[PATCH] sep initializing rework

Make SEP init per-cpu, so it is hotplug safe.

Signed-off-by: Li Shaohua<shaohua.li@intel.com>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index ad74a46e9ef0..c5517f332309 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -449,7 +449,18 @@ static void __init start_secondary(void *unused)
          * the local TLBs too.
          */
         local_flush_tlb();
+
+        /*
+         * We need to hold call_lock, so there is no inconsistency
+         * between the time smp_call_function() determines number of
+         * IPI receipients, and the time when the determination is made
+         * for which cpus receive the IPI. Holding this
+         * lock helps us to not include this cpu in a currently in progress
+         * smp_call_function().
+         */
+        lock_ipi_call_lock();
         cpu_set(smp_processor_id(), cpu_online_map);
+        unlock_ipi_call_lock();
 
         /* We can take interrupts now: we're officially "up". */
         local_irq_enable();