From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B89C6C43144 for ; Fri, 22 Jun 2018 16:28:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A400245CA for ; Fri, 22 Jun 2018 16:28:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A400245CA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934420AbeFVQ2u (ORCPT ); Fri, 22 Jun 2018 12:28:50 -0400 Received: from mail-wr0-f196.google.com ([209.85.128.196]:43167 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934164AbeFVQ2t (ORCPT ); Fri, 22 Jun 2018 12:28:49 -0400 Received: by mail-wr0-f196.google.com with SMTP id d2-v6so7248062wrm.10 for ; Fri, 22 Jun 2018 09:28:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=FW1DIyGep9jzNGj98n5+2iAPwhw+YUsx3qRxJWpnxFg=; b=kIj+f77J3P29sD9e76LEWSSKYrlq7XDpmziVS1vpgOWJmGH/q7k1SV5a1+PczoDy8B aBB7qjE0ZCDuxmgRRfBRQjgPFyXGWTOV6/GVCdBQm0vNh+klgqsO8xUnQO/pnraeVr8E OZvr6Wk2O0hVC/I/BNEaJffMH97jfrUaS9UJhqJuMNWJMEZ+vCoXdmvyWbywOu66Tbdl z02T4GMHCVAJ0S8bHD2+UszU5cSAta7kUwFmA4rZO9ZFB3ivJ1FV32IszlGydrbfE4O2 PvOO8K3XPJ2AOxQ8XmVuMnxv0Q3WTya5KFbHFWfDiKuyyrJx7SHEehY48Zd4bi4ovcv7 Gvwg== X-Gm-Message-State: APt69E1f6Mt97/ygudfwJ213qD3IZrQEH5uwD5d/TyMYMQ72BS1fUAIc ge7285T3YfaE/V9/116YN3I= X-Google-Smtp-Source: AAOMgpfEQogbLwAcE8rKN7lTg7tcr7+54Cg8dHgH6UqYe/HR4itdkQQ26i83aOw7IIF8MpDspn4QYQ== X-Received: by 2002:adf:a0c2:: with SMTP id n2-v6mr2055475wrn.23.1529684928402; Fri, 22 Jun 2018 09:28:48 -0700 (PDT) Received: from tiehlicka.suse.cz (ip-37-188-179-217.eurotel.cz. [37.188.179.217]) by smtp.gmail.com with ESMTPSA id h77-v6sm3520193wmd.9.2018.06.22.09.28.46 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 22 Jun 2018 09:28:47 -0700 (PDT) From: Michal Hocko To: Andrew Morton Cc: JianKang Chen , Mel Gorman , Johannes Weiner , linux-mm@kvack.org, linux-kernel@vger.kernel.org, xieyisheng1@huawei.com, guohanjun@huawei.com, wangkefeng.wang@huawei.com, Michal Hocko Subject: [PATCH] mm: drop VM_BUG_ON from __get_free_pages Date: Fri, 22 Jun 2018 18:28:41 +0200 Message-Id: <20180622162841.25114-1-mhocko@kernel.org> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michal Hocko 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 --- Hi Andrew, previously posted [1] but it fell through cracks. Can we merge it now? [1] http://lkml.kernel.org/r/20171129160446.jluzpv3n6mjc3fwv@dhcp22.suse.cz mm/page_alloc.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 1521100f1e63..5f56f662a52d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4402,18 +4402,14 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid, EXPORT_SYMBOL(__alloc_pages_nodemask); /* - * Common helper functions. + * Common helper functions. Never use with __GFP_HIGHMEM because the returned + * address cannot represent highmem pages. Use alloc_pages and then kmap if + * you need to access high mem. */ unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) { struct page *page; - /* - * __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); if (!page) return 0; -- 2.17.1