From patchwork Thu Aug 3 21:23:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Tatashin X-Patchwork-Id: 9879861 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4A436603FB for ; Thu, 3 Aug 2017 21:28:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4F6C428976 for ; Thu, 3 Aug 2017 21:28:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 43C4328915; Thu, 3 Aug 2017 21:28:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.4 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_NONE,RCVD_IN_SORBS_SPAM,UNPARSEABLE_RELAY autolearn=no version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A106E2896D for ; Thu, 3 Aug 2017 21:28:26 +0000 (UTC) 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:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Pgjg/7U1X0jPFMCTOHRXPntughHAG8VIX2drKLJolP4=; b=pCcGKiyXG9Iu4s lP3nZ7pUVCycKF5v5ZgS9409EIE9zUMbiGdF1DSwzd/vEmaIn7J0TqVwKFDtGLuL35BM4w126MbN0 Z7V0elVcOL/YKDsnB4VFFoDLL0E2kUsKE26oCB44dGeMtIzEqwN/02ELgnfprxY8GoV4A01QLXFBk ExsfTmKmxLtWEWXAzS4+v4ML5GHOEvkrq4cMqPJ6+vcR/gk0zQ+wme7i82Ts1HQxq2BC5er0vvgxy WVCwMkvoJACd58AYopo5dRF7ApBr7DITs+zZYkxisGElXZujffO8P/+b4iveyrY7jTNm7QZy4qw7W yUPhM5IQ6vCocqIzVEDg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1ddNf1-0007n1-Vj; Thu, 03 Aug 2017 21:28:03 +0000 Received: from merlin.infradead.org ([2001:8b0:10b:1231::1]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1ddNcY-0005SC-6V for linux-arm-kernel@bombadil.infradead.org; Thu, 03 Aug 2017 21:25:30 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=References:In-Reply-To:Message-Id:Date: Subject:To:From:Sender:Reply-To:Cc:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=4r9U9oR2V+5erwGz8bPnkMLa2iqKwujVJO97Vh4chFw=; b=N9Z+PKviDHF65P1+54K9pBrIQ 2Sdaj+wOR64Nf1sJYpvZn22dfWyHj6CuDyTPvGWD8Y0wzz+EzTVNBY35ooiE6ZSPFtExbwS6ZXGCM xsB+z8IOoLvi1Rq91Zg2iKvB5GGMnx7RakKRiQHR+GW8VKlnJcM43JHGQvKNvHcDvrBaY0+YlzPBE /5RZxsZ/4+Qnu40GXOzDKXG6STMHSXajrp8Tm7R1ZzWAI2Iq/Mi8wX8FCUgb2HRWk3xHz/aW9DGcw wil+U/ufOTmz5akitzoebk9lfg4BkkwAbqAxgo3btu2L58R0v64ulKmIjHiqnugfq0xwFsBDFaqwy H/vavhdrA==; Received: from aserp1040.oracle.com ([141.146.126.69]) by merlin.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1ddNcU-0007SC-JP for linux-arm-kernel@lists.infradead.org; Thu, 03 Aug 2017 21:25:28 +0000 Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id v73LOBWs002473 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 3 Aug 2017 21:24:11 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id v73LOAiE031444 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 3 Aug 2017 21:24:11 GMT Received: from abhmp0004.oracle.com (abhmp0004.oracle.com [141.146.116.10]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id v73LOA73010449; Thu, 3 Aug 2017 21:24:10 GMT Received: from ca-ldom-ol-build-1.us.oracle.com (/10.129.68.23) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 03 Aug 2017 14:24:10 -0700 From: Pavel Tatashin To: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, kasan-dev@googlegroups.com, borntraeger@de.ibm.com, heiko.carstens@de.ibm.com, davem@davemloft.net, willy@infradead.org, mhocko@kernel.org Subject: [v5 09/15] sparc64: optimized struct page zeroing Date: Thu, 3 Aug 2017 17:23:47 -0400 Message-Id: <1501795433-982645-10-git-send-email-pasha.tatashin@oracle.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1501795433-982645-1-git-send-email-pasha.tatashin@oracle.com> References: <1501795433-982645-1-git-send-email-pasha.tatashin@oracle.com> X-Source-IP: aserv0022.oracle.com [141.146.126.234] X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Add an optimized mm_zero_struct_page(), so struct page's are zeroed without calling memset(). We do eight regular stores, thus avoid cost of membar. Signed-off-by: Pavel Tatashin Reviewed-by: Steven Sistare Reviewed-by: Daniel Jordan Reviewed-by: Bob Picco --- arch/sparc/include/asm/pgtable_64.h | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h index 6fbd931f0570..be47537e84c5 100644 --- a/arch/sparc/include/asm/pgtable_64.h +++ b/arch/sparc/include/asm/pgtable_64.h @@ -230,6 +230,38 @@ extern unsigned long _PAGE_ALL_SZ_BITS; extern struct page *mem_map_zero; #define ZERO_PAGE(vaddr) (mem_map_zero) +/* This macro must be updated when the size of struct page grows above 80 + * or reduces below 64. + * The idea that compiler optimizes out switch() statement, and only + * leaves clrx instructions or memset() call. + */ +#define mm_zero_struct_page(pp) do { \ + unsigned long *_pp = (void *)(pp); \ + \ + /* Check that struct page is 8-byte aligned */ \ + BUILD_BUG_ON(sizeof(struct page) & 7); \ + \ + switch (sizeof(struct page)) { \ + case 80: \ + _pp[9] = 0; /* fallthrough */ \ + case 72: \ + _pp[8] = 0; /* fallthrough */ \ + case 64: \ + _pp[7] = 0; \ + _pp[6] = 0; \ + _pp[5] = 0; \ + _pp[4] = 0; \ + _pp[3] = 0; \ + _pp[2] = 0; \ + _pp[1] = 0; \ + _pp[0] = 0; \ + break; /* no fallthrough */ \ + default: \ + pr_warn_once("suboptimal mm_zero_struct_page"); \ + memset(_pp, 0, sizeof(struct page)); \ + } \ +} while (0) + /* PFNs are real physical page numbers. However, mem_map only begins to record * per-page information starting at pfn_base. This is to handle systems where * the first physical page in the machine is at some huge physical address,