From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:60319 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752717AbaF0NHJ (ORCPT ); Fri, 27 Jun 2014 09:07:09 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1X0Vrv-0008U7-3e for linux-btrfs@vger.kernel.org; Fri, 27 Jun 2014 15:07:07 +0200 Received: from ip68-231-22-224.ph.ph.cox.net ([68.231.22.224]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 27 Jun 2014 15:07:07 +0200 Received: from 1i5t5.duncan by ip68-231-22-224.ph.ph.cox.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 27 Jun 2014 15:07:07 +0200 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: Blocked tasks on 3.15.1 Date: Fri, 27 Jun 2014 13:06:52 +0000 (UTC) Message-ID: References: <52e3cfababa49919100759860b59aa7c@admin.virtall.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Tomasz Chmielewski posted on Fri, 27 Jun 2014 12:02:43 +0200 as excerpted: >> I've been getting blocked tasks on 3.15.1 generally at times when the >> filesystem is somewhat busy (such as doing a backup via scp/clonezilla >> writing to the disk). > > I've started seeing similar on several servers, after upgrading to 3.15 > or 3.15.1. With 3.16-rc1 it was even crashing for me. > I've rolled back to the latest 3.14.x, and it's still behaving fine. > > I've signalled it before on the list in "btrfs filesystem hang with > 3.15-rc3 when doing rsync" thread. There is a known btrfs lockup bug that was introduced in the commit- window btrfs pull for 3.16, that was fixed by a pull I believe the day before 3.16-rc2. So 3.16-pre to rc2 is known-bad tho it'll work for a few minutes and didn't do any permanent damage that I could see, here. But from 3.16-rc2 on, the 3.16-pre series has been working fine for me. For 3.15, I didn't run the pre-releases as I had another project I was focusing on, but I experienced no problems with 3.15 itself. However, my use-case is multiple independent small btrfs on partitioned SSD, sub-100- GB per btrfs, so I'd be less likely to experience the blocked task issues that others reported, mostly on TB+ size spinning rust. And it /did/ seem to me that the frequency of blocked-task reports were higher for 3.15 than for previous kernel series, tho 3.15 worked fine for me on small btrfs on SSD, the relatively short time I ran it. Hopefully that problem's fixed on 3.16-rc2+, but as of yet there's not enough 3.16-rc2+ reports out there from folks experiencing issues with 3.15 blocked tasks to rightfully say. What CAN be said is that the known 3.16-series commit-window btrfs lockups bug that DID affect me was fixed right before rc2, and I'm running rc2+ just fine, here. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman