From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Wed, 19 Jan 2005 05:11:18 +0000 Subject: Re: pipe performance regression on ia64 Message-Id: <16877.60406.192245.106565@napali.hpl.hp.com> List-Id: References: <200501181741.j0IHfGf30058@unix-os.sc.intel.com> <41ED9D06.1070301@yahoo.com.au> In-Reply-To: <41ED9D06.1070301@yahoo.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Nick Piggin Cc: Linus Torvalds , "Luck, Tony" , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org >>>>> On Wed, 19 Jan 2005 10:34:30 +1100, Nick Piggin said: Nick> David I remember you reporting a pipe bandwidth regression, Nick> and I had a patch for it, but that hurt other workloads, so I Nick> don't think we ever really got anywhere. I've recently begun Nick> having another look at the multiprocessor balancer, so Nick> hopefully I can get a bit further with it this time. While it may be worthwhile to improve the scheduler, it's clear that there isn't going to be a trivial "fix" for this issue, especially since it's not even clear that anything is really broken. Independent of the scheduler work, it would be very useful to have a pipe benchmark which at least made the dependencies on the scheduler obvious. So I think improving the scheduler and improving the LMbench pipe benchmark are entirely complementary. --david