ARM: 5959/1: ARM: perf-events: request PMU interrupts with IRQF_NOBALANCING
commitddee87f208b6229d2910dd5930c87089dc56c87e
authorWill Deacon <will.deacon@arm.com>
Thu, 25 Feb 2010 14:04:14 +0000 (25 15:04 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Sat, 13 Mar 2010 10:50:28 +0000 (13 10:50 +0000)
tree88cc9fcbe85243dbfd5bb4d988f78268431b16f3
parenta91ed072d6135926c296a42b0b46de35e6347845
ARM: 5959/1: ARM: perf-events: request PMU interrupts with IRQF_NOBALANCING

If IRQ balancing is used on a multicore ARM system, PMU interrupt
lines may be relocated onto CPUs other than the one causing the
counter overflow. This can result in misattribution of events to
the wrong core and, in the case that the CPU handling the interrupt
has not experience counter overflow, the interrupt can be disabled
because the handler returns IRQ_NONE.

This patch adds the IRQF_NOBALANCING flag to the request_irq call
in perf_events.c.

Acked-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/kernel/perf_event.c