From mboxrd@z Thu Jan 1 00:00:00 1970 From: tang.junhui@zte.com.cn Subject: Re: kernel hangs and crashes with 4.15 (also 4.13, 4.14) Date: Mon, 12 Feb 2018 19:29:03 +0800 Message-ID: <1518434943-6895-1-git-send-email-tang.junhui@zte.com.cn> Return-path: Received: from out1.zte.com.cn ([202.103.147.172]:59726 "EHLO mxct.zte.com.cn" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933898AbeBLL0a (ORCPT ); Mon, 12 Feb 2018 06:26:30 -0500 Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: bcache@mfedv.net Cc: linux-bcache@vger.kernel.org, tang.junhui@zte.com.cn From: Tang Junhui Hello Matthias, Thanks for your detail information, I will try to reproduce this issue in my machine, but I am sorry that It would be 10 days later because the Spring Festival holiday is comming. I also hope somebody would resolve this problem before I am back. > > On Mon, Feb 12, 2018 at 04:57:52PM +0800, tang.junhui@zte.com.cn wrote: > > > From: Tang Junhui > > > > > > > > > Hello Matthias, > > > > > > What kind of caching mode do you use? Writeback or Writethrough? > > > > Hi, thanks for looking into this. > > > > This is with writeback caching (haven't tried writethrough yet). > > > > Some more info about the disk drives used: > > > > # ls -l /dev/disk/by-id | grep -v -- -part | grep -v wwn- > > total 0 > > lrwxrwxrwx 1 root root 9 Feb 8 00:48 ata-INTEL_SSDSC2BA200G4_BTHV7374017P200MGN -> ../../sdf > > lrwxrwxrwx 1 root root 9 Feb 8 00:48 ata-WDC_WD2005FBYZ-01YCBB2_WD-WMC6N0K0SHRT -> ../../sdc > > lrwxrwxrwx 1 root root 9 Feb 8 00:48 ata-WDC_WD2005FBYZ-01YCBB2_WD-WMC6N0K2KNK4 -> ../../sda > > lrwxrwxrwx 1 root root 9 Feb 8 00:48 ata-WDC_WD2005FBYZ-01YCBB2_WD-WMC6N0K5KHNS -> ../../sdb > > lrwxrwxrwx 1 root root 9 Feb 8 00:48 ata-WDC_WD2005FBYZ-01YCBB2_WD-WMC6N0K7212Z -> ../../sde > > lrwxrwxrwx 1 root root 9 Feb 8 00:48 usb-Samsung_Flash_Drive_0352315110002396-0:0 -> ../../sdd > > More de-obfuscation: > - Intel SSD DC S3710 SATA 200GB for caching > - WD Gold SATA 2TB for backing device > > I now also tested with alternatives writethrough and with "hdparm -W 1", > they also crash. > > Perhaps more relevant: fio is started immediately after setup of md > raid and bcache, while md sync speed is set very low: > > echo "1" >/sys/block/md127/md/sync_speed_min > echo "1" >/sys/block/md127/md/sync_speed_max > > > I attached the script I use for producing the crashes, hope this helps. Thanks. Tang Junhui