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=-2.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 EE67BC35240 for ; Fri, 24 Jan 2020 01:14:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B91A12087E for ; Fri, 24 Jan 2020 01:14:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="fzaaW/KZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729151AbgAXBOZ (ORCPT ); Thu, 23 Jan 2020 20:14:25 -0500 Received: from mail-pg1-f195.google.com ([209.85.215.195]:40117 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730302AbgAXBOY (ORCPT ); Thu, 23 Jan 2020 20:14:24 -0500 Received: by mail-pg1-f195.google.com with SMTP id k25so145627pgt.7 for ; Thu, 23 Jan 2020 17:14:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.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=d/C7aUYJTHQhwaao3+gD60wS4QAXQx/hM6I1wIffSJs=; b=fzaaW/KZ9B8G71DauBM19VGPslUtbmlIYJKyYq7ZLBp7hAgRlB8x5Nt5mAK2+ai8xZ ktZ2YPKJ5HoZIJVecr2xPjPLbKnpZ8ZENdvMQjXVDQect5BUXD2amTQp8Z60i5u10MGu Vyvqg6hqC/jgdKlZ2bubRyMekAOoUL7wBvWrwt2FHGxVhXbGa3lc58JgfEUju1u17imP BtZll8y4O7yvc+CtBnQn0IMnKxQKMLTMOhl4XQ7cR/bLcWpclAQiMZ07lHmAFvCeXemH dpdmybADm8KYCBhH/EMneVoXA7fJLK6rmPKuL3Hx+yeb/w3THHLVPKiYNCnOvml21KJT Khmg== 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=d/C7aUYJTHQhwaao3+gD60wS4QAXQx/hM6I1wIffSJs=; b=UKLybPPqvEocYpfRFOcoi8/gNkdvBSLZLWxQheUKy1uiPteREbsoS9eRqDXMxgZ63J bgTryTwKbge8FNXDf0x2p4VQZVD/ebu7wwTxCzAEFGcC/798EpMPPwGGrXpsDCY9rCE0 OvfZt6awe0MXxK/5UzGClCYxtfhWE7CNG7Zey0M9szVl3wrNzeUWuMvn8FMehwfu9Hi/ sPkvh05H4HQuq6cpURG4uKFgpAZvfuNQqAOYXZMBlXORwq6QsM7DslBfapwSZxC3R2Cf 1Cq06UaWymY8A836yjK6zq5zJeQV6e+TYhf4tWIMxeI/wxwJvXZOuOksSyn9oVcmQL0E /SKQ== X-Gm-Message-State: APjAAAXw++b+Q3qH5mHIOCB8D7l3JyrKJPZK9d1XwN19GybNVZS9FG60 7lXiRYwEdPNp3UIc8CGXmfKhwA== X-Google-Smtp-Source: APXvYqx720e+PGy1MaQyQL/p07/L46E8myHpIewE7Rg1kzPHTOVVKdsC8DRLM0DeGQr+4z7FsjUojw== X-Received: by 2002:aa7:9d87:: with SMTP id f7mr978368pfq.138.1579828463979; Thu, 23 Jan 2020 17:14:23 -0800 (PST) Received: from [192.168.201.136] ([50.234.116.4]) by smtp.gmail.com with ESMTPSA id q6sm3770589pfh.127.2020.01.23.17.14.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 23 Jan 2020 17:14:23 -0800 (PST) Subject: Re: [PATCH 14/17] bcache: back to cache all readahead I/Os To: Coly Li Cc: Michael Lyle , linux-bcache , linux-block@vger.kernel.org, stable References: <20200123170142.98974-1-colyli@suse.de> <20200123170142.98974-15-colyli@suse.de> <31f7f6b4-98ea-3cf6-44cc-a9ba67484eb0@kernel.dk> <6373da22-9dc1-9525-4048-2c533407c917@suse.de> From: Jens Axboe Message-ID: <6d72473b-db79-d32a-055c-05a34f2d2b12@kernel.dk> Date: Thu, 23 Jan 2020 18:14:22 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <6373da22-9dc1-9525-4048-2c533407c917@suse.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 1/23/20 5:49 PM, Coly Li wrote: > On 2020/1/24 2:31 上午, Jens Axboe wrote: >> On 1/23/20 10:27 AM, Coly Li wrote: >>> On 2020/1/24 1:19 上午, Michael Lyle wrote: >>>> Hi Coly and Jens-- >>>> >>>> One concern I have with this is that it's going to wear out >>>> limited-lifetime SSDs a -lot- faster. Was any thought given to making >>>> this a tunable instead of just changing the behavior? Even if we have >>>> an anecdote or two that it seems to have increased performance for >>>> some workloads, I don't expect it will have increased performance in >>>> general and it may even be costly for some workloads (it all comes >>>> down to what is more useful in the cache-- somewhat-recently readahead >>>> data, or the data that it is displacing). >>> >>> Hi Mike, >>> >>> Copied. This is good suggestion, I will do it after I back from Lunar >>> New Year vacation, and submit it with other tested patches in following >>> v5.6-rc versions. >> >> Do you want me to just drop this patch for now from the series? >> > Hi Jens, > > OK, please drop this patch from this series. I will re-submit the patch > with sysfs interface later with other patches. Sounds good, I queued up the rest for 5.6. -- Jens Axboe