From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 23 Jan 2004 16:04:35 -0800 From: William Lee Irwin III Subject: Re: Can a page be HighMem without having the HighMem flag set? Message-ID: <20040124000435.GC1016@holomorphy.com> References: <1074824487.12774.185.camel@laptop-linux> <20040123022617.GY1016@holomorphy.com> <1074828647.12774.212.camel@laptop-linux> <1074900629.2024.44.camel@laptop-linux> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1074900629.2024.44.camel@laptop-linux> Sender: owner-linux-mm@kvack.org Return-Path: To: Nigel Cunningham Cc: Linux Memory Management List-ID: On Sat, Jan 24, 2004 at 12:30:29PM +1300, Nigel Cunningham wrote: > <4> BIOS-e820: 0000000000000000 - 000000000009e000 (usable) > <4> BIOS-e820: 000000000009e000 - 00000000000a0000 (reserved) > <4> BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved) > <4> BIOS-e820: 0000000000100000 - 00000000efff6500 (usable) > <4> BIOS-e820: 00000000efff6500 - 00000000f0000000 (ACPI data) > <4> BIOS-e820: 00000000fffb0000 - 0000000100000000 (reserved) > <4> BIOS-e820: 0000000100000000 - 0000000400000000 (usable) > It's the pages efff6000- which are causing me grief. if I understand > things correctly, page_is_ram is returning 0 for those pages, and as a > result they get marked reserved and not HighMem by one_highpage_init. > I suppose, then, that I need to check for and ignore pages > > highstart_pfn where PageHighMem is not set/Reserved is set. (Either > okay?). If it's reserved, most/all bets are off -- only the "owner" of the thing understands what it is. Some more formally-defined semantics for reserved are needed, but 2.6 is unlikely to get them soon. -- wli -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org