From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f200.google.com (mail-wr0-f200.google.com [209.85.128.200]) by kanga.kvack.org (Postfix) with ESMTP id B45A22808A2 for ; Thu, 9 Mar 2017 03:50:57 -0500 (EST) Received: by mail-wr0-f200.google.com with SMTP id u108so18859536wrb.3 for ; Thu, 09 Mar 2017 00:50:57 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id e63si3500230wma.43.2017.03.09.00.50.56 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 09 Mar 2017 00:50:56 -0800 (PST) Date: Thu, 9 Mar 2017 09:50:55 +0100 From: Michal Hocko Subject: Re: "mm: fix lazyfree BUG_ON check in try_to_unmap_one()" build error Message-ID: <20170309085053.GA11592@dhcp22.suse.cz> References: <20170309042908.GA26702@jagdpanzerIV.localdomain> <20170309060226.GB854@bbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170309060226.GB854@bbox> Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Sergey Senozhatsky , Andrew Morton , Johannes Weiner , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Thu 09-03-17 15:02:26, Minchan Kim wrote: [...] > >From 38b10e560d066c2cef8f9d028e14008cefdaa3e0 Mon Sep 17 00:00:00 2001 > From: Minchan Kim > Date: Thu, 9 Mar 2017 14:58:23 +0900 > Subject: [PATCH] mm: do not use VM_WARN_ON_ONCE as if condition > > Sergey reported VM_WARN_ON_ONCE returns void with !CONFIG_DEBUG_VM > so we cannot use it as if's condition unlike WARN_ON. I would swear I've seen WARN_ON_ONCE there when looking at the previous patch! Btw. could have simply s@VM_@@ > This patch fixes it. > > Signed-off-by: Minchan Kim Acked-by: Michal Hocko > --- > mm/rmap.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/mm/rmap.c b/mm/rmap.c > index 1d82057144ba..7d24bb93445b 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -1413,12 +1413,11 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, > * Store the swap location in the pte. > * See handle_pte_fault() ... > */ > - if (VM_WARN_ON_ONCE(PageSwapBacked(page) != > - PageSwapCache(page))) { > + if (unlikely(PageSwapBacked(page) != PageSwapCache(page))) { > + WARN_ON_ONCE(1); > ret = SWAP_FAIL; > page_vma_mapped_walk_done(&pvmw); > break; > - > } > > /* MADV_FREE page check */ > -- > 2.7.4 -- Michal Hocko SUSE Labs -- 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