powerpc/mm/nohash: Ignore NULL stale_map entries

This happens with threads that are offline due to CPU hotplug
(including threads that were never "plugged in" to begin with because
SMT is disabled).

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Scott Wood 2013-03-20 19:06:12 -05:00 committed by Benjamin Herrenschmidt
parent 35fd219a26
commit 39a421ff0b

View file

@ -112,8 +112,10 @@ static unsigned int steal_context_smp(unsigned int id)
*/
for_each_cpu(cpu, mm_cpumask(mm)) {
for (i = cpu_first_thread_sibling(cpu);
i <= cpu_last_thread_sibling(cpu); i++)
__set_bit(id, stale_map[i]);
i <= cpu_last_thread_sibling(cpu); i++) {
if (stale_map[i])
__set_bit(id, stale_map[i]);
}
cpu = i - 1;
}
return id;
@ -272,7 +274,8 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next)
/* XXX This clear should ultimately be part of local_flush_tlb_mm */
for (i = cpu_first_thread_sibling(cpu);
i <= cpu_last_thread_sibling(cpu); i++) {
__clear_bit(id, stale_map[i]);
if (stale_map[i])
__clear_bit(id, stale_map[i]);
}
}