alistair23-linux/arch/ia64/sn
Thomas Gleixner 9feb42ac88 ia64/sn/hwperf: Replace racy task affinity logic
sn_hwperf_op_cpu() which is invoked from an ioctl requires to run code on
the requested cpu. This is achieved by temporarily setting the affinity of
the calling user space thread to the requested CPU and reset it to the
original affinity afterwards.

That's racy vs. CPU hotplug and concurrent affinity settings for that
thread resulting in code executing on the wrong CPU and overwriting the
new affinity setting.

Replace it by using work_on_cpu_safe() which guarantees to run the code on
the requested CPU or to fail in case the CPU is offline.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1704122251450.2548@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-04-15 12:20:53 +02:00
..
include [IA64-SGI] Older PROM WAR for device flush code 2006-01-17 10:08:37 -08:00
kernel ia64/sn/hwperf: Replace racy task affinity logic 2017-04-15 12:20:53 +02:00
pci dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
Makefile [IA64-SGI] Recursive flags do not work for selective builds 2006-01-26 13:17:34 -08:00