From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Wheeler Subject: Re: 3.17-rc6: bcache_gc: BUG: soft lockup - CPU#2 stuck for 23s! Date: Mon, 24 Nov 2014 10:52:40 -0800 (PST) Message-ID: References: <20141101204447.GB22219@kmo-pixel> <546FC2B4.5020201@message-id.invalid.com> <1416615728.4084.325.camel@geekdesk.ewheeler.net> <5470858B.9090900@message-id.googlemail.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Return-path: Received: from homie.mail.dreamhost.com ([208.97.132.208]:34399 "EHLO homiemail-a99.g.dreamhost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753652AbaKXSwm (ORCPT ); Mon, 24 Nov 2014 13:52:42 -0500 In-Reply-To: <5470858B.9090900@message-id.googlemail.com> Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Stefan Seyfried Cc: Kent Overstreet , "linux-bcache@vger.kernel.org" , Ross Anderson , Stefan Priebe >>> Before the patch goes upstream I need it tested so I know if it fixes >>> the actual issue or not. >> >> We have been using the rcu_sched patch and the cond_resched patch together >> (both attached) since November 3rd on 3.17.2 without any bcache >> backtraces. bcache is running in writeback mode. The server is >> predominantly write-only with relatively few reads. > > Is the rcu_sched patch supposed to help the same or a totally different > problem? Means: should I also apply it, rebuild the module and reboot > (resetting the test time to zero :-) The second backtrace mentioned on this link is the issue that I believe is fixed with the rcu_sched patch: https://www.mail-archive.com/linux-bcache@vger.kernel.org/msg02623.html The error starts with a message like "INFO: rcu_sched self-detected stall on CPU" -Eric > I had the "deadly" soft lockup once per week since updating to > 3.16/3.17, so I can only tell if it might help in two weeks earliest. > >> To sum up, the attached two patches (plus the for-jens pull) have fixed all >> of our bcache problems since 3.14.y. These patches on 3.17.2 seem quite stable. > > That's good to hear :-) > > Best regards, > > Stefan > -- > Stefan Seyfried > Linux Consultant & Developer -- GPG Key: 0x731B665B > > B1 Systems GmbH > Osterfeldstra?e 7 / 85088 Vohburg / http://www.b1-systems.de > GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt,HRB 3537 > -- > To unsubscribe from this list: send the line "unsubscribe linux-bcache" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >