commit 4ab0a9409af5fad74ad1fc9e46d5a8b460f353e9
author Rusty Russell <rusty@rustcorp.com.au> Sat Jan 10 21:58:09 2009 -0800
committer Ingo Molnar <mingo@elte.hu> Fri Jan 30 15:47:34 2009 +0100
tree d6c5bba1ffb35c5655a736d6d736d086ed3316eb
parent 3a9f84d354ce1e19956083c8e691727dea33bd5a

cpumask: convert lib/smp_processor_id to new cpumask ops

Impact: fix debug_smp_processor_id() for CONFIG_CPUMASK_OFFSTACK=y

The scheduler now uses the new cpumask API, which deals up to
nr_cpumask_bits, whereas the API used NR_CPUS bits.

If CONFIG_CPUMASK_OFFSTACK=y these two are not equal, so the top bits
are undefined.  Leading to bug 12518 "BUG: using smp_processor_id() in
preemptible [00000000] code: dellWirelessCtl/..."

The fix is simple: use the modern API in the check.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

lib/smp_processor_id.c

diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c
index 0f8fc22..4689cb0 100644
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -22,7 +22,7 @@
 	 * Kernel threads bound to a single CPU can safely use
 	 * smp_processor_id():
 	 */
-	if (cpus_equal(current->cpus_allowed, cpumask_of_cpu(this_cpu)))
+	if (cpumask_equal(&current->cpus_allowed, cpumask_of(this_cpu)))
 		goto out;
 
 	/*