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authorJames Bottomley <jejb@mulgrave.il.steeleye.com>2006-03-21 13:05:45 -0600
committerJames Bottomley <jejb@mulgrave.il.steeleye.com>2006-03-21 13:05:45 -0600
commitd04cdb64212eb5ae6a98026a97dda626e40e8e9a (patch)
treeb6a7dbb21ccfceb915844e9a330b3d3dfcaf3c5b /arch/i386/kernel/smpboot.c
parent2f8600dff2b140096a7df781884e918a16aa90e0 (diff)
parentec1248e70edc5cf7b485efcc7b41e44e10f422e5 (diff)
Merge ../linux-2.6
Diffstat (limited to 'arch/i386/kernel/smpboot.c')
-rw-r--r--arch/i386/kernel/smpboot.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index eba7f53f8b4..7007e178379 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -1029,6 +1029,16 @@ int __devinit smp_prepare_cpu(int cpu)
int apicid, ret;
lock_cpu_hotplug();
+
+ /*
+ * On x86, CPU0 is never offlined. Trying to bring up an
+ * already-booted CPU will hang. So check for that case.
+ */
+ if (cpu_online(cpu)) {
+ ret = -EINVAL;
+ goto exit;
+ }
+
apicid = x86_cpu_to_apicid[cpu];
if (apicid == BAD_APICID) {
ret = -ENODEV;