Mark Rutland 5101ef20f0 perf/arm: Special-case hetereogeneous CPUs ... Commit: 2665784850 ("perf/core: Verify we have a single perf_hw_context PMU") forcefully prevents multiple PMUs from sharing perf_hw_context, as this generally doesn't make sense. It is a common bug for uncore PMUs to use perf_hw_context rather than perf_invalid_context, which this detects. However, systems exist with heterogeneous CPUs (and hence heterogeneous HW PMUs), for which sharing perf_hw_context is necessary, and possible in some limited cases. To make this work we have to perform some gymnastics, as we did in these commits: 66eb579e66 ("perf: allow for PMU-specific event filtering") c904e32a69 ("arm: perf: filter unschedulable events") To allow those systems to work, we must allow PMUs for heterogeneous CPUs to share perf_hw_context, though we must still disallow sharing otherwise to detect the common misuse of perf_hw_context. This patch adds a new PERF_PMU_CAP_HETEROGENEOUS_CPUS for this, updates the core logic to account for this, and makes use of it in the arm_pmu code that is used for systems with heterogeneous CPUs. Comments are added to make the rationale clear and hopefully avoid accidental abuse. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20160426103346.GA20836@leverpostej Signed-off-by: Ingo Molnar <mingo@kernel.org>		2016-05-05 10:13:59 +02:00
..
acpi	Merge branches 'acpi-processor' and 'acpi-cppc'	2016-03-14 14:20:33 +01:00
asm-generic	asm-generic/futex: Re-enable preemption in futex_atomic_cmpxchg_inatomic()	2016-04-21 11:06:09 +02:00
clocksource
crypto	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2016-03-17 11:33:45 -07:00
drm	drm: Loongson-3 doesn't fully support wc memory	2016-04-22 10:24:11 +10:00
dt-bindings	The clk changes for this release cycle are mostly dominated by	2016-03-23 06:06:45 -07:00
keys
kvm
linux	perf/arm: Special-case hetereogeneous CPUs	2016-05-05 10:13:59 +02:00
math-emu
media	[media] media: vb2: Fix regression on poll() for RW mode	2016-04-25 10:21:23 -03:00
memory
misc
net	switchdev: Adding complete operation to deferred switchdev ops	2016-04-24 14:23:32 -04:00
pcmcia
ras
rdma	IB/security: Restrict use of the write() interface	2016-04-28 12:03:16 -04:00
rxrpc
scsi	Merge branch 'fixes-base' into fixes	2016-04-05 06:56:47 -04:00
soc	IOMMU Updates for Linux v4.6	2016-03-22 11:57:43 -07:00
sound	ALSA: hda - Update BCLK also at hotplug for i915 HSW/BDW	2016-04-26 10:11:11 +02:00
target	target: add a new add_wwn_groups fabrics method	2016-03-30 20:06:44 -07:00
trace	Merge branch 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs	2016-04-09 10:41:34 -07:00
uapi	Merge branch 'perf/urgent' into perf/core, to pick up fixes	2016-05-05 10:12:37 +02:00
video	gpu: ipu-v3: ipu-dmfc: Rename ipu_dmfc_init_channel to ipu_dmfc_config_wait4eot	2016-03-31 11:24:33 +02:00
xen	xen-netback: re-import canonical netif header	2016-03-13 22:08:01 -04:00
Kbuild