From patchwork Tue May 10 11:12:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolin Wang X-Patchwork-Id: 12844870 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id AC41AC433EF for ; Tue, 10 May 2022 11:13:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 367826B0072; Tue, 10 May 2022 07:13:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 315456B0073; Tue, 10 May 2022 07:13:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1DC206B0074; Tue, 10 May 2022 07:13:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 0B9B26B0072 for ; Tue, 10 May 2022 07:13:11 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id CC0AF1820 for ; Tue, 10 May 2022 11:13:10 +0000 (UTC) X-FDA: 79449571740.26.C0B9636 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by imf21.hostedemail.com (Postfix) with ESMTP id 1AEC81C00A7 for ; Tue, 10 May 2022 11:13:01 +0000 (UTC) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R641e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0VCqxQ84_1652181184; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VCqxQ84_1652181184) by smtp.aliyun-inc.com(127.0.0.1); Tue, 10 May 2022 19:13:05 +0800 From: Baolin Wang To: catalin.marinas@arm.com, will@kernel.org, mike.kravetz@oracle.com, akpm@linux-foundation.org Cc: songmuchun@bytedance.com, willy@infradead.org, anshuman.khandual@arm.com, christophe.leroy@csgroup.eu, baolin.wang@linux.alibaba.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 0/2] Implement arm64 specific huge_ptep_get() Date: Tue, 10 May 2022 19:12:51 +0800 Message-Id: X-Mailer: git-send-email 1.8.3.1 Authentication-Results: imf21.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf21.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.130 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 1AEC81C00A7 X-Rspam-User: X-Stat-Signature: kkcrukpisw8c7aprckiore5ngh5k9jia X-HE-Tag: 1652181181-578948 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi, As Mike pointed out [1], the huge_ptep_get() will only return one specific pte value for the CONT-PTE or CONT-PMD size hugetlb on ARM64 system, which will not take into account the subpages' dirty or young bits of a CONT-PTE/PMD size hugetlb page. That will make us miss dirty or young flags of a CONT-PTE/PMD size hugetlb page for those functions that want to check the dirty or young flags of a hugetlb page. For example, the gather_hugetlb_stats() will get inaccurate dirty hugetlb page statistics, and the DAMON for hugetlb monitoring will also get inaccurate access statistics. To fix this issue, this patch set introduces an ARM64 specific huge_ptep_get() implementation, which will take into account any subpages' dirty or young bits. [1] https://lore.kernel.org/linux-mm/85bd80b4-b4fd-0d3f-a2e5-149559f2f387@oracle.com/ Changes from RFC: - Implement arm64 specific huge_ptep_get() instead of introducing a new interface. - Add a new patch to convert huge_ptep_get() in hugetlbpage.c Baolin Wang (2): arm64/hugetlb: Use ptep_get() to get the pte value of a huge page arm64/hugetlb: Implement arm64 specific huge_ptep_get() arch/arm64/include/asm/hugetlb.h | 2 ++ arch/arm64/mm/hugetlbpage.c | 32 ++++++++++++++++++++++++++++---- 2 files changed, 30 insertions(+), 4 deletions(-)