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>
This commit is contained in:
Suresh Siddha 2012-04-20 17:08:50 -07:00 committed by Thomas Gleixner
parent 9a13472374
commit 3bb5d2ee39
4 changed files with 32 additions and 57 deletions

View file

@ -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 @@ void __init smp_init(void)
{
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)