhyxjWn794lTXT9TwxtVsPHf7G+Jg= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-622-rEoO4TItNEyCiHqv09Gnmw-1; Fri, 08 Jul 2022 03:57:59 -0400 X-MC-Unique: rEoO4TItNEyCiHqv09Gnmw-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1E037805AF5; Fri, 8 Jul 2022 07:57:59 +0000 (UTC) Received: from [10.39.208.8] (unknown [10.39.208.8]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E963A40315C; Fri, 8 Jul 2022 07:57:57 +0000 (UTC) Message-ID: <070ac224-e3f1-9bb4-d526-b1c5096b1924@redhat.com> Date: Fri, 8 Jul 2022 09:57:56 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 To: "Ding, Xuan" , "Xia, Chenbo" Cc: "dev@dpdk.org" , "Hu, Jiayu" , "He, Xingguang" , "Yang, YvonneX" , "Jiang, Cheng1" References: <20220707065513.66458-1-xuan.ding@intel.com> <5f6441be-4ab3-7a0d-483d-432a8a519919@redhat.com> From: Maxime Coquelin Subject: Re: [PATCH] vhost: fix unnecessary dirty page logging In-Reply-To: X-Scanned-By: MIMEDefang 2.85 on 10.11.54.10 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=maxime.coquelin@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Hi, On 7/8/22 09:04, Ding, Xuan wrote: > Hi, > >> -----Original Message----- >> From: Maxime Coquelin >> Sent: 2022年7月7日 19:31 >> To: Xia, Chenbo ; Ding, Xuan >> Cc: dev@dpdk.org; Hu, Jiayu ; He, Xingguang >> ; Yang, YvonneX ; Jiang, >> Cheng1 >> Subject: Re: [PATCH] vhost: fix unnecessary dirty page logging >> >> >> >> On 7/7/22 11:51, Xia, Chenbo wrote: >>>> -----Original Message----- >>>> From: Ding, Xuan >>>> Sent: Thursday, July 7, 2022 2:55 PM >>>> To: maxime.coquelin@redhat.com; Xia, Chenbo >>>> Cc: dev@dpdk.org; Hu, Jiayu ; He, Xingguang >>>> ; Yang, YvonneX ; >>>> Jiang, >>>> Cheng1 ; Ding, Xuan >>>> Subject: [PATCH] vhost: fix unnecessary dirty page logging >>>> >>>> From: Xuan Ding >>>> >>>> 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 >>>> --- >>> >>> Reviewed-by: Chenbo Xia >>> >>> 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 >