From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Herbszt Subject: Re: [PATCH] Separate target visibility from reaped state information Date: Sun, 31 Jan 2016 18:54:55 +0100 Message-ID: <20160131185455.00000ef7@localhost> References: <568FE922.9090004@sandisk.com> <1453251809.2320.56.camel@HansenPartnership.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from mout.gmx.net ([212.227.15.19]:58770 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932825AbcAaRz0 (ORCPT ); Sun, 31 Jan 2016 12:55:26 -0500 In-Reply-To: <1453251809.2320.56.camel@HansenPartnership.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley , "Martin K. Petersen" Cc: Bart Van Assche , Christoph Hellwig , Johannes Thumshirn , Dan Williams , "linux-scsi@vger.kernel.org" , Sebastian Herbszt James Bottomley wrote: > On Tue, 2016-01-19 at 19:30 -0500, Martin K. Petersen wrote: > > > > > > > "Bart" == Bart Van Assche > > > > > > > writes: > > > > Bart> Instead of representing the states "visible in sysfs" and "has > > Bart> been removed from the target list" by a single state variable, > > use > > Bart> two variables to represent this information. > > > > James: Are you happy with the latest iteration of this? Should I > > queue > > it? > > Well, I'm OK with the patch: it's a simple transformation of the > enumerated state to a two bit state. What I can't see is how it fixes > any soft lockup. > > The only change from the current workflow is that the DEL transition > (now the reaped flag) is done before the spin lock is dropped which > would fix a tiny window for two threads both trying to remove the same > target, but there's nothing that could possibly fix an iterative soft > lockup caused by restarting the loop, which is what the changelog says. > > James James, Martin, what's the status of this patch? I still hit the reported soft lockup on 4.5-rc1. Sebastian