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=-6.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 5C117C388F7 for ; Wed, 28 Oct 2020 22:26:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3988206F4 for ; Wed, 28 Oct 2020 22:26:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=toxicpanda-com.20150623.gappssmtp.com header.i=@toxicpanda-com.20150623.gappssmtp.com header.b="vl0DAxTx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732892AbgJ1WZX (ORCPT ); Wed, 28 Oct 2020 18:25:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54876 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732874AbgJ1WZV (ORCPT ); Wed, 28 Oct 2020 18:25:21 -0400 Received: from mail-qt1-x843.google.com (mail-qt1-x843.google.com [IPv6:2607:f8b0:4864:20::843]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45C11C0613CF for ; Wed, 28 Oct 2020 15:25:21 -0700 (PDT) Received: by mail-qt1-x843.google.com with SMTP id r8so670974qtp.13 for ; Wed, 28 Oct 2020 15:25:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=XDKshFT67w1TenH4xvDZOT2AucE4MpYkvogvdq8G1fc=; b=vl0DAxTxmkgeJ+6HsOLP+O6KW4mdtJpR5rcPedZkMV9Ajv1+T7MEz88qWTw45FuKmr SNHwfIkqXsuHP8u3MjrLnXICQ10Vb4+B4gLujOwdu2182O0OwMF0P2OXOGEQXSP0nued ECyLuqxFDI/bJCm9rSZvbeW6m3jaEOxkQ5q+IMVX1KnL6KbEvCwKmV9MLZL2Ff5uFsCc 7/809fIAG6R/iqwCr/RQ3/jd1HzOfuVifpyP+2Wk8KNAh8MRGoeUmftBHuyAPx9N5k5v 83JMzJEw1uM6OmYkkyZnXXHKcixXSBxbP6yFd/+W/K0FNns7brC+LUPGxcOFf9DrW7hM 3cgg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=XDKshFT67w1TenH4xvDZOT2AucE4MpYkvogvdq8G1fc=; b=lYZ0T4cp/Pmie6LFXI1UsHDDkmkzqYk3AgLPv7EkfJ/icAngiwgLwt44ULnpkAKBLi M2WEo3ouNiubWPLHvb69biDNbP54K1iDbbVzMXtyc8+MCjuJEbE9+4t2VdLhMPPNAh6H XA1t22oSyEkc9WJ7D5fUUs3V32ONMZCtpNb8NfeYjamYBWpCPUVb4+bMe7P7lXSKhUfU pGpWU6QI1vvP8WVNexsXYKRNs8ShdM7YV6HhFx7m/ODqeBPXGY1DpqxzvxUbhXjSBOE9 cJ9mFG2WcFCINEwTH1EdcXsKpQdgsdETfBymexO1d5nIEASYTF5J0gE2BLjhajxdbidl vqcQ== X-Gm-Message-State: AOAM5335Lt7R1mRXMWG/ihNm+jrv3RaQ5KoKo99CdJqUUtrclbZdhweQ fcz/1P2sp5vCAkw3VkhZG1ZAUffk/M4Ztd1o X-Google-Smtp-Source: ABdhPJx6HXLC2P/UI4H0UJXR9RRicrgptDyVwekrMhUwGVz0qhtr+Pn7qpYqA7ugB+Gs5aSwVOUEXw== X-Received: by 2002:a05:620a:127a:: with SMTP id b26mr7690466qkl.166.1603895522277; Wed, 28 Oct 2020 07:32:02 -0700 (PDT) Received: from [192.168.1.45] (cpe-174-109-172-136.nc.res.rr.com. [174.109.172.136]) by smtp.gmail.com with ESMTPSA id 63sm3088772qkn.9.2020.10.28.07.32.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 28 Oct 2020 07:32:01 -0700 (PDT) Subject: Re: [PATCH v1 0/4] btrfs: read_policy types latency, device and round-robin To: Anand Jain , linux-btrfs@vger.kernel.org Cc: dsterba@suse.com References: From: Josef Bacik Message-ID: Date: Wed, 28 Oct 2020 10:32:00 -0400 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 10/28/20 9:25 AM, Anand Jain wrote: > Based on misc-next > > Depends on the following 3 patches in the mailing list. > btrfs: add btrfs_strmatch helper > btrfs: create read policy framework > btrfs: create read policy sysfs attribute, pid > > v1: > Drop tracing patch > Drop factoring inflight command > Here below is the performance differences, when inflight is used, it pushed > few commands to the other device, so losing the potential merges. > > with inflight: > READ: bw=195MiB/s (204MB/s), 195MiB/s-195MiB/s (204MB/s-204MB/s), io=15.6GiB (16.8GB), run=82203-82203msec > sda 256054 > sdc 20 > > without inflight: > READ: bw=192MiB/s (202MB/s), 192MiB/s-192MiB/s (202MB/s-202MB/s), io=15.6GiB (16.8GB), run=83231-83231msec > sda 141006 > sdc 0 > What's the baseline? I think 3mib/s is not that big of a tradeoff for complexity, but if baseline is like 190mib/s then maybe its worth it. If baseline is 90mib/s then I say it's not worth the inflight. Thanks, Josef