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 1EFEFA0C45 for ; Fri, 30 Jul 2021 16:35:44 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 188E84067A; Fri, 30 Jul 2021 16:35:44 +0200 (CEST) Received: from smartserver.smartsharesystems.com (smartserver.smartsharesystems.com [77.243.40.215]) by mails.dpdk.org (Postfix) with ESMTP id 7BEC74003F; Fri, 30 Jul 2021 16:35:41 +0200 (CEST) Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Date: Fri, 30 Jul 2021 16:35:38 +0200 Message-ID: <98CBD80474FA8B44BF855DF32C47DC35C61945@smartserver.smartshare.dk> X-MimeOLE: Produced By Microsoft Exchange V6.5 In-Reply-To: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [dpdk-dev] [dpdk-stable] [PATCH v4] mbuf: fix reset on mbuf free Thread-Index: AdeFP5VrWgBMdTVLQKWzjBVKC/98fgAC8aEQ References: <20201104170007.8026-1-olivier.matz@6wind.com> <20210119083226.GA2855@platinum> <3026375.dAcfTszmW5@thomas> From: =?iso-8859-1?Q?Morten_Br=F8rup?= To: "Olivier Matz" , "Thomas Monjalon" Cc: "Ali Alnubani" , "David Marchand" , "Alexander Kozyrev" , "Slava Ovsiienko" , , "Ferruh Yigit" , , "Andrew Rybchenko" , "Ananyev, Konstantin" , , "dpdk stable" , "Ajit Khaparde" Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH v4] mbuf: fix reset on mbuf free X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: stable-bounces@dpdk.org Sender: "stable" > From: Olivier Matz [mailto:olivier.matz@6wind.com] > Sent: Friday, 30 July 2021 14.37 >=20 > Hi Thomas, >=20 > On Sat, Jul 24, 2021 at 10:47:34AM +0200, Thomas Monjalon wrote: > > What's the follow-up for this patch? >=20 > Unfortunatly, I still don't have the time to work on this topic yet. >=20 > In my initial tests, in our lab, I didn't notice any performance > regression, but Ali has seen an impact (0.5M PPS, but I don't know how > much in percent). >=20 >=20 > > 19/01/2021 15:04, Slava Ovsiienko: > > > Hi, All > > > > > > Could we postpose this patch at least to rc2? We would like to > conduct more investigations? > > > > > > With best regards, Slava > > > > > > From: Olivier Matz > > > > On Mon, Jan 18, 2021 at 05:52:32PM +0000, Ali Alnubani wrote: > > > > > Hi, > > > > > (Sorry had to resend this to some recipients due to mail = server > problems). > > > > > > > > > > Just confirming that I can still reproduce the regression with > single core and > > > > 64B frames on other servers. > > > > > > > > Many thanks for the feedback. Can you please detail what is the > amount of > > > > performance loss in percent, and confirm the test case? (I > suppose it is > > > > testpmd io forward). > > > > > > > > Unfortunatly, I won't be able to spend a lot of time on this = soon > (sorry for > > > > that). So I see at least these 2 options: > > > > > > > > - postpone the patch again, until I can find more time to = analyze > > > > and optimize > > > > - apply the patch if the performance loss is acceptable compared > to > > > > the added value of fixing a bug > > > > > > [...] >=20 > Statu quo... >=20 > Olivier >=20 The decision should be simple: Does the DPDK project support segmented packets? If yes, then apply the patch to fix the bug! If anyone seriously cares about the regression it introduces, = optimization patches are welcome later. We shouldn't wait for it. If the patch is not applied, the documentation must be updated to = mention that we are releasing DPDK with a known bug: that segmented = packets are handled incorrectly in the scenario described in this patch. Generally, there could be some performance to gain by not supporting = segmented packets at all, as a compile time option. But that is a = different discussion. -Morten