From 1c024eca51fdc965290acf342ae16a476c2189d0 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 19 May 2010 14:02:22 +0200 Subject: perf, trace: Optimize tracepoints by using per-tracepoint-per-cpu hlist to track events Avoid the swevent hash-table by using per-tracepoint hlists. Also, avoid conditionals on the fast path by ordering with probe unregister so that we should never get on the callback path without the data being there. Signed-off-by: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Paul Mackerras Cc: Mike Galbraith Cc: Steven Rostedt LKML-Reference: <20100521090710.473188012@chello.nl> Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 94 +++++++++++++++++++++++++++-------------------------- 1 file changed, 48 insertions(+), 46 deletions(-) (limited to 'kernel/perf_event.c') diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 45b7aec55458..3f2cc313ee25 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -4005,9 +4005,6 @@ static void perf_swevent_add(struct perf_event *event, u64 nr, perf_swevent_overflow(event, 0, nmi, data, regs); } -static int perf_tp_event_match(struct perf_event *event, - struct perf_sample_data *data); - static int perf_exclude_event(struct perf_event *event, struct pt_regs *regs) { @@ -4037,10 +4034,6 @@ static int perf_swevent_match(struct perf_event *event, if (perf_exclude_event(event, regs)) return 0; - if (event->attr.type == PERF_TYPE_TRACEPOINT && - !perf_tp_event_match(event, data)) - return 0; - return 1; } @@ -4122,7 +4115,7 @@ end: int perf_swevent_get_recursion_context(void) { - struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context); + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); int rctx; if (in_nmi()) @@ -4134,10 +4127,8 @@ int perf_swevent_get_recursion_context(void) else rctx = 0; - if (cpuctx->recursion[rctx]) { - put_cpu_var(perf_cpu_context); + if (cpuctx->recursion[rctx]) return -1; - } cpuctx->recursion[rctx]++; barrier(); @@ -4151,7 +4142,6 @@ void perf_swevent_put_recursion_context(int rctx) struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); barrier(); cpuctx->recursion[rctx]--; - put_cpu_var(perf_cpu_context); } EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context); @@ -4162,6 +4152,7 @@ void __perf_sw_event(u32 event_id, u64 nr, int nmi, struct perf_sample_data data; int rctx; + preempt_disable_notrace(); rctx = perf_swevent_get_recursion_context(); if (rctx < 0) return; @@ -4171,6 +4162,7 @@ void __perf_sw_event(u32 event_id, u64 nr, int nmi, do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi, &data, regs); perf_swevent_put_recursion_context(rctx); + preempt_enable_notrace(); } static void perf_swevent_read(struct perf_event *event) @@ -4486,11 +4478,43 @@ static int swevent_hlist_get(struct perf_event *event) #ifdef CONFIG_EVENT_TRACING -void perf_tp_event(int event_id, u64 addr, u64 count, void *record, - int entry_size, struct pt_regs *regs, void *event) +static const struct pmu perf_ops_tracepoint = { + .enable = perf_trace_enable, + .disable = perf_trace_disable, + .read = perf_swevent_read, + .unthrottle = perf_swevent_unthrottle, +}; + +static int perf_tp_filter_match(struct perf_event *event, + struct perf_sample_data *data) +{ + void *record = data->raw->data; + + if (likely(!event->filter) || filter_match_preds(event->filter, record)) + return 1; + return 0; +} + +static int perf_tp_event_match(struct perf_event *event, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + if (perf_exclude_event(event, regs)) + return 0; + + if (!perf_tp_filter_match(event, data)) + return 0; + + return 1; +} + +void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, + struct pt_regs *regs, struct hlist_head *head) { - const int type = PERF_TYPE_TRACEPOINT; struct perf_sample_data data; + struct perf_event *event; + struct hlist_node *node; + struct perf_raw_record raw = { .size = entry_size, .data = record, @@ -4499,30 +4523,18 @@ void perf_tp_event(int event_id, u64 addr, u64 count, void *record, perf_sample_data_init(&data, addr); data.raw = &raw; - if (!event) { - do_perf_sw_event(type, event_id, count, 1, &data, regs); - return; + rcu_read_lock(); + 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); } - - if (perf_swevent_match(event, type, event_id, &data, regs)) - perf_swevent_add(event, count, 1, &data, regs); + rcu_read_unlock(); } EXPORT_SYMBOL_GPL(perf_tp_event); -static int perf_tp_event_match(struct perf_event *event, - struct perf_sample_data *data) -{ - void *record = data->raw->data; - - if (likely(!event->filter) || filter_match_preds(event->filter, record)) - return 1; - return 0; -} - static void tp_perf_event_destroy(struct perf_event *event) { - perf_trace_disable(event->attr.config); - swevent_hlist_put(event); + perf_trace_destroy(event); } static const struct pmu *tp_perf_event_init(struct perf_event *event) @@ -4538,17 +4550,13 @@ static const struct pmu *tp_perf_event_init(struct perf_event *event) !capable(CAP_SYS_ADMIN)) return ERR_PTR(-EPERM); - if (perf_trace_enable(event->attr.config, event)) + err = perf_trace_init(event); + if (err) return NULL; event->destroy = tp_perf_event_destroy; - err = swevent_hlist_get(event); - if (err) { - perf_trace_disable(event->attr.config); - return ERR_PTR(err); - } - return &perf_ops_generic; + return &perf_ops_tracepoint; } static int perf_event_set_filter(struct perf_event *event, void __user *arg) @@ -4576,12 +4584,6 @@ static void perf_event_free_filter(struct perf_event *event) #else -static int perf_tp_event_match(struct perf_event *event, - struct perf_sample_data *data) -{ - return 1; -} - static const struct pmu *tp_perf_event_init(struct perf_event *event) { return NULL; -- cgit v1.2.3