Messages in this thread | | | Date | Tue, 12 Jan 2016 13:01:09 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [RFC][4.1.15-rt17 PATCH] mm: swap: lru drain don't use workqueue with PREEMPT_RT_FULL |
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On Sun, 10 Jan 2016, l@dorileo.org wrote: > +#ifdef CONFIG_PREEMPT_RT_FULL > +void lru_add_drain_all(void) > +{ > + static DEFINE_MUTEX(lock); > + int cpu; > + > + mutex_lock(&lock); > + get_online_cpus(); > + > + for_each_online_cpu(cpu) { > + smp_call_function_single(cpu, lru_add_drain, NULL, 1);
How is that supposed to work on RT? Not at all, because lru_add_drain() takes 'sleeping' spinlocks and you cannot do that from hard interrupt context.
Enable lockdep (what you should have done before posting) and watch the fireworks.
Thanks,
tglx
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