Many PMU drivers do not have the capability to exclude counting events
that occur in specific contexts such as idle, kernel, guest, etc. These
drivers indicate this by returning an error in their event_init upon
testing the events attribute flags.
However this approach requires that each time a new event modifier is
added to perf, all the perf drivers need to be modified to indicate that
they don't support the attribute. This results in additional boiler-plate
code common to many drivers that needs to be maintained. Furthermore the
drivers are not consistent with regards to the error value they return
when reporting unsupported attributes.
This patchset allow PMU drivers to advertise their inability to exclude
based on context via a new capability: PERF_PMU_CAP_NO_EXCLUDE. This
allows the perf core to reject requests for exclusion events where there
is no support in the PMU.
This is a functional change, in particular:
- Some drivers will now additionally (but correctly) report unsupported
exclusion flags. It's typical for existing userspace tools such as
perf to handle such errors by retrying the system call without the
unsupported flags.
- Drivers that do not support any exclusion that previously reported
-EPERM or -EOPNOTSUPP will now report -EINVAL - this is consistent
with the majority and results in userspace perf retrying without
exclusion.
All drivers touched by this patchset have been compile tested.
Changes from v2:
- Invert logic from CAP_EXCLUDE to CAP_NO_EXCLUDE
Changes from v1:
- Changed approach from explicitly rejecting events in unsupporting PMU
drivers to explicitly advertising a capability in PMU drivers that
do support exclusion events
- Added additional information to tools/perf/design.txt
- Rename event_has_exclude_flags to event_has_any_exclude_flag and
update commit log to reflect it's a function
Andrew Murray (12):
perf/doc: update design.txt for exclude_{host|guest} flags
perf/core: add function to test for event exclusion flags
perf/core: add PERF_PMU_CAP_NO_EXCLUDE for exclusion incapable PMUs
alpha: perf/core: use PERF_PMU_CAP_NO_EXCLUDE
arm: perf: conditionally use PERF_PMU_CAP_NO_EXCLUDE
arm: perf/core: use PERF_PMU_CAP_NO_EXCLUDE for exclude incapable PMUs
drivers/perf: perf/core: use PERF_PMU_CAP_NO_EXCLUDE for exclude
incapable PMUs
drivers/perf: perf/core: use PERF_PMU_CAP_NO_EXCLUDE for exclude
incapable PMUs
powerpc: perf/core: use PERF_PMU_CAP_NO_EXCLUDE for exclude incapable
PMUs
x86: perf/core: use PERF_PMU_CAP_NO_EXCLUDE for exclude incapable PMUs
x86: perf/core: use PERF_PMU_CAP_NO_EXCLUDE for exclude incapable PMUs
perf/core: remove unused perf_flags
arch/alpha/kernel/perf_event.c | 7 +------
arch/arm/mach-imx/mmdc.c | 9 ++-------
arch/arm/mm/cache-l2x0-pmu.c | 9 +--------
arch/powerpc/perf/hv-24x7.c | 10 +---------
arch/powerpc/perf/hv-gpci.c | 10 +---------
arch/powerpc/perf/imc-pmu.c | 19 +------------------
arch/x86/events/amd/ibs.c | 13 +------------
arch/x86/events/amd/iommu.c | 6 +-----
arch/x86/events/amd/power.c | 10 ++--------
arch/x86/events/amd/uncore.c | 7 ++-----
arch/x86/events/intel/cstate.c | 12 +++---------
arch/x86/events/intel/rapl.c | 9 ++-------
arch/x86/events/intel/uncore.c | 9 +--------
arch/x86/events/intel/uncore_snb.c | 9 ++-------
arch/x86/events/msr.c | 10 ++--------
drivers/perf/arm-cci.c | 10 +---------
drivers/perf/arm-ccn.c | 6 ++----
drivers/perf/arm_dsu_pmu.c | 9 ++-------
drivers/perf/arm_pmu.c | 15 +++++----------
drivers/perf/hisilicon/hisi_uncore_ddrc_pmu.c | 1 +
drivers/perf/hisilicon/hisi_uncore_hha_pmu.c | 1 +
drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c | 1 +
drivers/perf/hisilicon/hisi_uncore_pmu.c | 9 ---------
drivers/perf/qcom_l2_pmu.c | 9 +--------
drivers/perf/qcom_l3_pmu.c | 8 +-------
drivers/perf/xgene_pmu.c | 6 +-----
include/linux/perf_event.h | 10 ++++++++++
include/uapi/linux/perf_event.h | 2 --
kernel/events/core.c | 9 +++++++++
tools/include/uapi/linux/perf_event.h | 2 --
tools/perf/design.txt | 4 ++++
31 files changed, 62 insertions(+), 189 deletions(-)
--
2.7.4
