From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Mason Subject: Re: [PATCH v2]Btrfs: pwrite blocked when writing from the mmaped buffer of the same page Date: Thu, 24 Feb 2011 11:00:59 -0500 Message-ID: <1298563230-sup-9619@think> References: <1291887014-18447-1-git-send-email-xin.zhong@intel.com> <201101280354.36884.johannes.hirte@fem.tu-ilmenau.de> <1865303E0DED764181A9D882DEF65FB685DF762B45@shsmsx502.ccr.corp.intel.com> <201102020034.43808.johannes.hirte@fem.tu-ilmenau.de> <1865303E0DED764181A9D882DEF65FB68621CA7167@shsmsx502.ccr.corp.intel.com> <1298028713.11103.13.camel@mainframe> <1865303E0DED764181A9D882DEF65FB686421B24FB@shsmsx502.ccr.corp.intel.com> <1298559118.11224.40.camel@mainframe> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=ISO-8859-1 Cc: =?utf-8?q?Maria_Wikstr=C3=B6m?= , "Zhong, Xin" , Johannes Hirte , "linux-btrfs@vger.kernel.org" To: Mitch Harder Return-path: In-reply-to: List-ID: Excerpts from Mitch Harder's message of 2011-02-24 10:55:15 -0500: > 2011/2/24 Maria Wikstr=C3=B6m : > > m=C3=A5n 2011-02-21 klockan 09:51 +0800 skrev Zhong, Xin: > >> The backtrace in your attachment looks like a known bug of 2.6.37 = which have already been fixed in 2.6.38. I have no idea why latest btrf= s still hang in your environment if there's no debug info... > >> > > > > Haha, yes that's very hard :) > > > > 2.6.38-rc6 and btrfs-unstable behaves the same way. I can close the > > process with ctrl+c and it disappear a few seconds later. There is = no > > CPU usage. Reading works because I can start htop and watch "svn in= fo" > > disappear, but everything writing to btrfs slows down to a crawl. I= t > > takes about 1 minute to log in. So I had to put the logs on an othe= r > > partition using ext3 to get the output from sysrq+t. > > >=20 > I believe I've been experiencing this issue also. However, my proble= m > usually results in a "No space left on device" error rather than a > lock-up or crash. But I've bisected my issue to this patch, and my > "btrfs fi show" and "btrfs fi df" looks similar to others who've > posted to this tread with all my space being allocated, but not used. >=20 Sorry, which patch did you bisect the problem down to? > I've been playing around with ftrace to try to get some information o= n > the issue. Since I'm getting a soft error, I can used a command like > "echo 1 > tracing_on; emerge -1av openmotif; echo 0 > tracing_on" to > end the trace as soon as the build fails. >=20 > The traces are probably too large for the M/L (~275kb compressed), so > I've put them up on my local server in case anybody can find them > useful: >=20 > http://dontpanic.dyndns.org/emerge-openmotif-ftrace.gz >=20 > I'm still only capturing the tail end of the problem, but maybe > someone will find these insightful. >=20 > Let me know if you want me to increase the ftrace buffer size or > insert some trace_printk debugging statements. Thanks, I'll take a look. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html