From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754198AbdHYACJ (ORCPT ); Thu, 24 Aug 2017 20:02:09 -0400 Received: from ipmail01.adl2.internode.on.net ([150.101.137.133]:54216 "EHLO ipmail01.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753456AbdHYACI (ORCPT ); Thu, 24 Aug 2017 20:02:08 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: =?us-ascii?q?A2DkAQAuaJ9Z//yBpztdGgEBAQECAQEBA?= =?us-ascii?q?QgBAQEBhVODLItcj2QGgSqNF4kOghKFQQQCAoUTFgECAQEBAQEBAWsohRkBBSc?= =?us-ascii?q?THCMQCAMOCgklDwUlAyETiiQMrzo6i2EBAQEHAiYggwqDB4VRimcBBKBZlDiSc?= =?us-ascii?q?UiVaCYELYEKMiEIHBWHdS42ihYBAQE?= Date: Fri, 25 Aug 2017 10:01:37 +1000 From: Dave Chinner To: Michal Hocko Cc: Anshuman Khandual , linux-mm@kvack.org, linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, dchinner@redhat.com, bfoster@redhat.com, sandeen@sandeen.net Subject: Re: [PATCH] xfs: Drop setting redundant PF_KSWAPD in kswapd context Message-ID: <20170825000137.GI21024@dastard> References: <20170824104247.8288-1-khandual@linux.vnet.ibm.com> <20170824105635.GA5965@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170824105635.GA5965@dhcp22.suse.cz> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 24, 2017 at 12:56:35PM +0200, Michal Hocko wrote: > On Thu 24-08-17 16:12:47, Anshuman Khandual wrote: > > xfs_btree_split() calls xfs_btree_split_worker() with args.kswapd set > > if current->flags alrady has PF_KSWAPD. Hence we should not again add > > PF_KSWAPD into the current flags inside kswapd context. So drop this > > redundant flag addition. > > I am not familiar with the code but your change seems incorect. The > whole point of args->kswapd is to convey the kswapd context to the > worker which is obviously running in a different context. So this patch > loses the kswapd context. Yup. That's what the code does, and removing the PF_KSWAPD from it will break it. Cheers, Dave. -- Dave Chinner david@fromorbit.com