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 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 821DECEBF92 for ; Mon, 17 Nov 2025 16:53:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=AjBcC8MJ5ncNRd+FxyETkJed/HhN2WH8VIoZ1KVckmI=; b=b/VYXxiiAg8zV98oGachwg4cEu c91S7ozSqPOT6aptsrrLdj53Zw/vKlN9B78hajqFETnoLSaEvgSyLP/KWNejtB1ZfE3DXWQWK/NH0 s76aNubfnMcN3/ptGbKXSTNv1W7m7+KthDPL7rRyVHBolGAW9YhCo1bID9T3vxwN16xLTCllrTMy1 9EGyUwFeEJN9PFD9g6nrjMnH4BQ/qcP3TJeQQZbH7+3DKc3Lc3WpvqTjUkBajXXDwmjqQxu92MDEh NyA9mrLUtFA0uzO06jNUnjz5UN195TqSmC0xq9WtQY6TMeIQv2P65mcnuT63s1bdPoZh/F2rUJGu4 KnSlarag==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vL2UF-0000000GQsk-3azc; Mon, 17 Nov 2025 16:53:55 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vL2UA-0000000GQqL-1Mfl; Mon, 17 Nov 2025 16:53:53 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 504284062C; Mon, 17 Nov 2025 16:53:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4FD96C4CEF1; Mon, 17 Nov 2025 16:53:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763398429; bh=xcaskcSeK6dNzaCv0moe8ATxJ9XohqfqvmJEObNmum4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=auYCSxxEolEdVdPP5hVqXRlt7AuV/UT6WrPa29QCtPBvB6LhWtxK/veNm59+tg6iq rWqGh7NFp27ucHsHpE+PxOZC6j5PxVDjo5pOnD0QHkrYbGowV5ij7ERUBYhkkveU8s Qzg6TBFQc+DUeNZ14jTGRDww4CnIYZTFis12VZGpJEwzucgudCK3WO/qGAhAPMC7y/ uuneSx1mR/5L0/EYwLyIp6CPdn57YNuXiEoHNjZnllcUZGQFacQDKvwPIybR0ThFFp q5NSzE8k0Nzvt6Mn+oVgHtGvj1wYQsVXpn4r7yvTJbgDFs0FNmoLC3DfEgh3t0L6cE NX3xoTtWTQtMg== Message-ID: <83e88171-54cb-4112-a344-f6a7d7f13784@kernel.org> Date: Mon, 17 Nov 2025 17:53:42 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/7] enable PT_RECLAIM on all 64-bit architectures To: Qi Zheng , will@kernel.org, aneesh.kumar@kernel.org, npiggin@gmail.com, peterz@infradead.org, dev.jain@arm.com, akpm@linux-foundation.org, ioworker0@gmail.com Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-um@lists.infradead.org, Qi Zheng References: From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251117_085350_388300_011DED89 X-CRM114-Status: UNSURE ( 8.01 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On 14.11.25 12:11, Qi Zheng wrote: > From: Qi Zheng > > Hi all, > > This series aims to enable PT_RECLAIM on all 64-bit architectures. > > On a 64-bit system, madvise(MADV_DONTNEED) may cause a large number of empty PTE > page table pages (such as 100GB+). To resolve this problem, we need to enable > PT_RECLAIM, which depends on MMU_GATHER_RCU_TABLE_FREE. > Makes sense! > Therefore, this series first enables MMU_GATHER_RCU_TABLE_FREE on all 64-bit > architectures, and finally makes PT_RECLAIM depend on MMU_GATHER_RCU_TABLE_FREE > && 64BIT. This way, PT_RECLAIM can be enabled by default on all 64-bit > architectures. Could we then even go ahead and stop making PT_RECLAIM user-selectable? -- Cheers David