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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 EFBC6C433E2 for ; Wed, 16 Sep 2020 00:42:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA89B20770 for ; Wed, 16 Sep 2020 00:42:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=bytedance-com.20150623.gappssmtp.com header.i=@bytedance-com.20150623.gappssmtp.com header.b="lc0/0lOX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726665AbgIPAmS (ORCPT ); Tue, 15 Sep 2020 20:42:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726591AbgIONC4 (ORCPT ); Tue, 15 Sep 2020 09:02:56 -0400 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 151FDC061352 for ; Tue, 15 Sep 2020 06:02:56 -0700 (PDT) Received: by mail-pf1-x443.google.com with SMTP id c196so1928273pfc.0 for ; Tue, 15 Sep 2020 06:02:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=eNchCXlujHVbLKrDly+nb0OZuzhDeUp4zy0iJXX+zts=; b=lc0/0lOXMXW6CqInlrV1vRTsQtfbMiUBOwP4cPSQ/2UvctoSkPq85BGm4npwx+3wUc VqUklikLospgrLDQ4wlW3z7rPyOBrciyG1K0DugATR9FIHAYeCTZSiXDv5SOiU8HNN4e z2S6v7c0SeINkiwtNed/vqPdtCGDDopnBEbxbRUw/oWYqcgtnq9kg/b1BUUAABcHlhTb rDilY8ZLwf2qRc9VvcjtsCtmKcBoZ5vkzsG7FvnWeB2eqtXZGodOHGHj9GslKqG4bjbz DcbPgKTU/Gucf9acbpdx0Zpf0x9H+UEafA7kwQVLDGAd7Ilj/oVoLIVGpKR30LL2G/7m Bspw== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=eNchCXlujHVbLKrDly+nb0OZuzhDeUp4zy0iJXX+zts=; b=B98Gjz46Xla+LrjLKUdOsuHHtZOEGWdZe0fmR/HIuFf9qWXaH+UPA5RWwH4I0siMau ov0tNtwu5QJvML9h2nnt55rTeqodtp2csqdaeR3hKlE0ergtvWCNWhL813XmyktqWcUQ fnL64NOyZEAU/znIIan7QNEqrwsQ7YnM27hsrRLfx7XMTNA4kLI9k9aeY/EGarP2vgWn GQTPVPdf+LLavGevjVboZ5PSc2zppXGk1Nyil2dN0wnIF2SwaYWdG8cT+WjJYJJlBNEH i2rCmW7qWCOyyat4EApg7Y+cudPBzgpszPJ8fXpMZl7IpPApXWwQ9znWetVKpQBCPH/M Ci4w== X-Gm-Message-State: AOAM533kKwdtRD9igmZ9jzkpdrPAmO2T6+ZvRSeDTLe1oj8iAsFtVp7k gaZdeSI9CbcWJjpfQYHxC2ZNhQ== X-Google-Smtp-Source: ABdhPJwmk58xJFs7bVQwlQ8TOo6QNgpQumZzCogF3iD2x+NuPWVnOo/NDEmSo5qdwcLGuncUFiCQYA== X-Received: by 2002:a62:7ed5:0:b029:13e:d13d:a086 with SMTP id z204-20020a627ed50000b029013ed13da086mr17607925pfc.29.1600174975269; Tue, 15 Sep 2020 06:02:55 -0700 (PDT) Received: from localhost.bytedance.net ([103.136.220.66]) by smtp.gmail.com with ESMTPSA id w185sm14269855pfc.36.2020.09.15.06.02.44 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 15 Sep 2020 06:02:54 -0700 (PDT) From: Muchun Song To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Muchun Song Subject: [RFC PATCH 17/24] mm/hugetlb: Add a BUILD_BUG_ON to check if struct page size is a power of two Date: Tue, 15 Sep 2020 20:59:40 +0800 Message-Id: <20200915125947.26204-18-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20200915125947.26204-1-songmuchun@bytedance.com> References: <20200915125947.26204-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We only can free the unused vmemmap to the buddy system when the size of struct page is a power of two. So add a BUILD_BUG_ON to check the illegal case. Signed-off-by: Muchun Song --- mm/hugetlb.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 7072b849af3d..34706cec21ec 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3817,6 +3817,10 @@ static int __init hugetlb_init(void) { int i; +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP + BUILD_BUG_ON_NOT_POWER_OF_2(sizeof(struct page)); +#endif + if (!hugepages_supported()) { if (hugetlb_max_hstate || default_hstate_max_huge_pages) pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n"); -- 2.20.1