From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f43.google.com (mail-qg0-f43.google.com [209.85.192.43]) by kanga.kvack.org (Postfix) with ESMTP id 188936B0255 for ; Wed, 25 Nov 2015 09:59:18 -0500 (EST) Received: by qgec40 with SMTP id c40so33486406qge.2 for ; Wed, 25 Nov 2015 06:59:17 -0800 (PST) Received: from na01-bl2-obe.outbound.protection.outlook.com (mail-bl2on0078.outbound.protection.outlook.com. [65.55.169.78]) by mx.google.com with ESMTPS id g109si21338358qgf.43.2015.11.25.06.59.17 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 25 Nov 2015 06:59:17 -0800 (PST) Subject: Re: [PATCH] Fix a bdi reregistration race, v2 References: <564F9AFF.3050605@sandisk.com> <20151124231331.GA25591@infradead.org> <5654F169.6070000@sandisk.com> <20151125084744.GA16429@infradead.org> From: Bart Van Assche Message-ID: <5655CCC0.9010107@sandisk.com> Date: Wed, 25 Nov 2015 06:59:12 -0800 MIME-Version: 1.0 In-Reply-To: <20151125084744.GA16429@infradead.org> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig Cc: James Bottomley , "Martin K. Petersen" , Jens Axboe , Tejun Heo , Jan Kara , Hannes Reinecke , Aaro Koskinen , "linux-scsi@vger.kernel.org" , linux-mm@kvack.org On 11/25/15 00:47, Christoph Hellwig wrote: > But what I really wanted to ask for is what your reproducer looks like. Hello Christoph, This race is hard to trigger. I can trigger it by repeatedly removing and re-adding SRP SCSI devices. Enabling debug options like SLUB debugging and kmemleak helps. I think that is because these debug options slow down the SCSI device removal code and thereby increase the chance that this race is triggered. Bart. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org