Messages in this thread Patch in this message |  | | Date | Tue, 21 Oct 2014 11:14:34 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC 5/5] x86,perf: Only allow rdpmc if a perf_event is mapped |
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On Mon, Oct 20, 2014 at 12:51:10PM +0200, Hendrik Brueckner wrote: > I think it would makes sense to return 0 as default in the > perf_event_idx_default() and let each PMU/arch that actually supports > reading PMCs from user space return the proper index. And according > to tools/perf/design.txt, index must be non-zero to trigger a user space > read.
OK, I've got something like the below. Michael/Anton, would you please clarify the ppc book3s capabilities?
--- Subject: perf: Clean up pmu::event_idx From: Peter Zijlstra <peterz@infradead.org> Date: Tue Oct 21 11:10:21 CEST 2014
Andy reported that the current state of event_idx is rather confused. So remove all but the x86_pmu implementation and change the default to return 0 (the safe option).
Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- arch/powerpc/perf/hv-24x7.c | 6 ------ arch/powerpc/perf/hv-gpci.c | 6 ------ arch/s390/kernel/perf_cpum_sf.c | 6 ------ kernel/events/core.c | 15 +-------------- kernel/events/hw_breakpoint.c | 7 ------- 5 files changed, 1 insertion(+), 39 deletions(-)
--- a/arch/powerpc/perf/hv-24x7.c +++ b/arch/powerpc/perf/hv-24x7.c @@ -417,11 +417,6 @@ static int h_24x7_event_add(struct perf_ return 0; } -static int h_24x7_event_idx(struct perf_event *event) -{ - return 0; -} - static struct pmu h_24x7_pmu = { .task_ctx_nr = perf_invalid_context, @@ -433,7 +428,6 @@ static struct pmu h_24x7_pmu = { .start = h_24x7_event_start, .stop = h_24x7_event_stop, .read = h_24x7_event_update, - .event_idx = h_24x7_event_idx, }; static int hv_24x7_init(void) --- a/arch/powerpc/perf/hv-gpci.c +++ b/arch/powerpc/perf/hv-gpci.c @@ -246,11 +246,6 @@ static int h_gpci_event_init(struct perf return 0; } -static int h_gpci_event_idx(struct perf_event *event) -{ - return 0; -} - static struct pmu h_gpci_pmu = { .task_ctx_nr = perf_invalid_context, @@ -262,7 +257,6 @@ static struct pmu h_gpci_pmu = { .start = h_gpci_event_start, .stop = h_gpci_event_stop, .read = h_gpci_event_update, - .event_idx = h_gpci_event_idx, }; static int hv_gpci_init(void) --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -1411,11 +1411,6 @@ static void cpumsf_pmu_del(struct perf_e perf_pmu_enable(event->pmu); } -static int cpumsf_pmu_event_idx(struct perf_event *event) -{ - return event->hw.idx; -} - CPUMF_EVENT_ATTR(SF, SF_CYCLES_BASIC, PERF_EVENT_CPUM_SF); CPUMF_EVENT_ATTR(SF, SF_CYCLES_BASIC_DIAG, PERF_EVENT_CPUM_SF_DIAG); @@ -1458,7 +1453,6 @@ static struct pmu cpumf_sampling = { .stop = cpumsf_pmu_stop, .read = cpumsf_pmu_read, - .event_idx = cpumsf_pmu_event_idx, .attr_groups = cpumsf_pmu_attr_groups, }; --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6071,11 +6071,6 @@ static int perf_swevent_init(struct perf return 0; } -static int perf_swevent_event_idx(struct perf_event *event) -{ - return 0; -} - static struct pmu perf_swevent = { .task_ctx_nr = perf_sw_context, @@ -6085,8 +6080,6 @@ static struct pmu perf_swevent = { .start = perf_swevent_start, .stop = perf_swevent_stop, .read = perf_swevent_read, - - .event_idx = perf_swevent_event_idx, }; #ifdef CONFIG_EVENT_TRACING @@ -6204,8 +6197,6 @@ static struct pmu perf_tracepoint = { .start = perf_swevent_start, .stop = perf_swevent_stop, .read = perf_swevent_read, - - .event_idx = perf_swevent_event_idx, }; static inline void perf_tp_register(void) @@ -6431,8 +6422,6 @@ static struct pmu perf_cpu_clock = { .start = cpu_clock_event_start, .stop = cpu_clock_event_stop, .read = cpu_clock_event_read, - - .event_idx = perf_swevent_event_idx, }; /* @@ -6511,8 +6500,6 @@ static struct pmu perf_task_clock = { .start = task_clock_event_start, .stop = task_clock_event_stop, .read = task_clock_event_read, - - .event_idx = perf_swevent_event_idx, }; static void perf_pmu_nop_void(struct pmu *pmu) @@ -6542,7 +6529,7 @@ static void perf_pmu_cancel_txn(struct p static int perf_event_idx_default(struct perf_event *event) { - return event->hw.idx + 1; + return 0; } /* --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -605,11 +605,6 @@ static void hw_breakpoint_stop(struct pe bp->hw.state = PERF_HES_STOPPED; } -static int hw_breakpoint_event_idx(struct perf_event *bp) -{ - return 0; -} - static struct pmu perf_breakpoint = { .task_ctx_nr = perf_sw_context, /* could eventually get its own */ @@ -619,8 +614,6 @@ static struct pmu perf_breakpoint = { .start = hw_breakpoint_start, .stop = hw_breakpoint_stop, .read = hw_breakpoint_pmu_read, - - .event_idx = hw_breakpoint_event_idx, }; int __init init_hw_breakpoint(void)
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