From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E5B2E1E9B12; Thu, 18 Dec 2025 09:04:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766048652; cv=none; b=ugChJUkAxLf0rGqBGEuc4yA51izVht/P+hxhxZeYX11BOSMTu3W6hwbYdXAFeVAL+bU/u+e2cpSnroL61pXIpT5WD/PwX9uRCq2qvQ/wOgDgL9c/AN5jAGfQTYPj5IZzL0xT7qiUj3k5RlwSBImytwQkXfoGWkOIqjj+f4XjYnk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766048652; c=relaxed/simple; bh=K7sTzImfm/ZlD+BwDyLC75278tg9lbuRtHhwrRkkXVM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=iisWe6PTXidmXbWzev+fmkmGd2L3KjLyJltEWin7Mma3CWV7ebcpUaMi2qyNr0svMaCRP9xvdQz8nejQ2JZ9RJTNjMLvxkYOcfgHZa0/EPIPw7535+TWG9nUbuYUqtnZ6d0pPHPlJZ3OdAkpnxISDxtifWvOGywa3tEPomwMZWE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gh1ZAxfw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gh1ZAxfw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BB66C4CEFB; Thu, 18 Dec 2025 09:04:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766048650; bh=K7sTzImfm/ZlD+BwDyLC75278tg9lbuRtHhwrRkkXVM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=gh1ZAxfwbsO5kkKLAFARVWdAfKe/XY/yd5XTJu/i3WKX+vCgqYh99HDC0JLqwiryE 3SqpGL8wPV595zKDmSfDUKlAylJ1gYl3qIo9Q2cHiAYU/YaAlgERnnzV8r1ZYIJTHT qkdTB8fmsnFJ5pSfb8qIHJcCiLsASoEsc9ko5Ep6HFZScBEa+X4g0huhx4bHsLCdiE t/zpwKTewKWtI+ND88OhKI3ZqeW0IRc1ZGesJBB1lXj+TeDIBV6htkCmmBGa6hbNGY yyIuJm24mTGl+PmGqAAhfYuiuw4cyxzl2IVTuf9ZmoTQOppob5abO3OKFcTB95aRIZ pj7jntYOGr3TA== Message-ID: <87e59cd3-a554-4911-aaca-21be2080e2c6@kernel.org> Date: Thu, 18 Dec 2025 10:04:03 +0100 Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 04/28] mm: vmscan: prepare for the refactoring the move_folios_to_lru() To: Qi Zheng , hannes@cmpxchg.org, hughd@google.com, mhocko@suse.com, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, lorenzo.stoakes@oracle.com, ziy@nvidia.com, harry.yoo@oracle.com, imran.f.khan@oracle.com, kamalesh.babulal@oracle.com, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, chenridong@huaweicloud.com, mkoutny@suse.com, akpm@linux-foundation.org, hamzamahfooz@linux.microsoft.com, apais@linux.microsoft.com, lance.yang@linux.dev Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Qi Zheng References: <4a7ca63e3d872b7e4d117cf4e2696486772facb6.1765956025.git.zhengqi.arch@bytedance.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: <4a7ca63e3d872b7e4d117cf4e2696486772facb6.1765956025.git.zhengqi.arch@bytedance.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 12/17/25 08:27, Qi Zheng wrote: > From: Qi Zheng > > After refactoring the move_folios_to_lru(), its caller no longer needs to > hold the lruvec lock, the disabling IRQ is only for __count_vm_events() > and __mod_node_page_state(). > > On the PREEMPT_RT kernel, the local_irq_disable() cannot be used. To > avoid using local_irq_disable() and reduce the critical section of > disabling IRQ, make all callers of move_folios_to_lru() use IRQ-safed > count_vm_events() and mod_node_page_state(). The patch description is a bit confusing for me. I assume you mean something like "Once we refactor move_folios_to_lru(), its callers will no longer have to hold the lruvec lock; disabling IRQs is then only required for __count_vm_events() and __mod_node_page_state(). To prepare for that, let's $YOURDETAILSHERE" -- Cheers David