From 571f97f7d51fa81e6cc0e00f0f6314792ce533a3 Mon Sep 17 00:00:00 2001 From: Ravi Bangoria Date: Mon, 10 Oct 2022 12:17:50 +0200 Subject: perf: Optimize perf_tp_event() Use the event group trees to iterate only perf_tracepoint events. Signed-off-by: Ravi Bangoria --- kernel/events/core.c | 134 ++++++++++++++++++++++++++++++--------------------- 1 file changed, 79 insertions(+), 55 deletions(-) (limited to 'kernel/events/core.c') diff --git a/kernel/events/core.c b/kernel/events/core.c index 640f0a50e13b..ec2abc52c887 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9944,6 +9944,44 @@ static struct pmu perf_swevent = { #ifdef CONFIG_EVENT_TRACING +static void tp_perf_event_destroy(struct perf_event *event) +{ + perf_trace_destroy(event); +} + +static int perf_tp_event_init(struct perf_event *event) +{ + int err; + + if (event->attr.type != PERF_TYPE_TRACEPOINT) + return -ENOENT; + + /* + * no branch sampling for tracepoint events + */ + if (has_branch_stack(event)) + return -EOPNOTSUPP; + + err = perf_trace_init(event); + if (err) + return err; + + event->destroy = tp_perf_event_destroy; + + return 0; +} + +static struct pmu perf_tracepoint = { + .task_ctx_nr = perf_sw_context, + + .event_init = perf_tp_event_init, + .add = perf_trace_add, + .del = perf_trace_del, + .start = perf_swevent_start, + .stop = perf_swevent_stop, + .read = perf_swevent_read, +}; + static int perf_tp_filter_match(struct perf_event *event, struct perf_sample_data *data) { @@ -9993,6 +10031,44 @@ void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx, } EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit); +static void __perf_tp_event_target_task(u64 count, void *record, + struct pt_regs *regs, + struct perf_sample_data *data, + struct perf_event *event) +{ + struct trace_entry *entry = record; + + if (event->attr.config != entry->type) + return; + /* Cannot deliver synchronous signal to other task. */ + if (event->attr.sigtrap) + return; + if (perf_tp_event_match(event, data, regs)) + perf_swevent_event(event, count, data, regs); +} + +static void perf_tp_event_target_task(u64 count, void *record, + struct pt_regs *regs, + struct perf_sample_data *data, + struct perf_event_context *ctx) +{ + unsigned int cpu = smp_processor_id(); + struct pmu *pmu = &perf_tracepoint; + struct perf_event *event, *sibling; + + perf_event_groups_for_cpu_pmu(event, &ctx->pinned_groups, cpu, pmu) { + __perf_tp_event_target_task(count, record, regs, data, event); + for_each_sibling_event(sibling, event) + __perf_tp_event_target_task(count, record, regs, data, sibling); + } + + perf_event_groups_for_cpu_pmu(event, &ctx->flexible_groups, cpu, pmu) { + __perf_tp_event_target_task(count, record, regs, data, event); + for_each_sibling_event(sibling, event) + __perf_tp_event_target_task(count, record, regs, data, sibling); + } +} + void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size, struct pt_regs *regs, struct hlist_head *head, int rctx, struct task_struct *task) @@ -10023,29 +10099,15 @@ void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size, */ if (task && task != current) { struct perf_event_context *ctx; - struct trace_entry *entry = record; rcu_read_lock(); ctx = rcu_dereference(task->perf_event_ctxp); if (!ctx) goto unlock; - // XXX iterate groups instead, we should be able to - // find the subtree for the perf_tracepoint pmu and CPU. - - list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { - if (event->cpu != smp_processor_id()) - continue; - if (event->attr.type != PERF_TYPE_TRACEPOINT) - continue; - if (event->attr.config != entry->type) - continue; - /* Cannot deliver synchronous signal to other task. */ - if (event->attr.sigtrap) - continue; - if (perf_tp_event_match(event, &data, regs)) - perf_swevent_event(event, count, &data, regs); - } + raw_spin_lock(&ctx->lock); + perf_tp_event_target_task(count, record, regs, &data, ctx); + raw_spin_unlock(&ctx->lock); unlock: rcu_read_unlock(); } @@ -10054,44 +10116,6 @@ unlock: } EXPORT_SYMBOL_GPL(perf_tp_event); -static void tp_perf_event_destroy(struct perf_event *event) -{ - perf_trace_destroy(event); -} - -static int perf_tp_event_init(struct perf_event *event) -{ - int err; - - if (event->attr.type != PERF_TYPE_TRACEPOINT) - return -ENOENT; - - /* - * no branch sampling for tracepoint events - */ - if (has_branch_stack(event)) - return -EOPNOTSUPP; - - err = perf_trace_init(event); - if (err) - return err; - - event->destroy = tp_perf_event_destroy; - - return 0; -} - -static struct pmu perf_tracepoint = { - .task_ctx_nr = perf_sw_context, - - .event_init = perf_tp_event_init, - .add = perf_trace_add, - .del = perf_trace_del, - .start = perf_swevent_start, - .stop = perf_swevent_stop, - .read = perf_swevent_read, -}; - #if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS) /* * Flags in config, used by dynamic PMU kprobe and uprobe -- cgit v1.2.3