I talked with Peter Zijlstra about this, and he told me that the clearing of the PF_NO_SETAFFINITY flag was to deal with the optimization of migrate_disable/enable() that ignores tasks that have that flag set. But that optimization was removed when I did a rework of the cpu hotplug code. I found that ignoring tasks that had that flag set would cause those tasks to not sync with the hotplug code and cause the kernel to crash. Thus it needed to not treat them special and those tasks had to go though the same work as tasks without that flag set. Now that those tasks are not treated special, there's no reason to clear the flag. May still need to be tested as the migrate_me() code does not ignore those flags. Cc: stable-rt@xxxxxxxxxxxxxxx Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> --- diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ce80b93..352239e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1393,12 +1393,6 @@ out: } } - /* - * Clear PF_NO_SETAFFINITY, otherwise we wreckage - * migrate_disable/enable. See optimization for - * PF_NO_SETAFFINITY tasks there. - */ - p->flags &= ~PF_NO_SETAFFINITY; return dest_cpu; } -- To unsubscribe from this list: send the line "unsubscribe stable-rt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
