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=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 2A8C8C4360C for ; Wed, 3 Mar 2021 00:35:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE2BA64FB5 for ; Wed, 3 Mar 2021 00:35:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234470AbhCCASV (ORCPT ); Tue, 2 Mar 2021 19:18:21 -0500 Received: from mout.gmx.net ([212.227.17.22]:56839 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379962AbhCBKWe (ORCPT ); Tue, 2 Mar 2021 05:22:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1614680430; bh=EUSMcnw5u/o+Z6hT7LQOufUgCnNkWu4J1JQzsagLmqc=; h=X-UI-Sender-Class:To:Cc:From:Subject:Date; b=IuwDsqsb9L+rW5w9PlJxixE0u+jN08tdSZcgxObEhYL5eL7CCfvfzZ3pK4JmDRruD 67atTZ9vxn4CNB0drVrrCVYc329yaV+oA8xJ1GLHBhnUk5mSuDwd4pBudq86ACIi2x UgkDnSupRKd9AB+NERls/2nIY/NE+jaOxHJxRMiI= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [10.10.213.91] ([103.52.188.137]) by mail.gmx.net (mrgmx104 [212.227.17.174]) with ESMTPSA (Nemesis) id 1MK3Rm-1lUrlD221O-00LYO2; Tue, 02 Mar 2021 11:20:30 +0100 To: Coly Li Cc: linux-bcache@vger.kernel.org, linux-block@vger.kernel.org From: "Norman.Kern" Subject: Large latency with bcache for Ceph OSD(new mail thread) Message-ID: <9b7dfd49-67b0-53b1-96e1-3b90c2d9d09a@gmx.com> Date: Tue, 2 Mar 2021 18:20:25 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Content-Language: en-US X-Provags-ID: V03:K1:k+4Miwh80poaIHYO/bhJibu4nYsd4O1YdR/pm1MgII1iBgBXz5d bkALxAJD4jQMoJ9mPZBze2ylMYaIe22Aep6pNvMRo4wl/c8dqstc2EI6YbaQiLT8uOSEIUW 4dul7Yv2SwEJtQahZTVjqhOT2/tBXIiOzsYH2SpP8WwX7FO7sb5TspgiWUelKgpTvnLG6iX Q78Yx+VbmeBOzCno4c6QQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:BJxmL4zPfo4=:kc4yx+y0T9ezrx8MLWcw2W lU30R+y3uv/pEKCo2wqbqUrOwvTtHZAXDWuzZ3Oo1tbnLrGiE1hUW0kUmKNpDIJW/iAyIk/pv 6+7Zk5KMfIuSrdSwMVCthLolEGfSvA39XAAyNqIo40U1MtSa7jSamgfOkg/uF09ciQxORf/xH NUPubIBzIvkF6TwWxWefDXXVJgOQJZqej9hNq3fNiOO+8QUImzYs4ZRx+W22cfhoNsDd6WNB4 FvJSPGAsB2Ll/5ta4cZseNhbzmtRoF7UfYsl3rYQLG3wFQpHj/VfDYfflRZBwfVIkeXxMNCXp NaPCikTgaPBS1caNW5nB/zM3zHX4DXZfUsIXcXcN+L28R5858hgRFn9WsZXC1Hzxvtb+V7AzZ 3oEsa0bYGoD/Inyioef/yBEaFXGYZpUJJOf/FdgHeeddhdCpdlzMa8471qWp+FcKZxjeD9Xoq qA4ji7XO0Dn1hdiQfYY1NiQaBew+OpESQ2akT2ulNxwHUU9kiXX7NgzWLVagsNC9tCff75YVl YLdO9k+dhY1WUQnyRvsj5Z5q5VMGATvfKCI+IDhBdb8dSwZE1Y3xrO1vkCURdbYoNGquiGvoE rLM0patp7R4AaEKN6UD68hRdWwaOJaMOt4uyZFWmVIMGiais4gxwmttStXPq+Y3TGmG0VwLG4 rm5Kt4eOMeU2GszJ5PlWaf5iWsghbR7eRuEDwLr6SrRwum79bYPhCIV+mAP24Em0wGk/ukOAG YvmJWAgOTIjb/HDiTE7ODkhfqh/dh/SfBnRBGvqBYPLlwdAVyW/dAcipJR3AISAPYjc7NiOml b9ogTHKkwc+/jlrfnv17yMVvWs76i6igKjjO9sd5tXUFctxHUplDuwN3U7um+XC0iK8fdGZNG nA4JBkLfk9CN1vkpxrLQ== Precedence: bulk List-ID: X-Mailing-List: linux-bcache@vger.kernel.org Sorry for creating a new mail thread(the origin is so long...) I made a test again and get more infomation: root@WXS0089:~# cat /sys/block/bcache0/bcache/dirty_data 0.0k root@WXS0089:~# lsblk /dev/sda NAME=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 MAJ:MIN RM=C2=A0=C2=A0 SIZE RO TYPE MOU= NTPOINT sda=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 8:0=C2=A0=C2=A0=C2=A0 = 0 447.1G=C2=A0 0 disk `-bcache0 252:0=C2=A0=C2=A0=C2=A0 0=C2=A0 10.9T=C2=A0 0 disk root@WXS0089:~# cat /sys/block/sda/bcache/priority_stats Unused:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 1% Clean:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 29% Dirty:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 70% Metadata:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 0% Average:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 49 Sectors per Q:=C2=A0 29184768 Quantiles:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 [1 2 3 5 6 8 9 11 13 14 16 19 21 = 23 26 29 32 36 39 43 48 53 59 65 73 83 94 109 129 156 203] root@WXS0089:~# cat /sys/fs/bcache/066319e1-8680-4b5b-adb8-49596319154b/in= ternal/gc_after_writeback 1 You have new mail in /var/mail/root root@WXS0089:~# cat /sys/fs/bcache/066319e1-8680-4b5b-adb8-49596319154b/ca= che_available_percent 28 I read the source codes and found if cache_available_percent > 50, it shou= ld wakeup gc while doing writeback, but it seemed not work right.