From patchwork Thu Oct 11 22:13:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Duyck X-Patchwork-Id: 982760 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=sparclinux-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42WQLw6gTyz9s3Z for ; Fri, 12 Oct 2018 09:17:28 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726887AbeJLFqM (ORCPT ); Fri, 12 Oct 2018 01:46:12 -0400 Received: from mga12.intel.com ([192.55.52.136]:35657 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726072AbeJLFqM (ORCPT ); Fri, 12 Oct 2018 01:46:12 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Oct 2018 15:16:55 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,370,1534834800"; d="scan'208";a="80765698" Received: from ahduyck-mobl.amr.corp.intel.com (HELO localhost.localdomain) ([10.7.198.157]) by orsmga008.jf.intel.com with ESMTP; 11 Oct 2018 15:13:34 -0700 Subject: [mm PATCH v2 1/6] mm: Use mm_zero_struct_page from SPARC on all 64b architectures From: Alexander Duyck To: linux-mm@kvack.org, akpm@linux-foundation.org Cc: pavel.tatashin@microsoft.com, mhocko@suse.com, dave.jiang@intel.com, alexander.h.duyck@linux.intel.com, linux-kernel@vger.kernel.org, willy@infradead.org, davem@davemloft.net, yi.z.zhang@linux.intel.com, khalid.aziz@oracle.com, rppt@linux.vnet.ibm.com, vbabka@suse.cz, sparclinux@vger.kernel.org, dan.j.williams@intel.com, ldufour@linux.vnet.ibm.com, mgorman@techsingularity.net, mingo@kernel.org, kirill.shutemov@linux.intel.com Date: Thu, 11 Oct 2018 15:13:34 -0700 Message-ID: <20181011221334.1925.31961.stgit@localhost.localdomain> In-Reply-To: <20181011221237.1925.85591.stgit@localhost.localdomain> References: <20181011221237.1925.85591.stgit@localhost.localdomain> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: sparclinux-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: sparclinux@vger.kernel.org This change makes it so that we use the same approach that was already in use on Sparc on all the archtectures that support a 64b long. This is mostly motivated by the fact that 8 to 10 store/move instructions are likely always going to be faster than having to call into a function that is not specialized for handling page init. An added advantage to doing it this way is that the compiler can get away with combining writes in the __init_single_page call. As a result the memset call will be reduced to only about 4 write operations, or at least that is what I am seeing with GCC 6.2 as the flags, LRU poitners, and count/mapcount seem to be cancelling out at least 4 of the 8 assignments on my system. One change I had to make to the function was to reduce the minimum page size to 56 to support some powerpc64 configurations. Signed-off-by: Alexander Duyck --- arch/sparc/include/asm/pgtable_64.h | 30 ------------------------------ include/linux/mm.h | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+), 30 deletions(-) diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h index 1393a8ac596b..22500c3be7a9 100644 --- a/arch/sparc/include/asm/pgtable_64.h +++ b/arch/sparc/include/asm/pgtable_64.h @@ -231,36 +231,6 @@ 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 - */ -#define mm_zero_struct_page(pp) do { \ - unsigned long *_pp = (void *)(pp); \ - \ - /* Check that struct page is either 64, 72, or 80 bytes */ \ - BUILD_BUG_ON(sizeof(struct page) & 7); \ - BUILD_BUG_ON(sizeof(struct page) < 64); \ - BUILD_BUG_ON(sizeof(struct page) > 80); \ - \ - switch (sizeof(struct page)) { \ - case 80: \ - _pp[9] = 0; /* fallthrough */ \ - case 72: \ - _pp[8] = 0; /* fallthrough */ \ - default: \ - _pp[7] = 0; \ - _pp[6] = 0; \ - _pp[5] = 0; \ - _pp[4] = 0; \ - _pp[3] = 0; \ - _pp[2] = 0; \ - _pp[1] = 0; \ - _pp[0] = 0; \ - } \ -} 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, diff --git a/include/linux/mm.h b/include/linux/mm.h index 273d4dbd3883..dee407998366 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -102,8 +102,42 @@ static inline void set_max_mapnr(unsigned long limit) { } * zeroing by defining this macro in . */ #ifndef mm_zero_struct_page +#if BITS_PER_LONG == 64 +/* This function 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 move/store instructions + */ +#define mm_zero_struct_page(pp) __mm_zero_struct_page(pp) +static inline void __mm_zero_struct_page(struct page *page) +{ + unsigned long *_pp = (void *)page; + + /* Check that struct page is either 56, 64, 72, or 80 bytes */ + BUILD_BUG_ON(sizeof(struct page) & 7); + BUILD_BUG_ON(sizeof(struct page) < 56); + BUILD_BUG_ON(sizeof(struct page) > 80); + + switch (sizeof(struct page)) { + case 80: + _pp[9] = 0; /* fallthrough */ + case 72: + _pp[8] = 0; /* fallthrough */ + default: + _pp[7] = 0; /* fallthrough */ + case 56: + _pp[6] = 0; + _pp[5] = 0; + _pp[4] = 0; + _pp[3] = 0; + _pp[2] = 0; + _pp[1] = 0; + _pp[0] = 0; + } +} +#else #define mm_zero_struct_page(pp) ((void)memset((pp), 0, sizeof(struct page))) #endif +#endif /* * Default maximum number of active map areas, this limits the number of vmas