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perf ftrace: Add option for function filtering

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The -T/--trace-funcs and -N/--notrace-funcs options are to specify
functions to enable/disable tracing dynamically.

The -G/--graph-funcs and -g/--nograph-funcs options are to set filters
for function graph tracer.

For example, to trace fault handling functions only:

  $ sudo perf ftrace -T *fault hello
   0)               |  __do_page_fault() {
   0)               |    handle_mm_fault() {
   0)   2.117 us    |      __handle_mm_fault();
   0)   3.627 us    |    }
   0)   7.811 us    |  }
   0)               |  __do_page_fault() {
   0)               |    handle_mm_fault() {
   0)   2.014 us    |      __handle_mm_fault();
   0)   2.424 us    |    }
   0)   2.951 us    |  }
   ...

To trace all functions executed in __do_page_fault:

  $ sudo perf ftrace -G __do_page_fault hello
   2)               |  __do_page_fault() {
   3)   0.060 us    |    down_read_trylock();
   3)               |    find_vma() {
   3)   0.075 us    |      vmacache_find();
   3)   0.053 us    |      vmacache_update();
   3)   1.246 us    |    }
   3)               |    handle_mm_fault() {
   3)   0.063 us    |      __rcu_read_lock();
   3)   0.056 us    |      mem_cgroup_from_task();
   3)   0.057 us    |      __rcu_read_unlock();
   3)               |      __handle_mm_fault() {
   3)               |        filemap_map_pages() {
   3)   0.058 us    |          __rcu_read_lock();
   3)               |          alloc_set_pte() {
   ...

But don't want to show details in handle_mm_fault:

  $ sudo perf ftrace -G __do_page_fault -g handle_mm_fault hello
   3)               |  __do_page_fault() {
   3)   0.049 us    |    down_read_trylock();
   3)               |    find_vma() {
   3)   0.048 us    |      vmacache_find();
   3)   0.041 us    |      vmacache_update();
   3)   0.680 us    |    }
   3)   0.036 us    |    up_read();
   3)   4.547 us    |  } /* __do_page_fault */
   ...

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170618142302.25390-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2017-06-18 23:23:01 +09:00 committed by Arnaldo Carvalho de Melo
parent 29681bc5bb
commit 78b83e8b12
2 changed files with 141 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
tools/perf/Documentation/perf-ftrace.txt
View File

@ -48,6 +48,36 @@ OPTIONS
Ranges of CPUs are specified with -: 0-2.
Default is to trace on all online CPUs.
-T::
--trace-funcs=::
Only trace functions given by the argument. Multiple functions
can be given by using this option more than once. The function
argument also can be a glob pattern. It will be passed to
'set_ftrace_filter' in tracefs.
-N::
--notrace-funcs=::
Do not trace functions given by the argument. Like -T option,
this can be used more than once to specify multiple functions
(or glob patterns). It will be passed to 'set_ftrace_notrace'
in tracefs.
-G::
--graph-funcs=::
Set graph filter on the given function (or a glob pattern).
This is useful for the function_graph tracer only and enables
tracing for functions executed from the given function.
This can be used more than once to specify multiple functions.
It will be passed to 'set_graph_function' in tracefs.
-g::
--nograph-funcs=::
Set graph notrace filter on the given function (or a glob pattern).
Like -G option, this is useful for the function_graph tracer only
and disables tracing for function executed from the given function.
This can be used more than once to specify multiple functions.
It will be passed to 'set_graph_notrace' in tracefs.
SEE ALSO
--------

117
tools/perf/builtin-ftrace.c
View File

@ -28,9 +28,18 @@
#define DEFAULT_TRACER "function_graph"
struct perf_ftrace {
struct perf_evlist *evlist;
struct target target;
const char *tracer;
struct perf_evlist *evlist;
struct target target;
const char *tracer;
struct list_head filters;
struct list_head notrace;
struct list_head graph_funcs;
struct list_head nograph_funcs;
};
struct filter_entry {
struct list_head list;
char name[];
};
static bool done;
@ -104,6 +113,7 @@ static int append_tracing_file(const char *name, const char *val)
}
static int reset_tracing_cpu(void);
static void reset_tracing_filters(void);
static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
{
@ -119,6 +129,7 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
if (reset_tracing_cpu() < 0)
return -1;
reset_tracing_filters();
return 0;
}
@ -184,6 +195,48 @@ static int reset_tracing_cpu(void)
return ret;
}
static int __set_tracing_filter(const char *filter_file, struct list_head *funcs)
{
struct filter_entry *pos;
list_for_each_entry(pos, funcs, list) {
if (append_tracing_file(filter_file, pos->name) < 0)
return -1;
}
return 0;
}
static int set_tracing_filters(struct perf_ftrace *ftrace)
{
int ret;
ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters);
if (ret < 0)
return ret;
ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace);
if (ret < 0)
return ret;
ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs);
if (ret < 0)
return ret;
/* old kernels do not have this filter */
__set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs);
return ret;
}
static void reset_tracing_filters(void)
{
write_tracing_file("set_ftrace_filter", " ");
write_tracing_file("set_ftrace_notrace", " ");
write_tracing_file("set_graph_function", " ");
write_tracing_file("set_graph_notrace", " ");
}
static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
{
char *trace_file;
@ -226,6 +279,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
goto out_reset;
}
if (set_tracing_filters(ftrace) < 0) {
pr_err("failed to set tracing filters\n");
goto out_reset;
}
if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
goto out_reset;
@ -310,6 +368,32 @@ static int perf_ftrace_config(const char *var, const char *value, void *cb)
return -1;
}
static int parse_filter_func(const struct option *opt, const char *str,
int unset __maybe_unused)
{
struct list_head *head = opt->value;
struct filter_entry *entry;
entry = malloc(sizeof(*entry) + strlen(str) + 1);
if (entry == NULL)
return -ENOMEM;
strcpy(entry->name, str);
list_add_tail(&entry->list, head);
return 0;
}
static void delete_filter_func(struct list_head *head)
{
struct filter_entry *pos, *tmp;
list_for_each_entry_safe(pos, tmp, head, list) {
list_del(&pos->list);
free(pos);
}
}
int cmd_ftrace(int argc, const char **argv)
{
int ret;
@ -333,9 +417,22 @@ int cmd_ftrace(int argc, const char **argv)
"system-wide collection from all CPUs"),
OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
"list of cpus to monitor"),
OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
"trace given functions only", parse_filter_func),
OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
"do not trace given functions", parse_filter_func),
OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
"Set graph filter on given functions", parse_filter_func),
OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
"Set nograph filter on given functions", parse_filter_func),
OPT_END()
};
INIT_LIST_HEAD(&ftrace.filters);
INIT_LIST_HEAD(&ftrace.notrace);
INIT_LIST_HEAD(&ftrace.graph_funcs);
INIT_LIST_HEAD(&ftrace.nograph_funcs);
ret = perf_config(perf_ftrace_config, &ftrace);
if (ret < 0)
return -1;
@ -351,12 +448,14 @@ int cmd_ftrace(int argc, const char **argv)
target__strerror(&ftrace.target, ret, errbuf, 512);
pr_err("%s\n", errbuf);
return -EINVAL;
goto out_delete_filters;
}
ftrace.evlist = perf_evlist__new();
if (ftrace.evlist == NULL)
return -ENOMEM;
if (ftrace.evlist == NULL) {
ret = -ENOMEM;
goto out_delete_filters;
}
ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target);
if (ret < 0)
@ -367,5 +466,11 @@ int cmd_ftrace(int argc, const char **argv)
out_delete_evlist:
perf_evlist__delete(ftrace.evlist);
out_delete_filters:
delete_filter_func(&ftrace.filters);
delete_filter_func(&ftrace.notrace);
delete_filter_func(&ftrace.graph_funcs);
delete_filter_func(&ftrace.nograph_funcs);
return ret;
}