From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 20 Dec 2002 03:13:36 -0800 From: William Lee Irwin III Subject: Re: shared pagetable benchmarking Message-ID: <20021220111336.GH25000@holomorphy.com> References: <3E02FACD.5B300794@digeo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3E02FACD.5B300794@digeo.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Dave McCracken , linux-mm@kvack.org List-ID: On Fri, Dec 20, 2002 at 03:11:09AM -0800, Andrew Morton wrote: > Did a bit of timing and profiling. It's a uniprocessor > kernel, 7G, PAE. > The workload is application and removal of ~80 patches using > my patch scripts. Tons and tons of forks from bash. > 2.5 ends up being 13% slower than 2.4, after disabling highpte > to make it fair. 3%-odd of this is HZ=1000. So say 10%. > Pagetable sharing actually slowed this test down by several > percent overall. Which is unfortunate, because the main > thing which Linus likes about shared pagetables is that it > "speeds up forks". > Is there anything we can do to fix all of this up a bit? For testing purposes, try removing the opportunistic mmap()-time sharing. Bill -- 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/