From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 18 Aug 2005 09:04:41 -0700 (PDT) From: Christoph Lameter Subject: Re: pagefault scalability patches In-Reply-To: <20050817174359.0efc7a6a.akpm@osdl.org> Message-ID: References: <20050817151723.48c948c7.akpm@osdl.org> <20050817174359.0efc7a6a.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: torvalds@osdl.org, hugh@veritas.com, piggin@cyberone.com.au, linux-mm@kvack.org List-ID: On Wed, 17 Aug 2005, Andrew Morton wrote: > d) the fact that some architectures will be using atomic pte ops and > others will be using page_table_lock in core MM code. We could generally go to atomic pte operations. But this would require extensive changes to all architectures. There is a tradeoff between atomic operations and using regular loads and stores on page table entries. If a number of page table entries have to be modified then it is advantageous to take a lock. If an individial entry is modified then it is better to do an atomic operation. > Using different locking/atomicity schemes in different architectures > has obvious complexity and test coverage drawbacks. We could require the same locking scheme for all architectures. Some architectures would then have to simulate the atomicity which would cause performance loss. -- 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: email@kvack.org