Patchwork powerpc/mm/nohash: ignore NULL stale_map entries

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Submitter Scott Wood
Date March 21, 2013, 12:06 a.m.
Message ID <20130321000612.GA5887@home.buserror.net>
Download mbox | patch
Permalink /patch/229525/
State Accepted
Commit 39a421ff0b7cb056e687894a9d5f57aa1303e1c8
Delegated to: Benjamin Herrenschmidt
Headers show

Comments

Scott Wood - March 21, 2013, 12:06 a.m.
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>
---
 arch/powerpc/mm/mmu_context_nohash.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

Patch

diff --git a/arch/powerpc/mm/mmu_context_nohash.c b/arch/powerpc/mm/mmu_context_nohash.c
index e779642..810f8e4 100644
--- a/arch/powerpc/mm/mmu_context_nohash.c
+++ b/arch/powerpc/mm/mmu_context_nohash.c
@@ -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]);
 		}
 	}