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=-3.9 required=3.0 tests=BAYES_00,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 195D5C4727E for ; Wed, 7 Oct 2020 16:28:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CC192064E for ; Wed, 7 Oct 2020 16:28:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=purestorage.com header.i=@purestorage.com header.b="L702T7Ea" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726138AbgJGQ2N (ORCPT ); Wed, 7 Oct 2020 12:28:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726105AbgJGQ2M (ORCPT ); Wed, 7 Oct 2020 12:28:12 -0400 Received: from mail-qt1-x836.google.com (mail-qt1-x836.google.com [IPv6:2607:f8b0:4864:20::836]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B592BC061755 for ; Wed, 7 Oct 2020 09:28:12 -0700 (PDT) Received: by mail-qt1-x836.google.com with SMTP id j22so2380167qtj.8 for ; Wed, 07 Oct 2020 09:28:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=purestorage.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=r6+uO8I2VW2mJGYPdvvwjqBKkpdtpb+OLtWSFFZnN1E=; b=L702T7Ea3ozZq59JPUKLNjoZU79TmQSIiFHEzTZy2zFB16HMwPkQ3nEzx6CC9cdI4r /Z4hmZ6J6sLyU6MuGVH1P2sF9p0kJyJT4e9a4on3z+e0j9lcG6pK2tGaUFP+R1g9cVUB Tq1QUAfcfH18+FRyOzq5qnIFlhLSqfhIO7RqE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=r6+uO8I2VW2mJGYPdvvwjqBKkpdtpb+OLtWSFFZnN1E=; b=MOEcMz6v25/zs+MyfUlJ+uAB8E6RbdzVH6SNOHkt0ZHuYQ+UcRx40Vo2XFlu3RiG0D nWHN0bLVPtjpkZhZ4fx4qJr8+o94jDLljofA7nIB7YsmJ6BKvJjkAdJsLjV8Aa2IbhA1 Uw4xxKoxZG8ZtKQrxyOm4J0FA9l4zhLNRSKvu+maMBzQ3WxVrZrzYzKyaOZLretL2VhQ +/ijE1NgvAd1CDY3RaxnDmKyAst2YpFCWHqJjuW0+BOs3W3hNppicTv+dZQdI5BheN55 Uu5fILgCUSDdGXX5j0c07yYA+L8+SW0XH1U1ePKQrh1/rGWwDtaJhZv6JxTPi5o47K8e cjaw== X-Gm-Message-State: AOAM533M7zVvMoPpS0kqdwU9VagaGifT4oOvUH/2yfyiTt1uVyRNuFbQ 4mcqfh0T0bvC86hJjOd9lSn7+M7wY3oiwacz57a0ig== X-Google-Smtp-Source: ABdhPJyTWYzpFkOU6dfkHq9ZMfycgJ7qopzsyf+l5TT8Qpe4FIBTlUwp5byjkLTCNKpKHSxFgImJwDrhYB8IUIznAek= X-Received: by 2002:ac8:100c:: with SMTP id z12mr3924480qti.81.1602088091738; Wed, 07 Oct 2020 09:28:11 -0700 (PDT) MIME-Version: 1.0 References: <20201006151335.GB28306@fieldses.org> In-Reply-To: From: Igor Ostrovsky Date: Wed, 7 Oct 2020 09:28:00 -0700 Message-ID: Subject: Re: unsharing tcp connections from different NFS mounts To: Patrick Goetz Cc: "J. Bruce Fields" , Linux NFS Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Wed, Oct 7, 2020 at 6:57 AM Patrick Goetz wrote: > I don't see how sharing a TCP connection can result in a performance > regression (the performance degradation of *not* sharing a TCP > connection is why HTTP 1.x is being replaced), or how using different IP > addresses on the same interface resolves anything. Does anyone have an > explanation? > The two IPs give you a form of QoS. So, it's about performance isolation across the mounts, not about improving the aggregate performance. The example I mentioned was this one: dd if=/dev/zero of=/mnt/mount1/zeros & ls /mnt/mount2/ The writes to /mnt/mount1 keep the transport busy transmitting data. As a result, the "ls" GETATTR (or whatever RPC) needs to wait on the single transport, potentially for seconds. Putting the two mounts on different IPs solves the problem, at least prior to trunking discovery.