Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965287AbcDYVqZ (ORCPT ); Mon, 25 Apr 2016 17:46:25 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:56672 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965020AbcDYVqX (ORCPT ); Mon, 25 Apr 2016 17:46:23 -0400 Date: Mon, 25 Apr 2016 14:46:21 -0700 From: Andrew Morton To: Dan Streetman Cc: Yu Zhao , Seth Jennings , Sergey Senozhatsky , Minchan Kim , Nitin Gupta , Linux-MM , Sergey Senozhatsky , linux-kernel , Dan Streetman Subject: Re: [PATCH] mm/zpool: use workqueue for zpool_destroy Message-Id: <20160425144621.07f246158845fc08815c39dd@linux-foundation.org> In-Reply-To: <1461619210-10057-1-git-send-email-ddstreet@ieee.org> References: <1461619210-10057-1-git-send-email-ddstreet@ieee.org> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 851 Lines: 22 On Mon, 25 Apr 2016 17:20:10 -0400 Dan Streetman wrote: > Add a work_struct to struct zpool, and change zpool_destroy_pool to > defer calling the pool implementation destroy. > > The zsmalloc pool destroy function, which is one of the zpool > implementations, may sleep during destruction of the pool. However > zswap, which uses zpool, may call zpool_destroy_pool from atomic > context. So we need to defer the call to the zpool implementation > to destroy the pool. > > This is essentially the same as Yu Zhao's proposed patch to zsmalloc, > but moved to zpool. OK, but the refrain remains the same: what are the runtime effects of the change? Are real people in real worlds seeing scary kernel warnings? Deadlocks? This info is needed so that I and others can decide which kernel version(s) should be patched. Thanks.