[PATCH] Fix maxcpus=1 trigerring BUG() in cpufreq

Ingo reported it on lkml in the thread "2.6.21-rc5: maxcpus=1 crash in cpufreq: kernel BUG at drivers/cpufreq/cpufreq.c:82!" This check added to remove_dev is symmetric to one in add_dev and handles callbacks for offline cpus cleanly. Signed-off-by: Venkatesh Pallipadi <[email protected]> Acked-by: Ingo Molnar <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
huntrar · Mar 27, 2007 · ec28297 · ec28297
1 parent 703071b
commit ec28297
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
@@ -1015,6 +1015,10 @@ static int cpufreq_remove_dev (struct sys_device * sys_dev)
 {
 	unsigned int cpu = sys_dev->id;
 	int retval;
+
+	if (cpu_is_offline(cpu))
+		return 0;
+
 	if (unlikely(lock_policy_rwsem_write(cpu)))
 		BUG();