From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f71.google.com (mail-pl0-f71.google.com [209.85.160.71]) by kanga.kvack.org (Postfix) with ESMTP id 1C0C36B0003 for ; Fri, 6 Apr 2018 06:02:44 -0400 (EDT) Received: by mail-pl0-f71.google.com with SMTP id f4-v6so528423plm.12 for ; Fri, 06 Apr 2018 03:02:44 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id u10si6922762pgb.669.2018.04.06.03.02.42 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 06 Apr 2018 03:02:42 -0700 (PDT) Date: Fri, 6 Apr 2018 12:02:36 +0200 From: Michal Hocko Subject: Re: [PATCH resend] mm/page_alloc: fix comment is __get_free_pages Message-ID: <20180406100236.GK8286@dhcp22.suse.cz> References: <1511780964-64864-1-git-send-email-chenjiankang1@huawei.com> <20171127113341.ldx32qvexqe2224d@dhcp22.suse.cz> <20171129160446.jluzpv3n6mjc3fwv@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171129160446.jluzpv3n6mjc3fwv@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: JianKang Chen , mgorman@techsingularity.net, hannes@cmpxchg.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, xieyisheng1@huawei.com, guohanjun@huawei.com, wangkefeng.wang@huawei.com On Wed 29-11-17 17:04:46, Michal Hocko wrote: [...] > From 000bb422fe07adbfa8cd8ed953b18f48647a45d6 Mon Sep 17 00:00:00 2001 > From: Michal Hocko > Date: Wed, 29 Nov 2017 17:02:33 +0100 > Subject: [PATCH] mm: drop VM_BUG_ON from __get_free_pages > > There is no real reason to blow up just because the caller doesn't know > that __get_free_pages cannot return highmem pages. Simply fix that up > silently. Even if we have some confused users such a fixup will not be > harmful. > > Signed-off-by: Michal Hocko Andrew, have we reached any conclusion for this? Should I repost or drop it on the floor? > --- > mm/page_alloc.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 0d518e9b2ee8..3dd960ea8c13 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -4284,9 +4284,7 @@ unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) > * __get_free_pages() returns a virtual address, which cannot represent > * a highmem page > */ > - VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); > - > - page = alloc_pages(gfp_mask, order); > + page = alloc_pages(gfp_mask & ~__GFP_HIGHMEM, order); > if (!page) > return 0; > return (unsigned long) page_address(page); > -- > 2.15.0 > > -- > Michal Hocko > SUSE Labs -- Michal Hocko SUSE Labs