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: 12844874 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 472D6C433F5 for ; Tue, 10 May 2022 11:14:35 +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=2Kww1OpVA2YWm8OyoFsE/yIWIS+feAHdyIBPo94Dy6E=; b=zm4pJnNBO3TJsQ PAenplHS/wrku72FVcrAPujnIOM4sDd0l1lGO76s1I6arPelNbljWDcMhBUCo90MrO2OUT4GJcAXk tMp5KFc08uVLuBSC3XP9xmovxm8WzP1g2LW7xV+XXdjM5RT9i9gAaIBogXCaaqErp/1BL2H7jTeP/ mMPAP/yxkJ1Z1Czp08YGAvireol3ortINrXJIJCTY9db9PpoyYpxRF7jKYc1wyQ+DiQEbgvyBk5ER YRk1E94HfXGNgtreUN7dR3vQ1p5NdrVx+BXXmK3AN5nvSyUcpeYEyLKmxmqm7Lp4whQDi+ism08uQ khYguBleJZOKKHScTqRw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1noNo6-001SEG-8H; Tue, 10 May 2022 11:13:34 +0000 Received: from out199-10.us.a.mail.aliyun.com ([47.90.199.10]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1noNnl-001S2k-9v for linux-arm-kernel@lists.infradead.org; Tue, 10 May 2022 11:13:16 +0000 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220510_041313_683697_212149A1 X-CRM114-Status: UNSURE ( 9.19 ) 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 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(-)