From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?B?5pyx6I+B?= Subject: a strange bcache0 100% busy with no IO rw and no cpu consumption Date: Sun, 14 May 2017 11:20:59 +0800 Message-ID: <002a01d2cc61$1c249820$546dc860$@ecloudtech.com.cn> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8BIT Return-path: Received: from smtpbguseast2.qq.com ([54.204.34.130]:47136 "EHLO smtpbguseast2.qq.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754104AbdENDUv (ORCPT ); Sat, 13 May 2017 23:20:51 -0400 Content-Language: en-us Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: linux-bcache@vger.kernel.org Cc: qlg@ecloudtech.com.cn Hi,all [root@scst-test bcache]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT dfa 250:0 0 1.1T 0 disk └─dfa1 250:1 0 1.1T 0 part └─bcache0 249:0 0 21.8T 0 disk ├─vg_bcache0-fc_vol3 253:3 0 4T 0 lvm ├─vg_bcache0-fc_vol4 253:4 0 4T 0 lvm ├─vg_bcache0-fc_vol5 253:5 0 4T 0 lvm └─vg_bcache0-fc_vol6 253:6 0 4T 0 lvm sda 8:0 0 557.8G 0 disk ├─sda1 8:1 0 1G 0 part /boot └─sda2 8:2 0 556.8G 0 part ├─cl-root 253:0 0 50G 0 lvm / ├─cl-swap 253:1 0 4G 0 lvm [SWAP] └─cl-home 253:2 0 502.8G 0 lvm /home sdb 8:16 0 21.8T 0 disk └─sdb1 8:17 0 21.8T 0 part └─bcache0 249:0 0 21.8T 0 disk ├─vg_bcache0-fc_vol3 253:3 0 4T 0 lvm ├─vg_bcache0-fc_vol4 253:4 0 4T 0 lvm ├─vg_bcache0-fc_vol5 253:5 0 4T 0 lvm └─vg_bcache0-fc_vol6 253:6 0 4T 0 lvm [root@scst-test bcache]# modinfo bcache filename: /lib/modules/4.4.65-1.el7.elrepo.x86_64/kernel/drivers/md/bcache/bcache.ko license: GPL author: Kent Overstreet author: Kent Overstreet license: GPL srcversion: 391A0B3836FE95B29F75289 depends: intree: Y vermagic: 4.4.65-1.el7.elrepo.x86_64 SMP mod_unload modversions my testing case: node1: stor-node, running scst target with bcache ( 1.2T pcie-ssd  cache device, 21T lsi raid10 lun backing device) node2: esxi-node, running FIO testing in a VM(rhel6.5) at first i have done about 100T 128k randwrite benchmarking on bcache0 device [root@localhost ~]# cat myfio.sh i=0 while [ $i -le 99 ] do fio --filename=/dev/sdb --rw=randwrite --bs=128k --ioengine=libaio --iodepth=16 --randrepeat=0 --refill_buffers --norandommap --size=1024G -name=test --numjobs=1 sleep 5 let i=i+1 done then stop all application,clean all dirty_data,set cache_mode to none, set writeback_runing to 0. and then checking sysfs state. [root@scst-test bcache]# service scst stop [root@scst-test bcache]# cat dirty_data 0 [root@scst-test bcache]# cat state clean [root@scst-test bcache]# cat writeback_percent 0 [root@scst-test bcache]# cat writeback_running 1 [root@scst-test bcache]# echo 0 > writeback_running [root@scst-test bcache]# cat writeback_running 0 [root@scst-test bcache]# cat cache_mode writethrough writeback writearound [none] <<