From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 A48831103; Tue, 16 Apr 2024 16:31:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713285115; cv=none; b=MjJuASgexire5okEBkWcLvjrF84/7+5vmjGsVBnYVVupa8ApC+8sS89h1QkOTB/k1PNrPo75HENjZRDfMEu0FNpMAgJHNpMi4k9sN+Fd2apQr61HhuqQQPcWnqRxaT30aEzSqeHpa64Fp1cEjVwZdbBBhlbsUENkkeDrLhbfJf0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713285115; c=relaxed/simple; bh=H3p8m8mV2JkAiJUzY7gAd1xSzJUq5Su2mpe/YPvfz98=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=J+yIVIBZ74ZXJNV23VkXcw7Nmjd7dxv4QVRsgNpuHHdc/xH3o0se2htj9lBRyPZHxXPxQ799kc/BcrTcR5Na/wxMjvQdb6vAKloA/zsqhP7k5hGiJPvAxgDMa/HSrD18z4xmL15VKtYdbDx34mANrsTXSjoGHU8bUDW9a/SD8QY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=TpE9WHNu; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="TpE9WHNu" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Zrxy/XX7+JuExrNVQ3X4tsqs9uLcDU9DwQc0CqefZDs=; b=TpE9WHNujzzZA/S3V2p4urVEPj R7bkoCWwWxSe7r+t8li4lsQD8ZzZItB+Zkbqc/dsdOTG8bYRwUatjQskVdkNgGcu4IhKO5oWVGOd1 Urh4V8W4fbVs0l6AFTLU9BEeGCPP6pGVjM8TGPWH+tCzQGiGXPhh+U7FWm+980jhrd/JT2yAK5oHq pwFJaEmv8V6zxGBk/MLFWt56H8SOyBGsdAVFnXY7M4sbJyL732ZLrQtV6JKgaFlSPtxW70/EqOkGG TXaLlkKZzVWIbrQWTfQ+oXJRRmzbvNVk9PIUUbnFcYxo1v/8uqgD8NGr0x5ojmcoCfySBR9yZVdT5 xXWOBcow==; Received: from willy by casper.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1rwlip-00000000w58-1RyL; Tue, 16 Apr 2024 16:31:51 +0000 Date: Tue, 16 Apr 2024 17:31:51 +0100 From: Matthew Wilcox To: Mike Rapoport Cc: Nam Cao , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , Christian Brauner , Andreas Dilger , Al Viro , linux-fsdevel , Jan Kara , Linux Kernel Mailing List , linux-riscv@lists.infradead.org, Theodore Ts'o , Ext4 Developers List , Conor Dooley , Anders Roxell , Alexandre Ghiti Subject: Re: riscv32 EXT4 splat, 6.8 regression? Message-ID: References: <20240416-deppen-gasleitung-8098fcfd6bbd@brauner> <8734rlo9j7.fsf@all.your.base.are.belong.to.us> <20240416171713.7d76fe7d@namcao> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Apr 16, 2024 at 07:19:27PM +0300, Mike Rapoport wrote: > > "last page of the first gigabyte" - why first gigabyte? Do you mean > > last page of *last* gigabyte? > > With 3G-1G split linear map can map only 1G from 0xc0000000 to 0xffffffff > (or 0x00000000 with 32-bit overflow): > > [ 0.000000] lowmem : 0xc0000000 - 0x00000000 (1024 MB) ... but you can't map that much. You need to reserve space for (may not be exhaustive): - PCI BARs (or other MMIO) - vmap - kmap - percpu - ioremap - modules - fixmap - Maybe EFI runtime services? You'll be lucky to get 800MB of ZONE_NORMAL.