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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 5451316256F0 for ; Mon, 30 Jul 2018 16:29:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1110020870 for ; Mon, 30 Jul 2018 16:29:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1110020870 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=alien8.de 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 S1731749AbeG3SFP (ORCPT ); Mon, 30 Jul 2018 14:05:15 -0400 Received: from mail.skyhub.de ([5.9.137.197]:41502 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726760AbeG3SFO (ORCPT ); Mon, 30 Jul 2018 14:05:14 -0400 X-Virus-Scanned: Nedap ESD1 at mail.skyhub.de Received: from mail.skyhub.de ([127.0.0.1]) by localhost (blast.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id KDLgMYo83hC0; Mon, 30 Jul 2018 18:29:28 +0200 (CEST) Received: from nazgul.tnic (95-42-131-245.ip.btc-net.bg [95.42.131.245]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 534551EC00F4; Mon, 30 Jul 2018 18:29:28 +0200 (CEST) Date: Mon, 30 Jul 2018 18:29:27 +0200 From: Borislav Petkov To: Cannon Matthews Cc: Michal Hocko , Mike Kravetz , Andrew Morton , Matthew Wilcox , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andres Lagar-Cavilla , Salman Qazi , Paul Turner , David Matlack , Peter Feiner , Alain Trinh Subject: Re: [PATCH v2] RFC: clear 1G pages with streaming stores on x86 Message-ID: <20180730162926.GD11890@nazgul.tnic> References: <20180724210923.GA20168@bombadil.infradead.org> <20180725023728.44630-1-cannonmatthews@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180725023728.44630-1-cannonmatthews@google.com> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 24, 2018 at 07:37:28PM -0700, Cannon Matthews wrote: > diff --git a/arch/x86/lib/clear_page_64.S b/arch/x86/lib/clear_page_64.S > index 88acd349911b..81a39804ac72 100644 > --- a/arch/x86/lib/clear_page_64.S > +++ b/arch/x86/lib/clear_page_64.S > @@ -49,3 +49,23 @@ ENTRY(clear_page_erms) > ret > ENDPROC(clear_page_erms) > EXPORT_SYMBOL_GPL(clear_page_erms) > + > +/* > + * Zero memory using non temporal stores, bypassing the cache. > + * Requires an `sfence` (wmb()) afterwards. > + * %rdi - destination. > + * %rsi - page size. Must be 64 bit aligned. > +*/ > +ENTRY(__clear_page_nt) > + leaq (%rdi,%rsi), %rdx > + xorl %eax, %eax > + .p2align 4,,10 > + .p2align 3 > +.L2: > + movnti %rax, (%rdi) > + addq $8, %rdi > + cmpq %rdx, %rdi > + jne .L2 > + ret > +ENDPROC(__clear_page_nt) > +EXPORT_SYMBOL(__clear_page_nt) EXPORT_SYMBOL_GPL like the other functions in that file. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. --