From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752416AbcGSXVE (ORCPT ); Tue, 19 Jul 2016 19:21:04 -0400 Received: from mail-qk0-f181.google.com ([209.85.220.181]:33276 "EHLO mail-qk0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752023AbcGSXVA (ORCPT ); Tue, 19 Jul 2016 19:21:00 -0400 From: Brendan Gregg To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin Cc: linux-kernel@vger.kernel.org, Alexei Starovoitov , Wang Nan , Brendan Gregg Subject: [PATCH] perf/core: Add a tracepoint for perf sampling Date: Tue, 19 Jul 2016 23:20:48 +0000 Message-Id: <1468970448-3309-1-git-send-email-bgregg@netflix.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When perf is performing hrtimer-based sampling, this tracepoint can be used by BPF to run additional logic on each sample. For example, BPF can fetch stack traces and frequency count them in kernel context, for an efficient profiler. Signed-off-by: Brendan Gregg Cc: Alexei Starovoitov Cc: Wang Nan --- include/trace/events/perf.h | 29 +++++++++++++++++++++++++++++ kernel/events/core.c | 5 +++++ 2 files changed, 34 insertions(+) create mode 100644 include/trace/events/perf.h diff --git a/include/trace/events/perf.h b/include/trace/events/perf.h new file mode 100644 index 0000000..461770d --- /dev/null +++ b/include/trace/events/perf.h @@ -0,0 +1,29 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM perf + +#if !defined(_TRACE_PERF_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_PERF_H + +#include + +TRACE_EVENT(perf_hrtimer, + TP_PROTO(struct pt_regs *regs, struct perf_event *event), + + TP_ARGS(regs, event), + + TP_STRUCT__entry( + __field(struct pt_regs *, regs) + __field(struct perf_event *, event) + ), + + TP_fast_assign( + __entry->regs = regs; + __entry->event = event; + ), + + TP_printk("regs=%p evt=%p", __entry->regs, __entry->event) +); +#endif /* _TRACE_PERF_H */ + +/* This part must be outside protection */ +#include diff --git a/kernel/events/core.c b/kernel/events/core.c index 79dae18..0d843a7 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -51,6 +51,9 @@ #include +#define CREATE_TRACE_POINTS +#include + typedef int (*remote_function_f)(void *); struct remote_function_call { @@ -8036,6 +8039,8 @@ static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) perf_sample_data_init(&data, 0, event->hw.last_period); regs = get_irq_regs(); + trace_perf_hrtimer(regs, event); + if (regs && !perf_exclude_event(event, regs)) { if (!(event->attr.exclude_idle && is_idle_task(current))) if (__perf_event_overflow(event, 1, &data, regs)) -- 2.7.4