struct perf_event_attr supports exclude counting of idle task. This is sent to kernel via perf_event_attr.exclude_idle and in perf tool, user can use ":I" event modifier to enable this for specific event.
Monitor Mode Control Register 2 (MMCR2) SPR has control bits for each PMCs to freeze counting based on the Control Register CTRL[RUN] state. CTRL[RUN] is not set when idle task is running. Patch adds a check for event attr.exclude_idle to set MMCR2[FCnWAIT] bit. Signed-off-by: Madhavan Srinivasan <ma...@linux.ibm.com> --- arch/powerpc/perf/isa207-common.c | 3 +++ arch/powerpc/perf/isa207-common.h | 1 + 2 files changed, 4 insertions(+) diff --git a/arch/powerpc/perf/isa207-common.c b/arch/powerpc/perf/isa207-common.c index e4f577da33d8..5e05f90dd7df 100644 --- a/arch/powerpc/perf/isa207-common.c +++ b/arch/powerpc/perf/isa207-common.c @@ -587,6 +587,9 @@ int isa207_compute_mmcr(u64 event[], int n_ev, mmcr2 |= MMCR2_FCS(pmc); } + if (pevents[i]->attr.exclude_idle) + mmcr2 |= MMCR2_FCWAIT(pmc); + if (cpu_has_feature(CPU_FTR_ARCH_31)) { if (pmc <= 4) { val = (event[i] >> p10_EVENT_MMCR3_SHIFT) & diff --git a/arch/powerpc/perf/isa207-common.h b/arch/powerpc/perf/isa207-common.h index 1af0e8c97ac7..a95a810fa832 100644 --- a/arch/powerpc/perf/isa207-common.h +++ b/arch/powerpc/perf/isa207-common.h @@ -248,6 +248,7 @@ /* Bits in MMCR2 for PowerISA v2.07 */ #define MMCR2_FCS(pmc) (1ull << (63 - (((pmc) - 1) * 9))) #define MMCR2_FCP(pmc) (1ull << (62 - (((pmc) - 1) * 9))) +#define MMCR2_FCWAIT(pmc) (1ull << (58 - (((pmc) - 1) * 9))) #define MMCR2_FCH(pmc) (1ull << (57 - (((pmc) - 1) * 9))) #define MAX_ALT 2 -- 2.26.2