Messages in this thread Patch in this message | | | Date | Wed, 07 Mar 2007 08:24:44 -0600 | Subject | [PATCH 1/1] hotplug cpu: migrate a task within its cpuset | From | (Cliff Wickman) |
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From: Cliff Wickman <cpw@sgi.com>
When a cpu is disabled, move_task_off_dead_cpu() is called for tasks that have been running on that cpu.
Currently, such a task is migrated: 1) to any cpu on the same node as the disabled cpu, which is both online and among that task's cpus_allowed 2) to any cpu which is both online and among that task's cpus_allowed
But the task's cpus_allowed may have been a single cpu.
This patch would insert a preference to migrate such a task to a cpu within its cpuset (and set its cpus_allowed to its cpuset).
With this patch, migrate the task to: 1) to any cpu on the same node as the disabled cpu, which is both online and among that task's cpus_allowed 2) to any online cpu within the task's cpuset 3) to any cpu which is both online and among that task's cpus_allowed
Diffed against 2.6.16.37
Signed-off-by: Cliff Wickman <cpw@sgi.com>
--- kernel/sched.c | 6 ++++++ 1 file changed, 6 insertions(+)
Index: linux/kernel/sched.c =================================================================== --- linux.orig/kernel/sched.c +++ linux/kernel/sched.c @@ -4602,6 +4602,12 @@ static void move_task_off_dead_cpu(int d if (dest_cpu == NR_CPUS) dest_cpu = any_online_cpu(tsk->cpus_allowed); + /* try to stay on the same cpuset */ + if (dest_cpu == NR_CPUS) { + tsk->cpus_allowed = cpuset_cpus_allowed(tsk); + dest_cpu = any_online_cpu(tsk->cpus_allowed); + } + /* No more Mr. Nice Guy. */ if (dest_cpu == NR_CPUS) { cpus_setall(tsk->cpus_allowed); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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