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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 D7CACCDB46E for ; Thu, 12 Oct 2023 09:32:25 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=Pq6dNMkA; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=Pq6dNMkA; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4S5ktw1hYXz3vXM for ; Thu, 12 Oct 2023 20:32:24 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=Pq6dNMkA; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=Pq6dNMkA; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=redhat.com (client-ip=170.10.129.124; helo=us-smtp-delivery-124.mimecast.com; envelope-from=david@redhat.com; receiver=lists.ozlabs.org) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4S5ksv6qtpz3bP4 for ; Thu, 12 Oct 2023 20:31:30 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697103085; 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=xSLDOzif9pe7NWfs6FAqs0gKz2RiKRhAj6wFDsEM4p4=; b=Pq6dNMkAOiuCb/k/pwm8uPMScd9ep9s9Z79PS5TkJNUM1TRCL1abY7/7msV19k3Ct43a7E lQVUpgjE9q9RN0upmvdP7SwqNVMqj3MuirsVmeBag8WvSfoLVO9oJ2P0CiiwOCEvHnOPeQ dke9gmKT1oPO1SPY0y72nja9pKGVsto= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697103085; 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=xSLDOzif9pe7NWfs6FAqs0gKz2RiKRhAj6wFDsEM4p4=; b=Pq6dNMkAOiuCb/k/pwm8uPMScd9ep9s9Z79PS5TkJNUM1TRCL1abY7/7msV19k3Ct43a7E lQVUpgjE9q9RN0upmvdP7SwqNVMqj3MuirsVmeBag8WvSfoLVO9oJ2P0CiiwOCEvHnOPeQ dke9gmKT1oPO1SPY0y72nja9pKGVsto= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-687-ca9lKu7VO9Kz0drKHGOv0Q-1; Thu, 12 Oct 2023 05:31:24 -0400 X-MC-Unique: ca9lKu7VO9Kz0drKHGOv0Q-1 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-32d903d35c2so297228f8f.3 for ; Thu, 12 Oct 2023 02:31:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697103081; x=1697707881; h=content-transfer-encoding:in-reply-to:organization:from:references :cc:to:content-language:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=xSLDOzif9pe7NWfs6FAqs0gKz2RiKRhAj6wFDsEM4p4=; b=JE5lOBq7Ul+oIQqwPVK7+zCT+MB9AhY9+zONzqTf1TA5u1qX9DCrZ9n7cOOjsGS0bL BqpJi6tYO6Szy6wiha+HvYqnlgMjST9gkxLwBBNkKdLuo73GPF7b8JFOc8EeFaaIm/22 iWFEMJHv3+gYzWyOihC1ip6i7l8zEwR74oq3KWwbjIPGBRXHZZv9dVay+7Tv+KBofIdG ZZtJZC7FGDuae9g2aMLCPf2X6ZQXkamkIhf0xSWm8Rd/BQXlAnivaDXxjZ/uOO3COXFa JsWOpB6IZpiYjdLocwjOa1oFcI5MdYsIaF6oWUhhkuydJTKdfTkvEmbt1+Cz0wPms3GP Q00w== X-Gm-Message-State: AOJu0Yw7VC2YgXTm0sFYbi+1n3RnVzpF+H+YdQ204i/IJ/9CCGxOk21F IMadDQpmM8VHJVNiPuUasl+ROMoOirlopsO+JwHPkaJnf3/QvBuwSS4VrncKA2Zztyr0yYewRvr iYpLpPM/Iib5uDTXZkhLqL7gA2w== X-Received: by 2002:a5d:5487:0:b0:319:6997:942e with SMTP id h7-20020a5d5487000000b003196997942emr21160883wrv.8.1697103081683; Thu, 12 Oct 2023 02:31:21 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFPzeS7uCwL+pDb1dGgHVTR29EBJnszm/PSyz58/uQ1Bkw1Kxbz5kvLADKGVnfjZ5RZryevww== X-Received: by 2002:a5d:5487:0:b0:319:6997:942e with SMTP id h7-20020a5d5487000000b003196997942emr21160852wrv.8.1697103081266; Thu, 12 Oct 2023 02:31:21 -0700 (PDT) Received: from ?IPV6:2003:cb:c70d:ee00:b271:fb6c:a931:4769? (p200300cbc70dee00b271fb6ca9314769.dip0.t-ipconnect.de. [2003:cb:c70d:ee00:b271:fb6c:a931:4769]) by smtp.gmail.com with ESMTPSA id 20-20020a05600c22d400b004054dcbf92asm981775wmg.20.2023.10.12.02.31.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 12 Oct 2023 02:31:20 -0700 (PDT) Message-ID: <0feef130-59dd-0a31-ed06-e3849a52c75e@redhat.com> Date: Thu, 12 Oct 2023 11:31:19 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH v6 4/9] mm: thp: Introduce anon_orders and anon_always_mask sysfs files To: Andrew Morton , Michael Ellerman References: <20230929114421.3761121-1-ryan.roberts@arm.com> <20230929114421.3761121-5-ryan.roberts@arm.com> <20230929155530.a51e68e03e47a06b6b84c689@linux-foundation.org> <87fs2mrqld.fsf@mail.lhotse> <20231009172029.e558c08dd90d9b94fec3a036@linux-foundation.org> From: David Hildenbrand Organization: Red Hat In-Reply-To: <20231009172029.e558c08dd90d9b94fec3a036@linux-foundation.org> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arm-kernel@lists.infradead.org, David Rientjes , Ryan Roberts , Yu Zhao , John Hubbard , Anshuman Khandual , Catalin Marinas , Yang Shi , "Huang, Ying" , Hugh Dickins , Yin Fengwei , Matthew Wilcox , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Luis Chamberlain , Vlastimil Babka , Zi Yan , "Aneesh Kumar K.V" , Itaru Kitayama , linuxppc-dev@lists.ozlabs.org, "Kirill A. Shutemov" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 10.10.23 02:20, Andrew Morton wrote: > On Sun, 08 Oct 2023 09:54:22 +1100 Michael Ellerman wrote: > >>> I don't know why powerpc's PTE_INDEX_SIZE is variable. >> >> To allow a single vmlinux to boot using either the Hashed Page Table >> MMU, or Radix Tree MMU, which have different page table geometry. >> >> That's a pretty crucial feature for distros, so that they can build a >> single kernel to boot on Power8/9/10. > > Dumb question: why can't distros ship two kernels and have the boot > loader (or something else) pick the appropriate one? One answer I keep hearing over and over again is "test matrix explosion". So distros only do it when unavoidable: for example, when differing PAGE_SIZE is required (e.g., 4k vs 64k) or we're dealing with RT support (RT vs !RT). -- Cheers, David / dhildenb