From mboxrd@z Thu Jan 1 00:00:00 1970 From: Erich Focht Date: Mon, 22 Jul 2002 13:59:41 +0000 Subject: [Linux-ia64] node affine NUMA scheduler Message-Id: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org There's a new version of the node affine NUMA scheduler extension based on the O(1) scheduler at http://home.arcor.de/efocht/sched/Nod18_2.4.18-ia64-O1ef7.patch The patch is for 2.4.18 kernels and it has been tested on IA64 systems. It requires the O(1) scheduler patch with the corrected complex macros which I posted to the LSE and linux-ia64 mailing lists last week. For IA64 you should use: http://home.arcor.de/efocht/sched/O1_ia64-ef7-2.4.18.patch.bz2 which should be applied to 2.4.18 + ia64-020622 patch. For IA32 (NUMA-Q) try instead: http://home.arcor.de/efocht/sched/O1_i386-ef7-2.4.18.patch.bz2 What is it good for? - Extends the scheduler to NUMA. - Each task gets a homenode assigned at start (initial load balancing). - A memory affinity patch (like discontigmem, or similar) should take care that the memory of the task is allocated mainly from its homenode. - The scheduler attracts the tasks to their homenodes while trying to keep the nodes equally balanced. - Target: keep processes and their memory on the same node to reduce memory access latencies without having to fiddle with the cpus_allowed masks (hard affinities). - Within one node, behaves like the normal O(1) scheduler. For an overview over the features have a look at: http://home.arcor.de/efocht/sched There are several changes compared to the previous version, the most important ones are: - Extension to multilevel NUMA hierarchy by implementing delays when stealing tasks from remote nodes. - Better selection of task to be stolen from busiest runqueue. Take into account cache coolness, node and supernode of task and runqueue. Comments and feedback are very wellcome. Regards, Erich