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 8C754301484; Mon, 17 Nov 2025 16:53:49 +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=1763398429; cv=none; b=mPlrr1G5uk85u4uplxmdrsmBqBhSt1+u05nA2kZtkx9gfYTNzIeStzBmglscUPQXIk0Su/wxAwVjrBfejCT1cbPubwzp1cxNALuMxK3CxvIlrutEKEAt++/zGHBx98PPmSsLAhOj0gkVf+OIVtnoOmEkzszFmBYorADKjoqUgeE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763398429; c=relaxed/simple; bh=xcaskcSeK6dNzaCv0moe8ATxJ9XohqfqvmJEObNmum4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=W9lcjouSkt73qgdkw4oAnq++uRmGQWZAj5u34sr5yQo9d+XhiQPRZojHbjNnZM+TjeSsl8j5LrdkllrPoXsiaCelg3HFNN3oT3cD2ggeZfsMJfOBz0gBv/eecmlxL7cgarF9KmrfWUaBgzOPAWyTTWnYfeFRKfQMp0ORmHKlAM8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=auYCSxxE; 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="auYCSxxE" 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 Precedence: bulk X-Mailing-List: linux-parisc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 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