From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 03 Feb 2003 16:09:38 -0600 From: Dave McCracken Subject: Re: [PATCH 2.5.59-mm6] Speed up task exit Message-ID: <91720000.1044310178@baldur.austin.ibm.com> In-Reply-To: <20030203134719.0a416c3b.akpm@digeo.com> References: <64880000.1043786464@baldur.austin.ibm.com> <20030203134719.0a416c3b.akpm@digeo.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: Andrew Morton Cc: linux-mm@kvack.org List-ID: --On Monday, February 03, 2003 13:47:19 -0800 Andrew Morton wrote: > Sorry David, I just haven't had time to play with this. I did some quick > testing on uniprocessor shell-script-intensive loads and saw no > bottom-line change at all. > > What load did you test with? I used a simple test program that forks a null child and waits for it to exit. It does it multiple times (default 100) and times the aggregate time, then computes an average. Like I said, I saw roughly 10% improvement in that test with my patch. I'm surprised that shell scripts wouldn't show an improvement. I expected they'd be more sensitive to exit performance, given how they highlighted the performance issues with shared page tables. My original reason for attacking clear_all_pages was because it kept showing up in my profiling as significant, and a quick examination of it looked like it had significant overhead that could be eliminated by keeping a few reference counts. 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/