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=-0.9 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 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 0CC9FC433E0 for ; Fri, 10 Jul 2020 05:58:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA4DD2076A for ; Fri, 10 Jul 2020 05:58:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Y+XxOvBj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726328AbgGJF6b (ORCPT ); Fri, 10 Jul 2020 01:58:31 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:53179 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725802AbgGJF6a (ORCPT ); Fri, 10 Jul 2020 01:58:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594360708; 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=C4LnrvqT9+DNx24YkEZw2+SXe1o6FKiLlzwpTypzG8A=; b=Y+XxOvBjEbl9F7XdtOTWEY97JVlA/4JP9m1OmOM/D/jNmDESGG8eUGLrkYTpi8iDjHO65f DcJzt/9EtJvnxVr49HXpyCfTyPviqACGraWwl9LAp+nvbzYOwfs3ZJ/2BEaJ1Ey//5I0mk Ry4yH4AO8/XNtQnB4TbTvmqSHnhav1M= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-259-ZD-6VCJxNga62OFj6PP7Kg-1; Fri, 10 Jul 2020 01:58:26 -0400 X-MC-Unique: ZD-6VCJxNga62OFj6PP7Kg-1 Received: by mail-wm1-f70.google.com with SMTP id q20so5291623wme.3 for ; Thu, 09 Jul 2020 22:58:26 -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=C4LnrvqT9+DNx24YkEZw2+SXe1o6FKiLlzwpTypzG8A=; b=IU4gcZw2Bz8yi76ZBgtKzCAv2CX6gA2K3TvA1Aean6YYLK1Fcu7h+fG8koxRX7dAt8 gf6uVW7ZdOjdFbEd8oexj5FSf18LI0i/EKMeB5LC1OHDT0VS4LefrOQdidJmUm5t6bCK TXv0TRE38L4BEKGwiHnHqyRenr6/gV9aJ3Idg+uW5+PmSlK+Da5XTeg9cZpXVf1kuCxW WX+e/qzzeA02dvzDT2iKWicH7e5YKokQIF0AzPsQo0RgMBuUnpdJYI2olq5lIE6/hcwt 4UrVWahfg8/rWeVpCYezqG4blvv9PS1iF48F9cKNwsklwvOA+D++B0q32rWlxCvQyRw9 jc1A== X-Gm-Message-State: AOAM533QomKyHfqJxqpU3Wcj3rlRzaSK9OwrkYbRDfe+eX6/6Eff3m/l xTrWqwK2Etm3xgsUhnDZujeOKkvgEP8rhZpt2Ye3vfaIhK1YfFDV4cazWynSvBXrKgFYmJRzq0+ 0J+gWI1qtVUfdp23p X-Received: by 2002:a7b:c38f:: with SMTP id s15mr3394782wmj.152.1594360705672; Thu, 09 Jul 2020 22:58:25 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwLn6mDVLNvrd8u4soiaqjHIlkFvr4sTxn75hYjrWzq/00SA7DFxiythkthHZ5njp79o9gOug== X-Received: by 2002:a7b:c38f:: with SMTP id s15mr3394766wmj.152.1594360705488; Thu, 09 Jul 2020 22:58:25 -0700 (PDT) Received: from redhat.com (bzq-79-182-31-92.red.bezeqint.net. [79.182.31.92]) by smtp.gmail.com with ESMTPSA id j15sm8366155wrx.69.2020.07.09.22.58.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jul 2020 22:58:24 -0700 (PDT) Date: Fri, 10 Jul 2020 01:58:21 -0400 From: "Michael S. Tsirkin" To: Eugenio Perez Martin Cc: Jason Wang , Konrad Rzeszutek Wilk , linux-kernel@vger.kernel.org, kvm list , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org Subject: Re: [PATCH RFC v8 02/11] vhost: use batched get_vq_desc version Message-ID: <20200710015615-mutt-send-email-mst@kernel.org> References: <20200622122546-mutt-send-email-mst@kernel.org> <419cc689-adae-7ba4-fe22-577b3986688c@redhat.com> <0a83aa03-8e3c-1271-82f5-4c07931edea3@redhat.com> <20200709133438-mutt-send-email-mst@kernel.org> <7dec8cc2-152c-83f4-aa45-8ef9c6aca56d@redhat.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, Jul 10, 2020 at 07:39:26AM +0200, Eugenio Perez Martin wrote: > > > How about playing with the batch size? Make it a mod parameter instead > > > of the hard coded 64, and measure for all values 1 to 64 ... > > > > > > Right, according to the test result, 64 seems to be too aggressive in > > the case of TX. > > > > Got it, thanks both! In particular I wonder whether with batch size 1 we get same performance as without batching (would indicate 64 is too aggressive) or not (would indicate one of the code changes affects performance in an unexpected way). -- MST