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[PATCH] sched: disable interrupts for locking in load_balance()

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Interrupts must be disabled for request queue locks if we want to run
load_balance() with interrupts enabled.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Peter Williams <pwil3058@bigpond.net.au>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Christoph Lameter 2006-12-10 02:20:21 -08:00 committed by Linus Torvalds
parent 4211a9a2e9
commit fe2eea3faf
1 changed files with 6 additions and 5 deletions
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11
kernel/sched.c
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@ -2546,8 +2546,6 @@ static inline unsigned long minus_1_or_zero(unsigned long n)
/*
* Check this_cpu to ensure it is balanced within domain. Attempt to move
* tasks if there is an imbalance.
*
* Called with this_rq unlocked.
*/
static int load_balance(int this_cpu, struct rq *this_rq,
struct sched_domain *sd, enum idle_type idle)
@ -2557,6 +2555,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
unsigned long imbalance;
struct rq *busiest;
cpumask_t cpus = CPU_MASK_ALL;
unsigned long flags;
/*
* When power savings policy is enabled for the parent domain, idle
@ -2596,11 +2595,13 @@ static int load_balance(int this_cpu, struct rq *this_rq,
* still unbalanced. nr_moved simply stays zero, so it is
* correctly treated as an imbalance.
*/
local_irq_save(flags);
double_rq_lock(this_rq, busiest);
nr_moved = move_tasks(this_rq, this_cpu, busiest,
minus_1_or_zero(busiest->nr_running),
imbalance, sd, idle, &all_pinned);
double_rq_unlock(this_rq, busiest);
local_irq_restore(flags);
/* All tasks on this runqueue were pinned by CPU affinity */
if (unlikely(all_pinned)) {
@ -2617,13 +2618,13 @@ static int load_balance(int this_cpu, struct rq *this_rq,
if (unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2)) {
spin_lock(&busiest->lock);
spin_lock_irqsave(&busiest->lock, flags);
/* don't kick the migration_thread, if the curr
* task on busiest cpu can't be moved to this_cpu
*/
if (!cpu_isset(this_cpu, busiest->curr->cpus_allowed)) {
spin_unlock(&busiest->lock);
spin_unlock_irqrestore(&busiest->lock, flags);
all_pinned = 1;
goto out_one_pinned;
}
@ -2633,7 +2634,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
busiest->push_cpu = this_cpu;
active_balance = 1;
}
spin_unlock(&busiest->lock);
spin_unlock_irqrestore(&busiest->lock, flags);
if (active_balance)
wake_up_process(busiest->migration_thread);