irq_work: Add generic hardirq context callbacks

Provide a mechanism that allows running code in IRQ context. It is
most useful for NMI code that needs to interact with the rest of the
system -- like wakeup a task to drain buffers.

Perf currently has such a mechanism, so extract that and provide it as
a generic feature, independent of perf so that others may also
benefit.

The IRQ context callback is generated through self-IPIs where
possible, or on architectures like powerpc the decrementer (the
built-in timer facility) is set to generate an interrupt immediately.

Architectures that don't have anything like this get to do with a
callback from the timer tick. These architectures can call
irq_work_run() at the tail of any IRQ handlers that might enqueue such
work (like the perf IRQ handler) to avoid undue latencies in
processing the work.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[ various fixes ]
Signed-off-by: Huang Ying <ying.huang@intel.com>
LKML-Reference: <1287036094.7768.291.camel@yhuang-dev>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra
2010-10-14 14:01:34 +08:00
committed by Ingo Molnar
parent 8e5fc1a732
commit e360adbe29
39 changed files with 311 additions and 242 deletions

View File

@@ -1092,7 +1092,7 @@ armv6pmu_handle_irq(int irq_num,
* platforms that can have the PMU interrupts raised as an NMI, this
* will not work.
*/
perf_event_do_pending();
irq_work_run();
return IRQ_HANDLED;
}
@@ -2068,7 +2068,7 @@ static irqreturn_t armv7pmu_handle_irq(int irq_num, void *dev)
* platforms that can have the PMU interrupts raised as an NMI, this
* will not work.
*/
perf_event_do_pending();
irq_work_run();
return IRQ_HANDLED;
}
@@ -2436,7 +2436,7 @@ xscale1pmu_handle_irq(int irq_num, void *dev)
armpmu->disable(hwc, idx);
}
perf_event_do_pending();
irq_work_run();
/*
* Re-enable the PMU.
@@ -2763,7 +2763,7 @@ xscale2pmu_handle_irq(int irq_num, void *dev)
armpmu->disable(hwc, idx);
}
perf_event_do_pending();
irq_work_run();
/*
* Re-enable the PMU.