From: Zwane Mwaikambo We take down ksoftirqds at CPU_DEAD time, so there is a brief period whereupon there is a ksoftirqd thread for an offline processor, it is at this point that ->cpus_allowed won't have it pinned anymore. An online processor would then take down that ksoftirqd and exit it. Ensure that we only offline the processor when it's safe and never run softirqs in another processor's ksoftirqd context. This also gets rid of the warnings in ksoftirqd on cpu offline. Signed-off-by: Zwane Mwaikambo Acked-by: Ingo Molnar Signed-off-by: Andrew Morton --- 25-akpm/kernel/softirq.c | 12 ++++++++---- 1 files changed, 8 insertions(+), 4 deletions(-) diff -puN kernel/softirq.c~run-softirqs-on-proper-processor-on-offline kernel/softirq.c --- 25/kernel/softirq.c~run-softirqs-on-proper-processor-on-offline 2005-03-07 20:41:40.000000000 -0800 +++ 25-akpm/kernel/softirq.c 2005-03-07 20:41:40.000000000 -0800 @@ -355,8 +355,12 @@ static int ksoftirqd(void * __bind_cpu) set_current_state(TASK_INTERRUPTIBLE); while (!kthread_should_stop()) { - if (!local_softirq_pending()) + preempt_disable(); + if (!local_softirq_pending()) { + preempt_enable_no_resched(); schedule(); + preempt_disable(); + } __set_current_state(TASK_RUNNING); @@ -364,14 +368,14 @@ static int ksoftirqd(void * __bind_cpu) /* Preempt disable stops cpu going offline. If already offline, we'll be on wrong CPU: don't process */ - preempt_disable(); if (cpu_is_offline((long)__bind_cpu)) goto wait_to_die; do_softirq(); - preempt_enable(); + preempt_enable_no_resched(); cond_resched(); + preempt_disable(); } - + preempt_enable(); set_current_state(TASK_INTERRUPTIBLE); } __set_current_state(TASK_RUNNING); _