Hi Marc,
On 2016年07月01日 21:21, Marc Zyngier wrote:
On a big-little system, PMUs can be wired to CPUs using per CPU
interrups (PPI). In this case, it is important to make sure that
the enable/disable do happen on the right set of CPUs.
So instead of relying on the interrupt-affinity property, we can
use the actual percpu affinity that DT exposes as part of the
interrupt specifier. The DT binding is also updated to reflect
the fact that the interrupt-affinity property shouldn't be used
in that case.
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Tested-by: Caesar Wang <wxt@xxxxxxxxxxxxxx>
I pick this up on my local branch.
8bc671a FROMLIST: drivers/perf: arm-pmu: Handle per-interrupt affinity mask
3d723f4 FROMLIST: arm64: dts: rockchip: support the pmu node for rk3399
1359b92 FIXUP: FROMLIST: arm64: dts: rockchip: change all interrupts
cells for 4 on rk3399 SoCs
...
Tested on rk3399 board.
localhost / # perf list
List of pre-defined events (to be used in -e):
cpu-cycles OR cycles [Hardware event]
instructions [Hardware event]
cache-references [Hardware event]
cache-misses [Hardware event]
branch-instructions OR branches [Hardware event]
branch-misses [Hardware event]
bus-cycles [Hardware event]
...
perf stat --cpu 0/1/2/3..... to minitor
e.g. cpu0;
localhost / # perf stat --cpu 0
^C
Performance counter stats for 'CPU(s) 0':
3374.917571 task-clock (msec) # 1.001 CPUs utilized [100.00%]
20 context-switches # 0.006 K/sec [100.00%]
2 cpu-migrations # 0.001 K/sec [100.00%]
55 page-faults # 0.016 K/sec
7151843 cycles # 0.002 GHz [100.00%]
<not supported> stalled-cycles-frontend
<not supported> stalled-cycles-backend
4272536 instructions # 0.60 insns per cycle [100.00%]
568406 branches # 0.168 M/sec [100.00%]
65652 branch-misses # 11.55% of all branches
Also, 'perf top' to monitor the PMU interrupts from cpus
---
---
Documentation/devicetree/bindings/arm/pmu.txt | 4 +++-
drivers/perf/arm_pmu.c | 22 +++++++++++++++++-----
2 files changed, 20 insertions(+), 6 deletions(-)
diff --git a/Documentation/devicetree/bindings/arm/pmu.txt b/Documentation/devicetree/bindings/arm/pmu.txt
index 74d5417..61c8b46 100644
--- a/Documentation/devicetree/bindings/arm/pmu.txt
+++ b/Documentation/devicetree/bindings/arm/pmu.txt
@@ -39,7 +39,9 @@ Optional properties:
When using a PPI, specifies a list of phandles to CPU
nodes corresponding to the set of CPUs which have
a PMU of this type signalling the PPI listed in the
- interrupts property.
+ interrupts property, unless this is already specified
+ by the PPI interrupt specifier itself (in which case
+ the interrupt-affinity property shouldn't be present).
This property should be present when there is more than
a single SPI.
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 140436a..065ccec 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -603,7 +603,8 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
irq = platform_get_irq(pmu_device, 0);
if (irq >= 0 && irq_is_percpu(irq)) {
- on_each_cpu(cpu_pmu_disable_percpu_irq, &irq, 1);
+ on_each_cpu_mask(&cpu_pmu->supported_cpus,
+ cpu_pmu_disable_percpu_irq, &irq, 1);
free_percpu_irq(irq, &hw_events->percpu_pmu);
} else {
for (i = 0; i < irqs; ++i) {
@@ -645,7 +646,9 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
irq);
return err;
}
- on_each_cpu(cpu_pmu_enable_percpu_irq, &irq, 1);
+
+ on_each_cpu_mask(&cpu_pmu->supported_cpus,
+ cpu_pmu_enable_percpu_irq, &irq, 1);
} else {
for (i = 0; i < irqs; ++i) {
int cpu = i;
@@ -961,9 +964,18 @@ static int of_pmu_irq_cfg(struct arm_pmu *pmu)
i++;
} while (1);
- /* If we didn't manage to parse anything, claim to support all CPUs */
- if (cpumask_weight(&pmu->supported_cpus) == 0)
- cpumask_setall(&pmu->supported_cpus);
+ /* If we didn't manage to parse anything, try the interrupt affinity */
+ if (cpumask_weight(&pmu->supported_cpus) == 0) {
+ if (!using_spi) {
+ /* If using PPIs, check the affinity of the partition */
+ int irq = platform_get_irq(pdev, 0);
+ irq_get_percpu_devid_partition(irq,
+ &pmu->supported_cpus);
+ } else {
+ /* Otherwise default to all CPUs */
+ cpumask_setall(&pmu->supported_cpus);
+ }
+ }
/* If we matched up the IRQ affinities, use them to route the SPIs */
if (using_spi && i == pdev->num_resources)
--
caesar wang | software engineer | wxt@xxxxxxxxxxxxx
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