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=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT 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 22425C433E0 for ; Tue, 30 Jun 2020 02:14:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0098D2078A for ; Tue, 30 Jun 2020 02:14:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728343AbgF3COn (ORCPT ); Mon, 29 Jun 2020 22:14:43 -0400 Received: from out30-44.freemail.mail.aliyun.com ([115.124.30.44]:47279 "EHLO out30-44.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725988AbgF3COn (ORCPT ); Mon, 29 Jun 2020 22:14:43 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R881e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04357;MF=richard.weiyang@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0U16sMPl_1593483280; Received: from localhost(mailfrom:richard.weiyang@linux.alibaba.com fp:SMTPD_---0U16sMPl_1593483280) by smtp.aliyun-inc.com(127.0.0.1); Tue, 30 Jun 2020 10:14:40 +0800 From: Wei Yang To: dan.j.williams@intel.com, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Wei Yang Subject: [PATCH] mm/sparse: only sub-section aligned range would be populated Date: Tue, 30 Jun 2020 10:14:36 +0800 Message-Id: <20200630021436.43281-1-richard.weiyang@linux.alibaba.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are two code path which invoke __populate_section_memmap() * sparse_init_nid() * sparse_add_section() For both case, we are sure the memory range is sub-section aligned. * we pass PAGES_PER_SECTION to sparse_init_nid() * we check range by check_pfn_span() before calling sparse_add_section() Also, the counterpart of __populate_section_memmap(), we don't do such calculation and check since the range is checked by check_pfn_span() in __remove_pages(). Clear the calculation and check to keep it simple and comply with its counterpart. Signed-off-by: Wei Yang --- mm/sparse-vmemmap.c | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index 0db7738d76e9..24b01ebae111 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -247,20 +247,8 @@ int __meminit vmemmap_populate_basepages(unsigned long start, struct page * __meminit __populate_section_memmap(unsigned long pfn, unsigned long nr_pages, int nid, struct vmem_altmap *altmap) { - unsigned long start; - unsigned long end; - - /* - * The minimum granularity of memmap extensions is - * PAGES_PER_SUBSECTION as allocations are tracked in the - * 'subsection_map' bitmap of the section. - */ - end = ALIGN(pfn + nr_pages, PAGES_PER_SUBSECTION); - pfn &= PAGE_SUBSECTION_MASK; - nr_pages = end - pfn; - - start = (unsigned long) pfn_to_page(pfn); - end = start + nr_pages * sizeof(struct page); + unsigned long start = (unsigned long) pfn_to_page(pfn); + unsigned long end = start + nr_pages * sizeof(struct page); if (vmemmap_populate(start, end, nid, altmap)) return NULL; -- 2.20.1 (Apple Git-117)