[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 <venkatesh.pallipadi@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index f52facc..3162010 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1015,6 +1015,10 @@
{
unsigned int cpu = sys_dev->id;
int retval;
+
+ if (cpu_is_offline(cpu))
+ return 0;
+
if (unlikely(lock_policy_rwsem_write(cpu)))
BUG();