From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.133]:42888 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387672AbeKFHNZ (ORCPT ); Tue, 6 Nov 2018 02:13:25 -0500 Date: Mon, 5 Nov 2018 13:51:39 -0800 From: Christoph Hellwig Subject: Re: [PATCH] xfs: defer online discard submission to a workqueue Message-ID: <20181105215139.GA3160@infradead.org> References: <20181105181021.8174-1-bfoster@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181105181021.8174-1-bfoster@redhat.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Brian Foster Cc: linux-xfs@vger.kernel.org On Mon, Nov 05, 2018 at 01:10:21PM -0500, Brian Foster wrote: > When online discard is enabled, discards of busy extents are > submitted asynchronously as a bio chain. bio completion and > resulting busy extent cleanup is deferred to a workqueue. Async > discard submission is intended to avoid blocking log forces on a > full discard sequence which can take a noticeable amount of time in > some cases. > > We've had reports of this still producing log force stalls with XFS > on VDO, Please fix this in VDO instead. We should not work around out of tree code making stupid decisions.