smp, idle: Allocate idle thread for each possible cpu during boot
percpu areas are already allocated during boot for each possible cpu.
percpu idle threads can be considered as an extension of the percpu areas,
and allocate them for each possible cpu during boot.
This will eliminate the need for workqueue based idle thread allocation.
In future we can move the idle thread area into the percpu area too.
[ tglx: Moved the loop into smpboot.c and added an error check when
the init code failed to allocate an idle thread for a cpu which
should be onlined ]
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: venki@google.com
Link: http://lkml.kernel.org/r/1334966930.28674.245.camel@sbsiddha-desk.sc.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/smp.c b/kernel/smp.c
index 2f8b10e..a61294c 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -13,6 +13,8 @@
#include <linux/smp.h>
#include <linux/cpu.h>
+#include "smpboot.h"
+
#ifdef CONFIG_USE_GENERIC_SMP_HELPERS
static struct {
struct list_head queue;
@@ -669,6 +671,8 @@
{
unsigned int cpu;
+ idle_threads_init();
+
/* FIXME: This should be done in userspace --RR */
for_each_present_cpu(cpu) {
if (num_online_cpus() >= setup_max_cpus)