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perf: Dynamic pmu types
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Extend the perf_pmu_register() interface to allow for named and
dynamic pmu types.

Because we need to support the existing static types we cannot use
dynamic types for everything, hence provide a type argument.

If we want to enumerate the PMUs they need a name, provide one.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101117222056.259707703@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Peter Zijlstra authored and Ingo Molnar committed Dec 16, 2010
1 parent 9f58a20 commit 2e80a82
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Showing 10 changed files with 54 additions and 15 deletions.
2 changes: 1 addition & 1 deletion arch/alpha/kernel/perf_event.c
Original file line number Diff line number Diff line change
Expand Up @@ -882,7 +882,7 @@ int __init init_hw_perf_events(void)
/* And set up PMU specification */
alpha_pmu = &ev67_pmu;

perf_pmu_register(&pmu);
perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);

return 0;
}
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2 changes: 1 addition & 1 deletion arch/arm/kernel/perf_event.c
Original file line number Diff line number Diff line change
Expand Up @@ -3034,7 +3034,7 @@ init_hw_perf_events(void)
pr_info("no hardware support available\n");
}

perf_pmu_register(&pmu);
perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);

return 0;
}
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2 changes: 1 addition & 1 deletion arch/powerpc/kernel/perf_event.c
Original file line number Diff line number Diff line change
Expand Up @@ -1379,7 +1379,7 @@ int register_power_pmu(struct power_pmu *pmu)
freeze_events_kernel = MMCR0_FCHV;
#endif /* CONFIG_PPC64 */

perf_pmu_register(&power_pmu);
perf_pmu_register(&power_pmu, "cpu", PERF_TYPE_RAW);
perf_cpu_notifier(power_pmu_notifier);

return 0;
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2 changes: 1 addition & 1 deletion arch/powerpc/kernel/perf_event_fsl_emb.c
Original file line number Diff line number Diff line change
Expand Up @@ -681,7 +681,7 @@ int register_fsl_emb_pmu(struct fsl_emb_pmu *pmu)
pr_info("%s performance monitor hardware support registered\n",
pmu->name);

perf_pmu_register(&fsl_emb_pmu);
perf_pmu_register(&fsl_emb_pmu, "cpu", PERF_TYPE_RAW);

return 0;
}
2 changes: 1 addition & 1 deletion arch/sh/kernel/perf_event.c
Original file line number Diff line number Diff line change
Expand Up @@ -389,7 +389,7 @@ int __cpuinit register_sh_pmu(struct sh_pmu *_pmu)

WARN_ON(_pmu->num_events > MAX_HWEVENTS);

perf_pmu_register(&pmu);
perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
perf_cpu_notifier(sh_pmu_notifier);
return 0;
}
2 changes: 1 addition & 1 deletion arch/sparc/kernel/perf_event.c
Original file line number Diff line number Diff line change
Expand Up @@ -1318,7 +1318,7 @@ int __init init_hw_perf_events(void)

pr_cont("Supported PMU type is '%s'\n", sparc_pmu_type);

perf_pmu_register(&pmu);
perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
register_die_notifier(&perf_event_nmi_notifier);

return 0;
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2 changes: 1 addition & 1 deletion arch/x86/kernel/cpu/perf_event.c
Original file line number Diff line number Diff line change
Expand Up @@ -1465,7 +1465,7 @@ int __init init_hw_perf_events(void)
pr_info("... fixed-purpose events: %d\n", x86_pmu.num_counters_fixed);
pr_info("... event mask: %016Lx\n", x86_pmu.intel_ctrl);

perf_pmu_register(&pmu);
perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
perf_cpu_notifier(x86_pmu_notifier);

return 0;
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5 changes: 4 additions & 1 deletion include/linux/perf_event.h
Original file line number Diff line number Diff line change
Expand Up @@ -588,6 +588,9 @@ struct perf_event;
struct pmu {
struct list_head entry;

char *name;
int type;

int * __percpu pmu_disable_count;
struct perf_cpu_context * __percpu pmu_cpu_context;
int task_ctx_nr;
Expand Down Expand Up @@ -916,7 +919,7 @@ struct perf_output_handle {

#ifdef CONFIG_PERF_EVENTS

extern int perf_pmu_register(struct pmu *pmu);
extern int perf_pmu_register(struct pmu *pmu, char *name, int type);
extern void perf_pmu_unregister(struct pmu *pmu);

extern int perf_num_counters(void);
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2 changes: 1 addition & 1 deletion kernel/hw_breakpoint.c
Original file line number Diff line number Diff line change
Expand Up @@ -641,7 +641,7 @@ int __init init_hw_breakpoint(void)

constraints_initialized = 1;

perf_pmu_register(&perf_breakpoint);
perf_pmu_register(&perf_breakpoint, "breakpoint", PERF_TYPE_BREAKPOINT);

return register_die_notifier(&hw_breakpoint_exceptions_nb);

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48 changes: 42 additions & 6 deletions kernel/perf_event.c
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@
#include <linux/mm.h>
#include <linux/cpu.h>
#include <linux/smp.h>
#include <linux/idr.h>
#include <linux/file.h>
#include <linux/poll.h>
#include <linux/slab.h>
Expand Down Expand Up @@ -4961,7 +4962,7 @@ static struct pmu perf_tracepoint = {

static inline void perf_tp_register(void)
{
perf_pmu_register(&perf_tracepoint);
perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT);
}

static int perf_event_set_filter(struct perf_event *event, void __user *arg)
Expand Down Expand Up @@ -5305,8 +5306,9 @@ static void free_pmu_context(struct pmu *pmu)
out:
mutex_unlock(&pmus_lock);
}
static struct idr pmu_idr;

int perf_pmu_register(struct pmu *pmu)
int perf_pmu_register(struct pmu *pmu, char *name, int type)
{
int cpu, ret;

Expand All @@ -5316,13 +5318,32 @@ int perf_pmu_register(struct pmu *pmu)
if (!pmu->pmu_disable_count)
goto unlock;

pmu->type = -1;
if (!name)
goto skip_type;
pmu->name = name;

if (type < 0) {
int err = idr_pre_get(&pmu_idr, GFP_KERNEL);
if (!err)
goto free_pdc;

err = idr_get_new_above(&pmu_idr, pmu, PERF_TYPE_MAX, &type);
if (err) {
ret = err;
goto free_pdc;
}
}
pmu->type = type;

skip_type:
pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr);
if (pmu->pmu_cpu_context)
goto got_cpu_context;

pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context);
if (!pmu->pmu_cpu_context)
goto free_pdc;
goto free_ird;

for_each_possible_cpu(cpu) {
struct perf_cpu_context *cpuctx;
Expand Down Expand Up @@ -5366,6 +5387,10 @@ int perf_pmu_register(struct pmu *pmu)

return ret;

free_idr:
if (pmu->type >= PERF_TYPE_MAX)
idr_remove(&pmu_idr, pmu->type);

free_pdc:
free_percpu(pmu->pmu_disable_count);
goto unlock;
Expand All @@ -5385,6 +5410,8 @@ void perf_pmu_unregister(struct pmu *pmu)
synchronize_rcu();

free_percpu(pmu->pmu_disable_count);
if (pmu->type >= PERF_TYPE_MAX)
idr_remove(&pmu_idr, pmu->type);
free_pmu_context(pmu);
}

Expand All @@ -5394,6 +5421,13 @@ struct pmu *perf_init_event(struct perf_event *event)
int idx;

idx = srcu_read_lock(&pmus_srcu);

rcu_read_lock();
pmu = idr_find(&pmu_idr, event->attr.type);
rcu_read_unlock();
if (pmu)
goto unlock;

list_for_each_entry_rcu(pmu, &pmus, entry) {
int ret = pmu->event_init(event);
if (!ret)
Expand Down Expand Up @@ -6555,11 +6589,13 @@ void __init perf_event_init(void)
{
int ret;

idr_init(&pmu_idr);

perf_event_init_all_cpus();
init_srcu_struct(&pmus_srcu);
perf_pmu_register(&perf_swevent);
perf_pmu_register(&perf_cpu_clock);
perf_pmu_register(&perf_task_clock);
perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE);
perf_pmu_register(&perf_cpu_clock, NULL, -1);
perf_pmu_register(&perf_task_clock, NULL, -1);
perf_tp_register();
perf_cpu_notifier(perf_cpu_notify);
register_reboot_notifier(&perf_reboot_notifier);
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