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author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2010-06-16 14:37:10 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2010-09-09 20:46:30 +0200 |
commit | a4eaf7f14675cb512d69f0c928055e73d0c6d252 (patch) | |
tree | e8a0f631fc28d4bd9becd2e9e2c71743c64ee3ec /kernel | |
parent | fa407f35e0298d841e4088f95a7f9cf6e725c6d5 (diff) | |
download | linux-stable-a4eaf7f14675cb512d69f0c928055e73d0c6d252.tar.gz linux-stable-a4eaf7f14675cb512d69f0c928055e73d0c6d252.tar.bz2 linux-stable-a4eaf7f14675cb512d69f0c928055e73d0c6d252.zip |
perf: Rework the PMU methods
Replace pmu::{enable,disable,start,stop,unthrottle} with
pmu::{add,del,start,stop}, all of which take a flags argument.
The new interface extends the capability to stop a counter while
keeping it scheduled on the PMU. We replace the throttled state with
the generic stopped state.
This also allows us to efficiently stop/start counters over certain
code paths (like IRQ handlers).
It also allows scheduling a counter without it starting, allowing for
a generic frozen state (useful for rotating stopped counters).
The stopped state is implemented in two different ways, depending on
how the architecture implemented the throttled state:
1) We disable the counter:
a) the pmu has per-counter enable bits, we flip that
b) we program a NOP event, preserving the counter state
2) We store the counter state and ignore all read/overflow events
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus <paulus@samba.org>
Cc: stephane eranian <eranian@googlemail.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Yanmin <yanmin_zhang@linux.intel.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: Michael Cree <mcree@orcon.net.nz>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/hw_breakpoint.c | 29 | ||||
-rw-r--r-- | kernel/perf_event.c | 140 | ||||
-rw-r--r-- | kernel/trace/trace_event_perf.c | 7 |
3 files changed, 104 insertions, 72 deletions
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c index e9c5cfa1fd20..6f150095cafe 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/hw_breakpoint.c @@ -586,10 +586,35 @@ static int hw_breakpoint_event_init(struct perf_event *bp) return 0; } +static int hw_breakpoint_add(struct perf_event *bp, int flags) +{ + if (!(flags & PERF_EF_START)) + bp->hw.state = PERF_HES_STOPPED; + + return arch_install_hw_breakpoint(bp); +} + +static void hw_breakpoint_del(struct perf_event *bp, int flags) +{ + arch_uninstall_hw_breakpoint(bp); +} + +static void hw_breakpoint_start(struct perf_event *bp, int flags) +{ + bp->hw.state = 0; +} + +static void hw_breakpoint_stop(struct perf_event *bp, int flags) +{ + bp->hw.state = PERF_HES_STOPPED; +} + static struct pmu perf_breakpoint = { .event_init = hw_breakpoint_event_init, - .enable = arch_install_hw_breakpoint, - .disable = arch_uninstall_hw_breakpoint, + .add = hw_breakpoint_add, + .del = hw_breakpoint_del, + .start = hw_breakpoint_start, + .stop = hw_breakpoint_stop, .read = hw_breakpoint_pmu_read, }; diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 1a6cdbf0d091..3bace4fd0355 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -424,7 +424,7 @@ event_sched_out(struct perf_event *event, event->state = PERF_EVENT_STATE_OFF; } event->tstamp_stopped = ctx->time; - event->pmu->disable(event); + event->pmu->del(event, 0); event->oncpu = -1; if (!is_software_event(event)) @@ -649,7 +649,7 @@ event_sched_in(struct perf_event *event, */ smp_wmb(); - if (event->pmu->enable(event)) { + if (event->pmu->add(event, PERF_EF_START)) { event->state = PERF_EVENT_STATE_INACTIVE; event->oncpu = -1; return -EAGAIN; @@ -1482,22 +1482,6 @@ do { \ return div64_u64(dividend, divisor); } -static void perf_event_stop(struct perf_event *event) -{ - if (!event->pmu->stop) - return event->pmu->disable(event); - - return event->pmu->stop(event); -} - -static int perf_event_start(struct perf_event *event) -{ - if (!event->pmu->start) - return event->pmu->enable(event); - - return event->pmu->start(event); -} - static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count) { struct hw_perf_event *hwc = &event->hw; @@ -1517,9 +1501,9 @@ static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count) hwc->sample_period = sample_period; if (local64_read(&hwc->period_left) > 8*sample_period) { - perf_event_stop(event); + event->pmu->stop(event, PERF_EF_UPDATE); local64_set(&hwc->period_left, 0); - perf_event_start(event); + event->pmu->start(event, PERF_EF_RELOAD); } } @@ -1548,7 +1532,7 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx) */ if (interrupts == MAX_INTERRUPTS) { perf_log_throttle(event, 1); - event->pmu->unthrottle(event); + event->pmu->start(event, 0); } if (!event->attr.freq || !event->attr.sample_freq) @@ -2506,6 +2490,9 @@ int perf_event_task_disable(void) static int perf_event_index(struct perf_event *event) { + if (event->hw.state & PERF_HES_STOPPED) + return 0; + if (event->state != PERF_EVENT_STATE_ACTIVE) return 0; @@ -4120,8 +4107,6 @@ static int __perf_event_overflow(struct perf_event *event, int nmi, struct hw_perf_event *hwc = &event->hw; int ret = 0; - throttle = (throttle && event->pmu->unthrottle != NULL); - if (!throttle) { hwc->interrupts++; } else { @@ -4246,7 +4231,7 @@ static void perf_swevent_overflow(struct perf_event *event, u64 overflow, } } -static void perf_swevent_add(struct perf_event *event, u64 nr, +static void perf_swevent_event(struct perf_event *event, u64 nr, int nmi, struct perf_sample_data *data, struct pt_regs *regs) { @@ -4272,6 +4257,9 @@ static void perf_swevent_add(struct perf_event *event, u64 nr, static int perf_exclude_event(struct perf_event *event, struct pt_regs *regs) { + if (event->hw.state & PERF_HES_STOPPED) + return 0; + if (regs) { if (event->attr.exclude_user && user_mode(regs)) return 1; @@ -4371,7 +4359,7 @@ static void do_perf_sw_event(enum perf_type_id type, u32 event_id, hlist_for_each_entry_rcu(event, node, head, hlist_entry) { if (perf_swevent_match(event, type, event_id, data, regs)) - perf_swevent_add(event, nr, nmi, data, regs); + perf_swevent_event(event, nr, nmi, data, regs); } end: rcu_read_unlock(); @@ -4415,7 +4403,7 @@ static void perf_swevent_read(struct perf_event *event) { } -static int perf_swevent_enable(struct perf_event *event) +static int perf_swevent_add(struct perf_event *event, int flags) { struct hw_perf_event *hwc = &event->hw; struct perf_cpu_context *cpuctx; @@ -4428,6 +4416,8 @@ static int perf_swevent_enable(struct perf_event *event) perf_swevent_set_period(event); } + hwc->state = !(flags & PERF_EF_START); + head = find_swevent_head(cpuctx, event); if (WARN_ON_ONCE(!head)) return -EINVAL; @@ -4437,18 +4427,19 @@ static int perf_swevent_enable(struct perf_event *event) return 0; } -static void perf_swevent_disable(struct perf_event *event) +static void perf_swevent_del(struct perf_event *event, int flags) { hlist_del_rcu(&event->hlist_entry); } -static void perf_swevent_void(struct perf_event *event) +static void perf_swevent_start(struct perf_event *event, int flags) { + event->hw.state = 0; } -static int perf_swevent_int(struct perf_event *event) +static void perf_swevent_stop(struct perf_event *event, int flags) { - return 0; + event->hw.state = PERF_HES_STOPPED; } /* Deref the hlist from the update side */ @@ -4604,12 +4595,11 @@ static int perf_swevent_init(struct perf_event *event) static struct pmu perf_swevent = { .event_init = perf_swevent_init, - .enable = perf_swevent_enable, - .disable = perf_swevent_disable, - .start = perf_swevent_int, - .stop = perf_swevent_void, + .add = perf_swevent_add, + .del = perf_swevent_del, + .start = perf_swevent_start, + .stop = perf_swevent_stop, .read = perf_swevent_read, - .unthrottle = perf_swevent_void, /* hwc->interrupts already reset */ }; #ifdef CONFIG_EVENT_TRACING @@ -4657,7 +4647,7 @@ void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, hlist_for_each_entry_rcu(event, node, head, hlist_entry) { if (perf_tp_event_match(event, &data, regs)) - perf_swevent_add(event, count, 1, &data, regs); + perf_swevent_event(event, count, 1, &data, regs); } perf_swevent_put_recursion_context(rctx); @@ -4696,12 +4686,11 @@ static int perf_tp_event_init(struct perf_event *event) static struct pmu perf_tracepoint = { .event_init = perf_tp_event_init, - .enable = perf_trace_enable, - .disable = perf_trace_disable, - .start = perf_swevent_int, - .stop = perf_swevent_void, + .add = perf_trace_add, + .del = perf_trace_del, + .start = perf_swevent_start, + .stop = perf_swevent_stop, .read = perf_swevent_read, - .unthrottle = perf_swevent_void, }; static inline void perf_tp_register(void) @@ -4757,8 +4746,8 @@ void perf_bp_event(struct perf_event *bp, void *data) perf_sample_data_init(&sample, bp->attr.bp_addr); - if (!perf_exclude_event(bp, regs)) - perf_swevent_add(bp, 1, 1, &sample, regs); + if (!bp->hw.state && !perf_exclude_event(bp, regs)) + perf_swevent_event(bp, 1, 1, &sample, regs); } #endif @@ -4834,32 +4823,39 @@ static void perf_swevent_cancel_hrtimer(struct perf_event *event) static void cpu_clock_event_update(struct perf_event *event) { - int cpu = raw_smp_processor_id(); s64 prev; u64 now; - now = cpu_clock(cpu); + now = local_clock(); prev = local64_xchg(&event->hw.prev_count, now); local64_add(now - prev, &event->count); } -static int cpu_clock_event_enable(struct perf_event *event) +static void cpu_clock_event_start(struct perf_event *event, int flags) { - struct hw_perf_event *hwc = &event->hw; - int cpu = raw_smp_processor_id(); - - local64_set(&hwc->prev_count, cpu_clock(cpu)); + local64_set(&event->hw.prev_count, local_clock()); perf_swevent_start_hrtimer(event); - - return 0; } -static void cpu_clock_event_disable(struct perf_event *event) +static void cpu_clock_event_stop(struct perf_event *event, int flags) { perf_swevent_cancel_hrtimer(event); cpu_clock_event_update(event); } +static int cpu_clock_event_add(struct perf_event *event, int flags) +{ + if (flags & PERF_EF_START) + cpu_clock_event_start(event, flags); + + return 0; +} + +static void cpu_clock_event_del(struct perf_event *event, int flags) +{ + cpu_clock_event_stop(event, flags); +} + static void cpu_clock_event_read(struct perf_event *event) { cpu_clock_event_update(event); @@ -4878,8 +4874,10 @@ static int cpu_clock_event_init(struct perf_event *event) static struct pmu perf_cpu_clock = { .event_init = cpu_clock_event_init, - .enable = cpu_clock_event_enable, - .disable = cpu_clock_event_disable, + .add = cpu_clock_event_add, + .del = cpu_clock_event_del, + .start = cpu_clock_event_start, + .stop = cpu_clock_event_stop, .read = cpu_clock_event_read, }; @@ -4897,25 +4895,29 @@ static void task_clock_event_update(struct perf_event *event, u64 now) local64_add(delta, &event->count); } -static int task_clock_event_enable(struct perf_event *event) +static void task_clock_event_start(struct perf_event *event, int flags) { - struct hw_perf_event *hwc = &event->hw; - u64 now; - - now = event->ctx->time; - - local64_set(&hwc->prev_count, now); - + local64_set(&event->hw.prev_count, event->ctx->time); perf_swevent_start_hrtimer(event); - - return 0; } -static void task_clock_event_disable(struct perf_event *event) +static void task_clock_event_stop(struct perf_event *event, int flags) { perf_swevent_cancel_hrtimer(event); task_clock_event_update(event, event->ctx->time); +} + +static int task_clock_event_add(struct perf_event *event, int flags) +{ + if (flags & PERF_EF_START) + task_clock_event_start(event, flags); + return 0; +} + +static void task_clock_event_del(struct perf_event *event, int flags) +{ + task_clock_event_stop(event, PERF_EF_UPDATE); } static void task_clock_event_read(struct perf_event *event) @@ -4947,8 +4949,10 @@ static int task_clock_event_init(struct perf_event *event) static struct pmu perf_task_clock = { .event_init = task_clock_event_init, - .enable = task_clock_event_enable, - .disable = task_clock_event_disable, + .add = task_clock_event_add, + .del = task_clock_event_del, + .start = task_clock_event_start, + .stop = task_clock_event_stop, .read = task_clock_event_read, }; diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index f3bbcd1c90c8..39c059ca670e 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -101,7 +101,7 @@ int perf_trace_init(struct perf_event *p_event) return ret; } -int perf_trace_enable(struct perf_event *p_event) +int perf_trace_add(struct perf_event *p_event, int flags) { struct ftrace_event_call *tp_event = p_event->tp_event; struct hlist_head __percpu *pcpu_list; @@ -111,13 +111,16 @@ int perf_trace_enable(struct perf_event *p_event) if (WARN_ON_ONCE(!pcpu_list)) return -EINVAL; + if (!(flags & PERF_EF_START)) + p_event->hw.state = PERF_HES_STOPPED; + list = this_cpu_ptr(pcpu_list); hlist_add_head_rcu(&p_event->hlist_entry, list); return 0; } -void perf_trace_disable(struct perf_event *p_event) +void perf_trace_del(struct perf_event *p_event, int flags) { hlist_del_rcu(&p_event->hlist_entry); } |