From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kent Overstreet Subject: Re: [bcachefs] BUG: soft lockup - CPU#0 stuck for 22s! [bch_copygc_read:5328] Date: Mon, 5 Sep 2016 18:24:07 -0800 Message-ID: <20160906022407.vukmxltjiyq3hn5s@kmo-pixel> References: <5e794b2230e3af7ec0a06eaceaf7a6fc@mejor.pl> <20160904001729.r3qjqpin62i6d4so@kmo-pixel> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Received: from mail-pf0-f182.google.com ([209.85.192.182]:35039 "EHLO mail-pf0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752652AbcIFCYL (ORCPT ); Mon, 5 Sep 2016 22:24:11 -0400 Received: by mail-pf0-f182.google.com with SMTP id w87so11030015pfk.2 for ; Mon, 05 Sep 2016 19:24:11 -0700 (PDT) Content-Disposition: inline In-Reply-To: Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Marcin Cc: linux-bcache@vger.kernel.org On Sun, Sep 04, 2016 at 08:21:17PM +0200, Marcin wrote: > W dniu 2016-09-04 02:17, Kent Overstreet napisał(a): > > Hi! > > > On Sat, Sep 03, 2016 at 11:29:49PM +0200, Marcin wrote: > > > Hi! > > > Kernel at commit c820493652e830dc050e1418301e1bdec5691a1e > > > > > > I createt to devices, fast has size > > > # blockdev --getsz /dev/sde1 > > > 20971520 > > > and slower device: > > > # blockdev --getsz /dev/sdd1 > > > 2930209551 > > > > > > I was copying files from one disk to bcache, after some time I got: > > > BUG: soft lockup - CPU#0 stuck for 22s! [bch_copygc_read:5328] > > > > Thanks for the report - can you run addr2line with your vmlinux file, > > and the > > RIP? > > > > addr2line -i -e vmlinux ffffffffc028795b > > It returned: > ??:0 > > Probably due to I'm using bcache as module. > > As I mentioned before I wasn't sure which branch I used to test. In case I didn't mention before - bcache-dev. This bug in the bcache-encryption branch is a bit disconcerting though since my tests never hit it, but don't worry about it - I'll chase it down. > Please look at line with "bucket size": > bucket_size: 768 > If bucket size is higher than (probably) 512 then I can't mount simple > (without tiering) bcachefs filesystem. If I use such big device in tiered > bcachefs I'm expieriencing random problems with stability of box. > I think that bug in mail's subject is only random symptom of problem when > device is formated with bucket size >512. > What is going inside kernel in this case, is overwittem memory of other > processes? Whoops - that one is a bug in bcache-tools, non power of two bucket sizes aren't supported (might be someday, but aren't currently). I just pushed a fix for that to bcache-tools.