From patchwork Fri May 13 03:37:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolin Wang X-Patchwork-Id: 12848341 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EB814C433F5 for ; Fri, 13 May 2022 03:39:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date:Subject:Cc:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=mQhHflbGFBmpBKYvH2HeUJ5opbkD9CwQKiHziTtSlWc=; b=gKR8Jsy0dVUKKb sIhMPabvWZNB13ICWI5oXlojXndDDNPj/wZvbehEGHSEsb10HVdautT/1OkFIX0DJ/dwbeGTOrB0Z kpIj8/23sXTWleA03cAeO6YEYQWxcaOGlbpJ3TFRaUpaEcaUrJqSaRNjpxhG4VkYqRUhogiNs0nzT 6El+SJl56R0uMFjeXP7CSOnRib0FrciifuAK4PNPMFjrkoWuvaPKuv4s+lWS1P34jQV/VDLhk+nHt ydxQkxajqzREJP4cgh9ZVnYt+zpmyjxqXVrwJY4oF4KuNrEg8mevL0GCSybRrh5D6TRXZFmXY6Rvx R45dMd0FneJRKNzAz4aQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1npM81-00EMnF-3L; Fri, 13 May 2022 03:38:09 +0000 Received: from out30-54.freemail.mail.aliyun.com ([115.124.30.54]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1npM7m-00EMfz-EP for linux-arm-kernel@lists.infradead.org; Fri, 13 May 2022 03:37:58 +0000 X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R991e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04400; MF=baolin.wang@linux.alibaba.com; NM=1; PH=DS; RN=12; SR=0; TI=SMTPD_---0VD1NsHJ_1652413066; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VD1NsHJ_1652413066) by smtp.aliyun-inc.com(127.0.0.1); Fri, 13 May 2022 11:37:47 +0800 From: Baolin Wang To: catalin.marinas@arm.com, will@kernel.org Cc: mike.kravetz@oracle.com, akpm@linux-foundation.org, 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 v2 0/2] Implement arm64 specific huge_ptep_get() Date: Fri, 13 May 2022 11:37:33 +0800 Message-Id: X-Mailer: git-send-email 1.8.3.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220512_203754_743512_834ACCFC X-CRM114-Status: UNSURE ( 9.81 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 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+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 v1: - Rebase on next-20220512. - Update commit message suggested by Muchun. - Add reviewed tag from Muchun. 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(-)