block: queue work on power efficient wq
Block layer uses workqueues for multiple purposes. There is no real dependency
of scheduling these on the cpu which scheduled them.
On a idle system, it is observed that and idle cpu wakes up many times just to
service this work. It would be better if we can schedule it on a cpu which the
scheduler believes to be the most appropriate one.
This patch replaces normal workqueues with power efficient versions.
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/block/blk-core.c b/block/blk-core.c
index 33c33bc..f0deb8b 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -3180,7 +3180,8 @@
/* used for unplugging and affects IO latency/throughput - HIGHPRI */
kblockd_workqueue = alloc_workqueue("kblockd",
- WQ_MEM_RECLAIM | WQ_HIGHPRI, 0);
+ WQ_MEM_RECLAIM | WQ_HIGHPRI |
+ WQ_POWER_EFFICIENT, 0);
if (!kblockd_workqueue)
panic("Failed to create kblockd\n");
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 9c4bb82..4464c82 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -144,7 +144,8 @@
if (atomic_long_dec_and_test(&ioc->refcount)) {
spin_lock_irqsave(&ioc->lock, flags);
if (!hlist_empty(&ioc->icq_list))
- schedule_work(&ioc->release_work);
+ queue_work(system_power_efficient_wq,
+ &ioc->release_work);
else
free_ioc = true;
spin_unlock_irqrestore(&ioc->lock, flags);
diff --git a/block/genhd.c b/block/genhd.c
index 20625ee..e9094b3 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1489,9 +1489,11 @@
intv = disk_events_poll_jiffies(disk);
set_timer_slack(&ev->dwork.timer, intv / 4);
if (check_now)
- queue_delayed_work(system_freezable_wq, &ev->dwork, 0);
+ queue_delayed_work(system_freezable_power_efficient_wq,
+ &ev->dwork, 0);
else if (intv)
- queue_delayed_work(system_freezable_wq, &ev->dwork, intv);
+ queue_delayed_work(system_freezable_power_efficient_wq,
+ &ev->dwork, intv);
out_unlock:
spin_unlock_irqrestore(&ev->lock, flags);
}
@@ -1534,7 +1536,8 @@
spin_lock_irq(&ev->lock);
ev->clearing |= mask;
if (!ev->block)
- mod_delayed_work(system_freezable_wq, &ev->dwork, 0);
+ mod_delayed_work(system_freezable_power_efficient_wq,
+ &ev->dwork, 0);
spin_unlock_irq(&ev->lock);
}
@@ -1627,7 +1630,8 @@
intv = disk_events_poll_jiffies(disk);
if (!ev->block && intv)
- queue_delayed_work(system_freezable_wq, &ev->dwork, intv);
+ queue_delayed_work(system_freezable_power_efficient_wq,
+ &ev->dwork, intv);
spin_unlock_irq(&ev->lock);