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=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 39714C28CBC for ; Wed, 6 May 2020 07:43:27 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 077D0206E6 for ; Wed, 6 May 2020 07:43:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="jPckZ87p"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="QUUm8BzZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 077D0206E6 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-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=xJqdUPESCMNA44VJYdw4oSquzwo27chFEXSVEESntow=; b=jPckZ87pjO9bat Iow/JKXC3cTEMMAA0bQteuwHLzTqenzgkUhzTW5uFVlmWtOubEntZt2cutXzBydt4caZE0b1dc/FQ 2m23QxfJOyF1unGLF7WXxCQV1pTqk1nWi9hfABmsgZ4OekarOgXdpZYFurx4sP+hWfLtLuKHN4XlA jH9hTAftRfZTnlHBlYetLeXspz24NLNCp0q50e0/cJZ9v1Kbsn7C2pkXnWoEx5OoNYxaovLFTIkj2 /vtOpt1iLkhmk+Krwo6aQqAsAQw5wROs4ZZzfaZeopuXXNP76ttuFebPNqqRURF12jmufGyv+X3HJ tAOXyXsU2rTx+yxTgZqQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWEiD-0008Fd-Tv; Wed, 06 May 2020 07:43:25 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWEiB-0008Eq-5m for linux-arm-kernel@lists.infradead.org; Wed, 06 May 2020 07:43:24 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1F5D2206E6; Wed, 6 May 2020 07:43:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588751000; bh=CNBwwDwBOdMK1xYnzJC73BfdILtwbAZgrZjht4vqeyc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QUUm8BzZ8znSKBEEsbsVuGQDziUF1EF3dxO8+Wevy2T47Isn6Mbj360Qi8dfDWRM6 fC4aJjGy4P7u43fwidS4zRE7/mmwnuYl1NTJYv7o/rTJqRtli2t/D66lUvn+IkgD+N dqEi3vJpYxPZOSFMOjzlXG1EF17kaCVBRkm2E5zM= Date: Wed, 6 May 2020 08:43:16 +0100 From: Will Deacon To: Anshuman Khandual Subject: Re: [PATCH V2 1/3] arm64/mm: Drop __HAVE_ARCH_HUGE_PTEP_GET Message-ID: <20200506074315.GD7021@willie-the-truck> References: <1588745534-24418-1-git-send-email-anshuman.khandual@arm.com> <1588745534-24418-2-git-send-email-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1588745534-24418-2-git-send-email-anshuman.khandual@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200506_004323_233113_BBA254AA X-CRM114-Status: GOOD ( 15.42 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-mm@kvack.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Catalin Marinas Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, May 06, 2020 at 11:42:12AM +0530, Anshuman Khandual wrote: > Platform specific huge_ptep_get() is required only when fetching the huge > PTE involves more than just dereferencing the page table pointer. This is > not the case on arm64 platform. Hence huge_ptep_pte() can be dropped along > with it's __HAVE_ARCH_HUGE_PTEP_GET subscription. > > Cc: Catalin Marinas > Cc: Will Deacon > Cc: Andrew Morton > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Anshuman Khandual > --- > arch/arm64/include/asm/hugetlb.h | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h > index 2eb6c234d594..b88878ddc88b 100644 > --- a/arch/arm64/include/asm/hugetlb.h > +++ b/arch/arm64/include/asm/hugetlb.h > @@ -17,12 +17,6 @@ > extern bool arch_hugetlb_migration_supported(struct hstate *h); > #endif > > -#define __HAVE_ARCH_HUGE_PTEP_GET > -static inline pte_t huge_ptep_get(pte_t *ptep) > -{ > - return READ_ONCE(*ptep); > -} Hmm, I'm nervous about dropping the READ_ONCE() here. We added them after running into page-table issues with THP [1] and it's really important to use them consistently to avoid hitting that again. If the generic code used READ_ONCE(), I'd be happy to switch to it. Will [1] https://lore.kernel.org/lkml/1506527369-19535-1-git-send-email-will.deacon@arm.com/ _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel