From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: [PATCH 0 of 2] credit2: Reduce excessive cpu migration Date: Thu, 9 Dec 2010 17:55:15 +0000 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com Cc: george.dunlap@eu.citrix.com List-Id: xen-devel@lists.xenproject.org More recent processors have one L2 per core. My plan for the credit2 scheduler invovled having several cores sharing the same runqueue. I've measured the cost of excessive cross-L2 intra-L3 migrations, and while they're not excessive, they are measurable. This patch series introduces some simple heuristics to reduce unnecessary migration. As in all the Credit2 work, this is a first cut, and I'm sure there are further improvments.