From 6bedfab68666afac1b03f8d62ee037c6ab82fbc5 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Sun, 2 Mar 2014 16:56:40 +0100 Subject: [PATCH] perf tools: Disable user-space callchain/stack dumps for function trace events User space callchains and user space stack dump were disabled for function trace event. Mailing list discussions: http://marc.info/?t=139302086500001&r=1&w=2 http://marc.info/?t=139301437300003&r=1&w=2 Catching up with perf and disabling user space callchains and DWARF unwind (uses user stack dump) for function trace event. Adding following warnings when callchains are used for function trace event: # perf record -g -e ftrace:function ... Disabling user space callchains for function trace event. ... # ./perf record --call-graph=dwarf -e ftrace:function ... Cannot use DWARF unwind for function trace event, falling back to framepointers. Disabling user space callchains for function trace event. ... Signed-off-by: Jiri Olsa Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: "H. Peter Anvin" Cc: Vince Weaver Cc: Steven Rostedt Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1393775800-13524-4-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar --- tools/perf/util/evsel.c | 41 ++++++++++++++++++++++++++++++----------- tools/perf/util/evsel.h | 18 ++++++++++++++++++ 2 files changed, 48 insertions(+), 11 deletions(-) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index adc94dd1794d..26b67b11c65b 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -500,6 +500,34 @@ int perf_evsel__group_desc(struct perf_evsel *evsel, char *buf, size_t size) return ret; } +static void +perf_evsel__config_callgraph(struct perf_evsel *evsel, + struct record_opts *opts) +{ + bool function = perf_evsel__is_function_event(evsel); + struct perf_event_attr *attr = &evsel->attr; + + perf_evsel__set_sample_bit(evsel, CALLCHAIN); + + if (opts->call_graph == CALLCHAIN_DWARF) { + if (!function) { + perf_evsel__set_sample_bit(evsel, REGS_USER); + perf_evsel__set_sample_bit(evsel, STACK_USER); + attr->sample_regs_user = PERF_REGS_MASK; + attr->sample_stack_user = opts->stack_dump_size; + attr->exclude_callchain_user = 1; + } else { + pr_info("Cannot use DWARF unwind for function trace event," + " falling back to framepointers.\n"); + } + } + + if (function) { + pr_info("Disabling user space callchains for function trace event.\n"); + attr->exclude_callchain_user = 1; + } +} + /* * The enable_on_exec/disabled value strategy: * @@ -595,17 +623,8 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts) attr->mmap_data = track; } - if (opts->call_graph_enabled) { - perf_evsel__set_sample_bit(evsel, CALLCHAIN); - - if (opts->call_graph == CALLCHAIN_DWARF) { - perf_evsel__set_sample_bit(evsel, REGS_USER); - perf_evsel__set_sample_bit(evsel, STACK_USER); - attr->sample_regs_user = PERF_REGS_MASK; - attr->sample_stack_user = opts->stack_dump_size; - attr->exclude_callchain_user = 1; - } - } + if (opts->call_graph_enabled) + perf_evsel__config_callgraph(evsel, opts); if (target__has_cpu(&opts->target)) perf_evsel__set_sample_bit(evsel, CPU); diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index f1b325665aae..0c9926cfb292 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -315,6 +315,24 @@ static inline bool perf_evsel__is_group_event(struct perf_evsel *evsel) return perf_evsel__is_group_leader(evsel) && evsel->nr_members > 1; } +/** + * perf_evsel__is_function_event - Return whether given evsel is a function + * trace event + * + * @evsel - evsel selector to be tested + * + * Return %true if event is function trace event + */ +static inline bool perf_evsel__is_function_event(struct perf_evsel *evsel) +{ +#define FUNCTION_EVENT "ftrace:function" + + return evsel->name && + !strncmp(FUNCTION_EVENT, evsel->name, sizeof(FUNCTION_EVENT)); + +#undef FUNCTION_EVENT +} + struct perf_attr_details { bool freq; bool verbose; -- 2.20.1