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 ability to exclude
based on context via a new capability: PERF_PMU_CAP_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 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 (20):
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_EXCLUDE for exclusion capable PMUs
perf/hw_breakpoint: perf/core: advertise PMU exclusion capability
alpha: perf/core: remove unnecessary checks for exclusion
arc: perf/core: advertise PMU exclusion capability
arm: perf: conditionally advertise PMU exclusion capability
arm: perf/core: remove unnecessary checks for exclusion
drivers/perf: perf/core: remove unnecessary checks for exclusion
drivers/perf: perf/core: remove unnecessary checks for exclusion
drivers/perf: perf/core: advertise PMU exclusion capability
mips: perf/core: advertise PMU exclusion capability
powerpc: perf/core: advertise PMU exclusion capability
powerpc: perf/core: remove unnecessary checks for exclusion
s390: perf/events: advertise PMU exclusion capability
sparc: perf/core: advertise PMU exclusion capability
x86: perf/core: remove unnecessary checks for exclusion
x86: perf/core remove unnecessary checks for exclusion
x86: perf/core: advertise PMU exclusion capability
perf/core: remove unused perf_flags
arch/alpha/kernel/perf_event.c | 6 ------
arch/arc/kernel/perf_event.c | 1 +
arch/arm/mach-imx/mmdc.c | 8 +-------
arch/arm/mm/cache-l2x0-pmu.c | 8 --------
arch/mips/kernel/perf_event_mipsxx.c | 1 +
arch/powerpc/perf/core-book3s.c | 1 +
arch/powerpc/perf/core-fsl-emb.c | 1 +
arch/powerpc/perf/hv-24x7.c | 9 ---------
arch/powerpc/perf/hv-gpci.c | 9 ---------
arch/powerpc/perf/imc-pmu.c | 18 ------------------
arch/s390/kernel/perf_cpum_cf.c | 1 +
arch/s390/kernel/perf_cpum_sf.c | 2 ++
arch/sparc/kernel/perf_event.c | 1 +
arch/x86/events/amd/ibs.c | 12 ------------
arch/x86/events/amd/iommu.c | 5 -----
arch/x86/events/amd/power.c | 9 +--------
arch/x86/events/amd/uncore.c | 5 -----
arch/x86/events/core.c | 2 ++
arch/x86/events/intel/bts.c | 2 +-
arch/x86/events/intel/cstate.c | 8 +-------
arch/x86/events/intel/pt.c | 4 +++-
arch/x86/events/intel/rapl.c | 8 +-------
arch/x86/events/intel/uncore.c | 8 --------
arch/x86/events/intel/uncore_snb.c | 8 +-------
arch/x86/events/msr.c | 8 +-------
drivers/perf/arm-cci.c | 9 ---------
drivers/perf/arm-ccn.c | 5 +----
drivers/perf/arm_dsu_pmu.c | 8 +-------
drivers/perf/arm_pmu.c | 15 +++++----------
drivers/perf/arm_spe_pmu.c | 3 ++-
drivers/perf/hisilicon/hisi_uncore_pmu.c | 9 ---------
drivers/perf/qcom_l2_pmu.c | 8 --------
drivers/perf/qcom_l3_pmu.c | 7 -------
drivers/perf/xgene_pmu.c | 5 -----
include/linux/perf_event.h | 10 ++++++++++
include/uapi/linux/perf_event.h | 2 --
kernel/events/core.c | 9 +++++++++
kernel/events/hw_breakpoint.c | 2 ++
tools/include/uapi/linux/perf_event.h | 2 --
tools/perf/design.txt | 4 ++++
40 files changed, 54 insertions(+), 189 deletions(-)
--
2.7.4
