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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 28A0FFC5918 for ; Thu, 26 Feb 2026 09:27:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4C4EA6B0089; Thu, 26 Feb 2026 04:27:26 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4965B6B008A; Thu, 26 Feb 2026 04:27:26 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3A2266B008C; Thu, 26 Feb 2026 04:27:26 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 26BAC6B0089 for ; Thu, 26 Feb 2026 04:27:26 -0500 (EST) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id BE894140A9D for ; Thu, 26 Feb 2026 09:27:25 +0000 (UTC) X-FDA: 84486079650.20.C6C36B1 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) by imf19.hostedemail.com (Postfix) with ESMTP id A03081A0002 for ; Thu, 26 Feb 2026 09:27:23 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=linux.alibaba.com header.s=default header.b="t7H/RwvO"; spf=pass (imf19.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.132 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=linux.alibaba.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1772098044; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=5Z7J2/ULNSA00ESGJkV5zPKGTqAvtL1rE4wzbzIL92k=; b=eCOdp91TOY90xr14P/6ybADomXzGbDMFu1Yj5oZ7fPqul2HANhFbBTEqNKEoFCMN3iHOWq GMZpn2il7iaBUjLxFUpBq3FVn3I68/junJJg0HZMOnAEPBZVZk7QiIt3wxi3tIh7F4F9vJ 36nKPIG9yYTrCK0A/dHUtW+6pCx5m9g= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1772098044; a=rsa-sha256; cv=none; b=KeJCz/oVbIC8Sj8hsk8XTwFKCFr+uSSTeu4gD1EZrBVPP9rT97EQQARj35MV0DqMIuDR6s V1rbZdyPWiCEIV+00R0gqE7oqxVlTc/Yvg3iKMjLD2vXxY3ZZWnO5rGYyS2lWqArihYXmh iv62JGulEsvcziVXWExvyJTgmn1m0+o= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=linux.alibaba.com header.s=default header.b="t7H/RwvO"; spf=pass (imf19.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.132 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=linux.alibaba.com DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1772098039; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=5Z7J2/ULNSA00ESGJkV5zPKGTqAvtL1rE4wzbzIL92k=; b=t7H/RwvOxr1w+kYVWoXmXIYcgN6QKyrhhd2dNIE58KFFbwlKxL01bV38M1a2wDJvovmGc5il6htMtukPT6+/sxQofloadCnPpWhraOuh+z41j1qK8Dv6CNJa+rqAkNcHSRHy2ecVUmJdPFm9fMEZk5b4Ftvws9R9kqxpNSfn1pM= Received: from 30.74.144.118(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0WzqngAX_1772098037 cluster:ay36) by smtp.aliyun-inc.com; Thu, 26 Feb 2026 17:27:18 +0800 Message-ID: <08a22ed6-3165-41a5-8d46-aaa09402a0f9@linux.alibaba.com> Date: Thu, 26 Feb 2026 17:27:17 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 4/5] mm: support batched checking of the young flag for MGLRU To: "David Hildenbrand (Arm)" , akpm@linux-foundation.org Cc: catalin.marinas@arm.com, will@kernel.org, lorenzo.stoakes@oracle.com, ryan.roberts@arm.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, riel@surriel.com, harry.yoo@oracle.com, jannh@google.com, willy@infradead.org, baohua@kernel.org, dev.jain@arm.com, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, hannes@cmpxchg.org, zhengqi.arch@bytedance.com, shakeel.butt@linux.dev, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <84d2426c63c1eafeaa0cfbad7c5cc11e9c11b980.1771897150.git.baolin.wang@linux.alibaba.com> <2e7a1e24-3616-4b79-b943-b5f7efde2d31@kernel.org> <0871edb9-08a2-46a0-ade6-af842a12e0d3@linux.alibaba.com> <2599bc1e-1f8e-46bc-afea-4cb8f657545b@kernel.org> From: Baolin Wang In-Reply-To: <2599bc1e-1f8e-46bc-afea-4cb8f657545b@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: A03081A0002 X-Stat-Signature: boqsgqqnawnxucyoip7tuk7on9sbumkf X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1772098043-78707 X-HE-Meta: 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 o/FyC4NP qUS0tMIMIFnO695cKykkva3oc56jETl/YdabOW2SB9285Nrn1xePqm23o9QmLlPjPCkPx4jgy8KNPwbhsfnFYuykA6XhqwP42qw5nTHC/8vXGJv0kchkVsuAcBTavXjbLWMM/A1H9ZMEEjgwFaalgOiC2MuJObRkItIShHdv9gCyzkr2UPBdK+21kVQSt5gSbcye/deaQX5+9EWyFXss+R+UafvvZK5WMSmQlL6BIa6MnwJJt75+zeV3bVAvkht9c+7QQWzzMddpkXGOc5w+NLvNCMjjfFmTPkEPK9ddZxoPfiqkeJJpktFrFo7DLB4DbjxbcvNHKyHHkK07rIqA1cXZutw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2/26/26 5:08 PM, David Hildenbrand (Arm) wrote: > >>> >>>> +            pte_t pteval = ptep_get(pvmw.pte); >>> >>> I wonder if there could be a way to avoid this ptep_get() by letting >>> page_vma_mapped_walk() just provide the last value it used (in >>> check_pte() I guess). Something for another patch. >> >> Well, we’d need to add a new field to ‘struct page_vma_mapped_walk’ to >> store the last value (e.g., pvmw.pteval), > > Yes. > >> but this makes me wonder if it >> is worth adding a new field just to avoid a lightweight read (which >> should have no obvious performance impact). > > You recall that ptep_get() on arm64 is not that lightweight due to > con-pte? :) > > But yeah, something for another day. OK. >>> What is "batched"? Did you mean "nr_ptes" ? Or just the initial value >>> for "nr" ? >> >> There is already an 'nr' variable in this function. "nr_ptes" sounds >> good to me, and will use it. > > You can just use "nr" here and reuse it for the existing variable? > > Both have the same semantics (nr of ptes / pages), so having a single > value might cause less confusion. Sure. Will do.