From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 15 Jul 2002 09:02:40 -0500 From: Dave McCracken Subject: Re: [PATCH] Optimize away pte_chains for single mappings Message-ID: <10930000.1026741760@baldur.austin.ibm.com> In-Reply-To: References: <55160000.1026239746@baldur.austin.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: Daniel Phillips Cc: Linux Memory Management List-ID: --On Saturday, July 13, 2002 03:13:35 PM +0200 Daniel Phillips wrote: > Why are we using up valuable real estate in page->flags when the low bit > of page->pte_chain is available? Right now my flag is bit number 18 in page->flags out of 32. Mechanisms already exist to manipulate this bit in a reasonable fashion. I don't see any good reason for complicating things by putting a flag bit into a pointer, where we'd have to repeatedly check and clear it before we dereference the pointer. When I discussed this with Rik he said putting it in flags was reasonable. We can always revisit it in the future if we run out of bits. Dave ====================================================================== Dave McCracken IBM Linux Base Kernel Team 1-512-838-3059 dmccr@us.ibm.com T/L 678-3059 -- 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/