From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935006AbcLPNA2 (ORCPT ); Fri, 16 Dec 2016 08:00:28 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:11491 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934667AbcLPM7N (ORCPT ); Fri, 16 Dec 2016 07:59:13 -0500 Message-ID: <5853E47E.3040100@huawei.com> Date: Fri, 16 Dec 2016 20:56:30 +0800 From: zhong jiang User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Will Deacon CC: , , , , , , , , , Subject: Re: [RESEND PATCH 2/2] arm64: make WANT_HUGE_PMD_SHARE depends on HUGETLB_PAGE References: <1481725151-20549-1-git-send-email-zhongjiang@huawei.com> <1481725151-20549-3-git-send-email-zhongjiang@huawei.com> <5853AF6D.20305@huawei.com> <20161216123512.GF13191@arm.com> In-Reply-To: <20161216123512.GF13191@arm.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.29.68] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016/12/16 20:35, Will Deacon wrote: > On Fri, Dec 16, 2016 at 05:10:05PM +0800, zhong jiang wrote: >> On 2016/12/14 22:19, zhongjiang wrote: >>> From: zhong jiang >>> >>> when HUGETLB_PAGE is disable, WANT_HUGE_PMD_SHARE contains the >>> fuctions should not be use. therefore, we add the dependency. >>> >>> Signed-off-by: zhong jiang >>> --- >>> arch/arm64/Kconfig | 1 + >>> 1 file changed, 1 insertion(+) >>> >>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >>> index 969ef88..694ca73 100644 >>> --- a/arch/arm64/Kconfig >>> +++ b/arch/arm64/Kconfig >>> @@ -640,6 +640,7 @@ config SYS_SUPPORTS_HUGETLBFS >>> >>> config ARCH_WANT_HUGE_PMD_SHARE >>> def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) >>> + depends on HUGETLB_PAGE >>> >>> config ARCH_HAS_CACHE_LINE_SIZE >>> def_bool y >> Hi, >> I still think it is a issue. Perhaps above changelog is unclear. Further explain is as follows. >> when hugetlb_pages is disable and arch_want_huge_pmd_share is enable, we maybe call >> huge_pmd_sahre in hugetlbpage.c, but the function actually is not definition as it is not >> exported. is it right ?? > The only users of ARCH_WANT_HUGE_PMD_SHARE on arm64 are: > > arch/arm64/mm/hugetlbpage.c: if (IS_ENABLED(CONFIG_ARCH_WANT_HUGE_PMD_SHARE) && yes > mm/hugetlb.c:#ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE > mm/hugetlb.c:#else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ > mm/hugetlb.c:#endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ > > and neither of those files are compiled if !HUGETLB_PAGE. Indeed, but The only users maybe use it if !HUGETLB_PAGE. because include/linux/hugetlb.h can not export the reference if !HUGETLB_PAGE. IOW, the function is not definition. is it right ? or I miss the key point. > Are you actually seeing a problem here? I review the code and find the issue. Thanks zhongjiang > Will > > . >