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 A7DE1CCA471 for ; Sat, 4 Oct 2025 02:37:52 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B408A8E0005; Fri, 3 Oct 2025 22:37:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B179E8E0002; Fri, 3 Oct 2025 22:37:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A2EA38E0005; Fri, 3 Oct 2025 22:37:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 937118E0002 for ; Fri, 3 Oct 2025 22:37:51 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 320B845543 for ; Sat, 4 Oct 2025 02:37:51 +0000 (UTC) X-FDA: 83958871542.01.32BCB31 Received: from out-180.mta1.migadu.com (out-180.mta1.migadu.com [95.215.58.180]) by imf04.hostedemail.com (Postfix) with ESMTP id 46B724000A for ; Sat, 4 Oct 2025 02:37:49 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=IO2KSUrz; spf=pass (imf04.hostedemail.com: domain of lance.yang@linux.dev designates 95.215.58.180 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1759545469; 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=ZtsI3lx2659ed28Hsfe3yffVn1tmzg1sTkqeGJ64sdY=; b=dIYw6eNWLg60HEfP9fvwyKPsA2DyzXV8XAy5Xh7usBTwbb8sU89Ls5hZUz2e4+59i8p0LT FfeiWBQcsanCg2q77LLwq80wYsgEbjZEDEhWiqCUO/ySIJNg+TdnBjvZZOsAgZfTRAdbHG 0W/MpQ18vjcEystQtmOiuu/YzdDjzxk= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=IO2KSUrz; spf=pass (imf04.hostedemail.com: domain of lance.yang@linux.dev designates 95.215.58.180 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1759545469; a=rsa-sha256; cv=none; b=OI17SNcGwHI8RFb7p/7rnlQ7uNbAcO+/307FJrSnbiGBWKkvABHjm+RykmNLgVKow8eEw1 qtO9sf0JwvKwN6qAsQsTNrVig+QCNN4WtC0edGfYlYKop4tyGPHNBZN3cYmWPtrO9/NMtR ebJi0Q/G/RhDaG0DDihJSqbFO7OYYJA= Message-ID: <6c4be2e8-04f5-49c6-9055-cef033716c19@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1759545467; h=from:from: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; bh=ZtsI3lx2659ed28Hsfe3yffVn1tmzg1sTkqeGJ64sdY=; b=IO2KSUrzq3V4cuTh3UvbNkBrJC37Pe4HdjZa1lIkRq+QI5SWpv8888ULk3oRQ/d9QYS8Qm 0dZg+eRRrT2guK4KsRhzfCQtFhiTwyE1bDA9xwVDVDKaG1ZxVGh47HBeZecDDyD59xJk14 O2bQfUuPDvgjzk1F/Oo+VzJwxOfh0+Q= Date: Sat, 4 Oct 2025 10:37:32 +0800 MIME-Version: 1.0 Subject: Re: [Patch v2] mm/huge_memory: add pmd folio to ds_queue in do_huge_zero_wp_pmd() Content-Language: en-US To: Wei Yang Cc: linux-mm@kvack.org, baolin.wang@linux.alibaba.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, wangkefeng.wang@huawei.com, stable@vger.kernel.org, ziy@nvidia.com, ryan.roberts@arm.com, dev.jain@arm.com, npache@redhat.com, baohua@kernel.org, akpm@linux-foundation.org, david@redhat.com References: <20251002013825.20448-1-richard.weiyang@gmail.com> <20251004020447.slfiuvu5elidwosl@master> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: <20251004020447.slfiuvu5elidwosl@master> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: 46B724000A X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: 7q9uis65iac68pdjj7des3n9ufhyc1mh X-HE-Tag: 1759545469-647346 X-HE-Meta: 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 J+g3/QEq O1wEKGW1z3a+wtDpDpAuh3/UwwG9ct0IOkAF7GVwBpmdgx1bjeUqdvhqfjtdU16kaFfCWQYtvxGEKpP5oOxv9edgm6awuLdASm1XHZncNBvcyH+KvXc4L/131D+9gmuKbNirlad9M5CMO73v/54epDOdr+Li6OeBF/XJHtiekYHuk3BSAB5ImLwMqbXP5SCXyvQ+SfcPSgZLtUbJrOs/SWqedn5stAxOh/9tISrB+/PELC8TY4xgjNl4x3I3VLPGigejsfMoz1dWFaWcA3TVcoiNiFHpWzQk+jIRV 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: List-Subscribe: List-Unsubscribe: On 2025/10/4 10:04, Wei Yang wrote: > On Fri, Oct 03, 2025 at 09:49:28PM +0800, Lance Yang wrote: >> Hey Wei, >> >> On 2025/10/2 09:38, Wei Yang wrote: >>> We add pmd folio into ds_queue on the first page fault in >>> __do_huge_pmd_anonymous_page(), so that we can split it in case of >>> memory pressure. This should be the same for a pmd folio during wp >>> page fault. >>> >>> Commit 1ced09e0331f ("mm: allocate THP on hugezeropage wp-fault") miss >>> to add it to ds_queue, which means system may not reclaim enough memory >> >> IIRC, it was commit dafff3f4c850 ("mm: split underused THPs") that >> started unconditionally adding all new anon THPs to _deferred_list :) >> > > Thanks for taking a look. > > While at this time do_huge_zero_wp_pmd() is not introduced, how it fix a Ah, I see. I was focused on the policy change ... > non-exist case? And how could it be backported? I am confused here. And, yes, 1ced09e0331f ("mm: allocate THP on hugezeropage wp-fault") was merged later and it introduced the new do_huge_zero_wp_pmd() path without aligning with the policy ... Thanks for clarifying! Lance > >>> in case of memory pressure even the pmd folio is under used. >>> >>> Move deferred_split_folio() into map_anon_folio_pmd() to make the pmd >>> folio installation consistent. >>> >>> Fixes: 1ced09e0331f ("mm: allocate THP on hugezeropage wp-fault") >> >> Shouldn't this rather be the following? >> >> Fixes: dafff3f4c850 ("mm: split underused THPs") >> >> Thanks, >> Lance >