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 X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16268C433E1 for ; Mon, 22 Jun 2020 15:55:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E28ED2074D for ; Mon, 22 Jun 2020 15:55:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EvGNCxzN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729537AbgFVPzZ (ORCPT ); Mon, 22 Jun 2020 11:55:25 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:43932 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729260AbgFVPzY (ORCPT ); Mon, 22 Jun 2020 11:55:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592841321; 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: in-reply-to:in-reply-to:references:references; bh=5/TWvdWyq1xUujhnrnIglEliiwBVOZjUqDPRZt1W7a0=; b=EvGNCxzN1uQHAp1yoGxQPmcdeJ5SafYVYv3Aekx03iVu29tnQHoBUAvZXw6vagtudaJrTg 4CMVd6CZyW7q8MiAutdbWZ1lzFQj/Bb/+ixh1pWyVYOcdXIExj0ut0yjsnJJM+Jsk9PlnB 4ox9F6t4KuhHW4N0B4QGCvPxUcXbbs0= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-247-qYpXKjRzOE2M29TVhBgLuA-1; Mon, 22 Jun 2020 11:55:10 -0400 X-MC-Unique: qYpXKjRzOE2M29TVhBgLuA-1 Received: by mail-wr1-f69.google.com with SMTP id r5so11140649wrt.9 for ; Mon, 22 Jun 2020 08:55:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=5/TWvdWyq1xUujhnrnIglEliiwBVOZjUqDPRZt1W7a0=; b=ggOrhIAFQ7auUV6zHyglavkeQ23PGjHX5L1VDAdI7yb7PewIaQkCmqDRq/uYpC6uX2 XCUIOCxXAY+ct5wNhveF87r7ARwAFJUzLfOs/WGPo6Fscvf/kBaAmRUSzv801GEKgAIq LdvbPCkPdSldAsjFCOUPU/1sWrXuw6jGk+EfAiA4PJJ5HinIPsRDObS7B4z8H13sTU+U Zw1esQG1kMrDu5bVMAvWHOzEJkHu/1lbU153cquSpukA4zfG6d1yBGHYR0NVs0PoFF5q T5vjMmzKmnkj1mHp7OayIA5RIk118veTCPDn+qzHfWrWF6RIjsJptIM1ATeTAwOwQlf5 yinQ== X-Gm-Message-State: AOAM531pUfnHsviCjqoyxx2pPEwlqy7u1ZlYrbzhjzmzl+VbGx05gIyK oCcmH1g7A6WuVulCpmYfW8XjBN9iSUmyUukY2+FnBGzSCaJK/g0wFhNYleFmv2TBgwRxXyujC7K 3P7dY2gdpoS6dhq4J X-Received: by 2002:adf:81c8:: with SMTP id 66mr15414790wra.348.1592841308601; Mon, 22 Jun 2020 08:55:08 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzDqUXaq8ZLWjDVbqp55FyjxeMofHg+9iAPblS6Tpzqu1HcZ9tDlKdMVd5PLYKsZyiUVy0W0Q== X-Received: by 2002:adf:81c8:: with SMTP id 66mr15414773wra.348.1592841308364; Mon, 22 Jun 2020 08:55:08 -0700 (PDT) Received: from redhat.com (bzq-79-178-18-124.red.bezeqint.net. [79.178.18.124]) by smtp.gmail.com with ESMTPSA id d201sm5593758wmd.34.2020.06.22.08.55.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Jun 2020 08:55:07 -0700 (PDT) Date: Mon, 22 Jun 2020 11:55:04 -0400 From: "Michael S. Tsirkin" To: Eugenio Perez Martin Cc: Konrad Rzeszutek Wilk , linux-kernel@vger.kernel.org, kvm list , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, Jason Wang Subject: Re: [PATCH RFC v8 02/11] vhost: use batched get_vq_desc version Message-ID: <20200622114622-mutt-send-email-mst@kernel.org> References: <20200611113404.17810-1-mst@redhat.com> <20200611113404.17810-3-mst@redhat.com> <20200611152257.GA1798@char.us.oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Jun 19, 2020 at 08:07:57PM +0200, Eugenio Perez Martin wrote: > On Mon, Jun 15, 2020 at 2:28 PM Eugenio Perez Martin > wrote: > > > > On Thu, Jun 11, 2020 at 5:22 PM Konrad Rzeszutek Wilk > > wrote: > > > > > > On Thu, Jun 11, 2020 at 07:34:19AM -0400, Michael S. Tsirkin wrote: > > > > As testing shows no performance change, switch to that now. > > > > > > What kind of testing? 100GiB? Low latency? > > > > > > > Hi Konrad. > > > > I tested this version of the patch: > > https://lkml.org/lkml/2019/10/13/42 > > > > It was tested for throughput with DPDK's testpmd (as described in > > http://doc.dpdk.org/guides/howto/virtio_user_as_exceptional_path.html) > > and kernel pktgen. No latency tests were performed by me. Maybe it is > > interesting to perform a latency test or just a different set of tests > > over a recent version. > > > > Thanks! > > I have repeated the tests with v9, and results are a little bit different: > * If I test opening it with testpmd, I see no change between versions OK that is testpmd on guest, right? And vhost-net on the host? > * If I forward packets between two vhost-net interfaces in the guest > using a linux bridge in the host: And here I guess you mean virtio-net in the guest kernel? > - netperf UDP_STREAM shows a performance increase of 1.8, almost > doubling performance. This gets lower as frame size increase. > - rests of the test goes noticeably worse: UDP_RR goes from ~6347 > transactions/sec to 5830 OK so it seems plausible that we still have a bug where an interrupt is delayed. That is the main difference between pmd and virtio. Let's try disabling event index, and see what happens - that's the trickiest part of interrupts. > - TCP_STREAM goes from ~10.7 gbps to ~7Gbps > - TCP_RR from 6223.64 transactions/sec to 5739.44