From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5CBBBEB64DA for ; Fri, 30 Jun 2023 23:38:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229774AbjF3XiJ (ORCPT ); Fri, 30 Jun 2023 19:38:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229447AbjF3XiI (ORCPT ); Fri, 30 Jun 2023 19:38:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C47461FC3; Fri, 30 Jun 2023 16:38:07 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5A4D26179C; Fri, 30 Jun 2023 23:38:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23459C433C8; Fri, 30 Jun 2023 23:38:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1688168286; bh=aDoGh6BHxlBh8t8fWNrlX4oW9QEZMOk3iSMADxRRBXo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=gjxEOHFtQDjhnWQdK9QdGAprDJKS6adNgQsHCKsmOTrUk0tHMJ0hkwvzDLfzNtYp8 icQEI1wly+b79kcGi5TeSAte360WuGtIWKvvG1p8K8UFr6elCYdKgiAttgVntvJGmw I/mf+Ob2ls5a1zagzuBdqNtx3rGOoiyX2vu7bpawkLhJ2rFDhLfBEsH/ex4SBSRy6x waEhg1HGyj/3ZRdvfVQgU54X19N7XHmK/IXWc4Lg3gF/LyRJnSqk92av9VeAZ7GrsG SWosTlvCtf3qucEgi0NbdTaMuke2O3MRoCLbt2dZBc5+dAxd2aess/d8te8pvKpjx+ ioP351LYUGItA== Date: Fri, 30 Jun 2023 16:38:05 -0700 From: Jakub Kicinski To: Long Li Cc: Greg KH , Paolo Abeni , "longli@linuxonhyperv.com" , Jason Gunthorpe , Leon Romanovsky , Ajay Sharma , Dexuan Cui , KY Srinivasan , Haiyang Zhang , Wei Liu , "David S. Miller" , Eric Dumazet , "linux-rdma@vger.kernel.org" , "linux-hyperv@vger.kernel.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: Re: [Patch v3] net: mana: Batch ringing RX queue doorbell on receiving packets Message-ID: <20230630163805.79c0bdf5@kernel.org> In-Reply-To: References: <1687823827-15850-1-git-send-email-longli@linuxonhyperv.com> <36c95dd6babb2202f70594d5dde13493af62dcad.camel@redhat.com> <2023063001-agenda-spent-83c6@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Fri, 30 Jun 2023 20:42:28 +0000 Long Li wrote: > > > 5.15 and kernel 6.1. (those kernels are longterm) They need this fix to achieve > > > the performance target. > > > > Why can't they be upgraded to get that performance target, and all the other > > goodness that those kernels have? We don't normally backport new features, > > right? > > I think this should be considered as a fix, not a new feature. > > MANA is designed to be 200GB full duplex at the start. Due to lack of > hardware testing capability at early stage of the project, we could only test 100GB > for the Linux driver. When hardware is fully capable of reaching designed spec, > this bug in the Linux driver shows up. That part we understand. If I were you I'd try to convince Greg and Paolo that the change is small and significant for user experience. And answer Greg's question why upgrading the kernel past 6.1 is a challenge in your environment.