From 47b8ea7186aae7f474ec4c98f43eaa8da719cd83 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Mon, 9 Mar 2015 12:12:08 -0400 Subject: [PATCH] cpusets, isolcpus: exclude isolcpus from load balancing in cpusets Ensure that cpus specified with the isolcpus= boot commandline option stay outside of the load balancing in the kernel scheduler. Operations like load balancing can introduce unwanted latencies, which is exactly what the isolcpus= commandline is there to prevent. Previously, simply creating a new cpuset, without even touching the cpuset.cpus field inside the new cpuset, would undo the effects of isolcpus=, by creating a scheduler domain spanning the whole system, and setting up load balancing inside that domain. The cpuset root cpuset.cpus file is read-only, so there was not even a way to undo that effect. This does not impact the majority of cpusets users, since isolcpus= is a fairly specialized feature used for realtime purposes. Cc: Peter Zijlstra Cc: Clark Williams Cc: Li Zefan Cc: Ingo Molnar Cc: Luiz Capitulino Cc: Mike Galbraith Cc: cgroups@vger.kernel.org Signed-off-by: Rik van Riel Tested-by: David Rientjes Acked-by: Peter Zijlstra (Intel) Acked-by: David Rientjes Acked-by: Zefan Li Signed-off-by: Tejun Heo --- Reading git-format-patch failed