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 55CB4CD68E1 for ; Tue, 10 Oct 2023 00:22:02 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=uQroNQB6; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4S4Gmm6Jpbz3cm9 for ; Tue, 10 Oct 2023 11:22:00 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=uQroNQB6; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux-foundation.org (client-ip=2604:1380:4601:e00::1; helo=ams.source.kernel.org; envelope-from=akpm@linux-foundation.org; receiver=lists.ozlabs.org) Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) (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 4S4Glq5wPfz2yGv for ; Tue, 10 Oct 2023 11:21:10 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id 24A1BB8092E; Tue, 10 Oct 2023 00:21:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D9ABC433C7; Tue, 10 Oct 2023 00:20:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1696897264; bh=M2oTNjw+9oq9sArieyw8dMMJbRTMAqtdZlPZHyT7WZI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=uQroNQB6k9niizpuC63Fv9XYLdlrpW9Bngk5KLAi5UgTJ0dWDAlqM1+rDzHRmGwqd lLJ3q8SiOEEdslQ7bN/Q4s/CPzA7AyOORjiP90Km+SwxICg3mRocb8bvgCiY+4DJfw Mc5plxr0GwlubQrxCTRJ0fTbVOWmk3liNJnBW7i0= Date: Mon, 9 Oct 2023 17:20:29 -0700 From: Andrew Morton To: Michael Ellerman Subject: Re: [PATCH v6 4/9] mm: thp: Introduce anon_orders and anon_always_mask sysfs files Message-Id: <20231009172029.e558c08dd90d9b94fec3a036@linux-foundation.org> In-Reply-To: <87fs2mrqld.fsf@mail.lhotse> References: <20230929114421.3761121-1-ryan.roberts@arm.com> <20230929114421.3761121-5-ryan.roberts@arm.com> <20230929155530.a51e68e03e47a06b6b84c689@linux-foundation.org> <87fs2mrqld.fsf@mail.lhotse> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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: David Hildenbrand , Catalin Marinas , Yang Shi , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Yu Zhao , "Aneesh Kumar K.V" , Hugh Dickins , Matthew Wilcox , Vlastimil Babka , Zi Yan , "Huang, Ying" , Ryan Roberts , Anshuman Khandual , John Hubbard , David Rientjes , Itaru Kitayama , linux-arm-kernel@lists.infradead.org, Yin Fengwei , Luis Chamberlain , 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 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?