Messages in this thread | | | Date | Sat, 14 Jul 2007 21:39:50 +0400 | From | Oleg Nesterov <> | Subject | Re: [PATCH -rt 5/5] slub: -rt port |
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On 07/14, Peter Zijlstra wrote: > > +static void flush_all(struct kmem_cache *s) > +{ > + int cpu; > + struct workqueue_struct *wq = flush_slab_workqueue; > + > + mutex_lock(&flush_slab_mutex); > + for_each_online_cpu(cpu) { > + struct slab_work_struct *sw = &per_cpu(slab_works, cpu); > + > + INIT_WORK(&sw->work, flush_cpu_slab_wq); > + sw->s = s; > + queue_work_cpu(wq, &sw->work, cpu); > + } > + flush_workqueue(wq); > + mutex_unlock(&flush_slab_mutex); > +}
I suspect this is not cpu-hotplug safe. flush_slab_mutex doesn't protect from cpu_down(). This means that slab_work_struct could be scheduled on the already dead CPU. flush_workqueue(wq) will hang in that case.
Oleg.
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