From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 9 Dec 2004 15:07:13 -0800 (PST) From: Christoph Lameter Subject: Re: page fault scalability patch V12: rss tasklist vs sloppy rss In-Reply-To: <20041209225259.GG2714@holomorphy.com> Message-ID: References: <20041209225259.GG2714@holomorphy.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: William Lee Irwin III Cc: Hugh Dickins , Linus Torvalds , Andrew Morton , Benjamin Herrenschmidt , Nick Piggin , linux-mm@kvack.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org List-ID: On Thu, 9 Dec 2004, William Lee Irwin III wrote: > Unless the algorithms being compared are properly implemented, they're > straw men, not valid comparisons. Sloppy rss left the rss in the section of mm that contained the counters. So that has a separate cacheline. The idea of putting the atomic ops in a group was to only have one exclusive cacheline for mmap_sem and the rss. Which could lead to more bouncing of a single cache line rather than bouncing multiple cache lines less. But it seems to me that the problem essentially remains the same if the rss counter is not split. -- 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