From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1014F5479F for ; Mon, 25 Mar 2024 02:21:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711333295; cv=none; b=QGalEYnS/j8DAaCF94mzSZxp/+Eg/kNAtiS4g/tg/JpWoeC32k4phO4qn5GOrSve8AC9kq6hU6aVZ/b//JATCBaHXfnyL3icrD7ZV0PprwWz1ElK9jEM9LpjN/lFSUiqq91CRvp9UXLd/zZy8VCTJ+1S5F77vIw/H1j2sXQTUx0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711333295; c=relaxed/simple; bh=O55hfeRrM8Nyva7hubsFry8A4/QGu0XdVfEA6z4VZmY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=CshLIC66uKSy/JSewTDwidB5W6IA82OTPloUB+3WIjljan72woSZCVpEsXzUZIbwM9GzGxz3/KRJm9iKJYSMM1ki3tpFNIT4toYFWAI1n/sBH6yrmeC5fTGRQZt7afVxDZXnZpBadvzGAPUv+peixKGrsaGeylE3G/nTmc6bBn0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=uDdh0wSq; arc=none smtp.client-ip=115.124.30.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="uDdh0wSq" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1711333290; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=P3YrW/OUqxaVBghKQR22O4dIfIzNVTvbEPAdpxgPbw4=; b=uDdh0wSqyOKKQbWOLmE+7KSMsKBJjiTaISQA1HuqhaCS1ylErYQgzyfikkkds6zvEzwuhWXpL3gFqqQ+xpWBbJTH7EIBtsEcxVWsvRnQveJ+WOR4U3AB0wwfbZ+XnLEVcCjCQYIiofdoQTOwymlt4mZNbMzz7MjnFpZJxK4Rax4= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R651e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046051;MF=hengqi@linux.alibaba.com;NM=1;PH=DS;RN=9;SR=0;TI=SMTPD_---0W38IF0._1711333286; Received: from 30.221.148.153(mailfrom:hengqi@linux.alibaba.com fp:SMTPD_---0W38IF0._1711333286) by smtp.aliyun-inc.com; Mon, 25 Mar 2024 10:21:29 +0800 Message-ID: <5708312a-d8eb-40ee-88a9-e16930b94dda@linux.alibaba.com> Date: Mon, 25 Mar 2024 10:21:23 +0800 Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] virtio-net: reduce the CPU consumption of dim worker To: Jason Wang Cc: netdev@vger.kernel.org, virtualization@lists.linux.dev, "Michael S. Tsirkin" , Jakub Kicinski , Paolo Abeni , Eric Dumazet , "David S. Miller" , Xuan Zhuo References: <1711021557-58116-1-git-send-email-hengqi@linux.alibaba.com> <1711021557-58116-3-git-send-email-hengqi@linux.alibaba.com> From: Heng Qi In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 在 2024/3/22 下午1:19, Jason Wang 写道: > On Thu, Mar 21, 2024 at 7:46 PM Heng Qi wrote: >> Currently, ctrlq processes commands in a synchronous manner, >> which increases the delay of dim commands when configuring >> multi-queue VMs, which in turn causes the CPU utilization to >> increase and interferes with the performance of dim. >> >> Therefore we asynchronously process ctlq's dim commands. >> >> Signed-off-by: Heng Qi > I may miss some previous discussions. > > But at least the changelog needs to explain why you don't use interrupt. Will add, but reply here first. When upgrading the driver's ctrlq to use interrupt, problems may occur with some existing devices. For example, when existing devices are replaced with new drivers, they may not work. Or, if the guest OS supported by the new device is replaced by an old downstream OS product, it will not be usable. Although, ctrlq has the same capabilities as IOq in the virtio spec, this does have historical baggage. Thanks, Heng > > Thanks