Enable PID_IN_CONTEXTIDR by default when Arm SPE is enabled.
This flag is required to get PID data in the SPE trace. Without
it the perf tool will report 0 for PID which isn't very useful,
especially when doing system wide profiling or profiling
applications that fork.
There is a small performance overhead when enabling
PID_IN_CONTEXTIDR, but SPE itself is optional and not enabled by
default so the impact is minimised.
Cc: Will Deacon <w...@kernel.org>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: Al Grant <al.gr...@arm.com>
Cc: Leo Yan <leo....@linaro.org>
Cc: John Garry <john.ga...@huawei.com>
Cc: Suzuki K Poulose <suzuki.poul...@arm.com>
Signed-off-by: James Clark <james.cl...@arm.com>
---
drivers/perf/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index 130327ff0b0e..47ede46c3d57 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -125,6 +125,7 @@ config XGENE_PMU
config ARM_SPE_PMU
tristate "Enable support for the ARMv8.2 Statistical Profiling
Extension"
depends on ARM64
+ select PID_IN_CONTEXTIDR
help
Enable perf support for the ARMv8.2 Statistical Profiling
Extension, which provides periodic sampling of operations in
--
2.28.0
