From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 82B27EB64DD for ; Thu, 20 Jul 2023 04:48:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229591AbjGTEse (ORCPT ); Thu, 20 Jul 2023 00:48:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229560AbjGTEsc (ORCPT ); Thu, 20 Jul 2023 00:48:32 -0400 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76B191FD2; Wed, 19 Jul 2023 21:48:31 -0700 (PDT) Received: by verein.lst.de (Postfix, from userid 2407) id 17D4667373; Thu, 20 Jul 2023 06:48:28 +0200 (CEST) Date: Thu, 20 Jul 2023 06:48:27 +0200 From: Christoph Hellwig To: Josef Bacik Cc: Christoph Hellwig , Chris Mason , David Sterba , linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: small writeback fixes Message-ID: <20230720044827.GA1689@lst.de> References: <20230713130431.4798-1-hch@lst.de> <20230718171744.GA843162@perftesting> <20230719053901.GA3241@lst.de> <20230719115010.GA15617@lst.de> <20230719214255.GA994357@perftesting> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230719214255.GA994357@perftesting> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Wed, Jul 19, 2023 at 05:42:55PM -0400, Josef Bacik wrote: > More investigation, what's happening is dmsetup suspend is stuck because it's > waiting for outstanding io to finish, so these other IO's are stuck in the > deffered list for the linear mapping. I'm still getting to why the outstanding > IO's aren't going, I'll figure that out in the morning, but seems like this may > not be a btrfs problem. Thanks, I tried to bisect it based on my earlier observation that 6.5-rc2 wasn't affect, but at that point could not reproduce the hang any more. Overall the conditions seems very non-deterministic and might depend on the state and thus latency of the SSD or something like that. Instead of seen a bunch of unmount failures and then busy devices which clear up with another re-run..