perf trace: Allow specifying which syscalls to trace

Similar to -e in strace, i.e. a comma separated list of syscall names
to trace.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-5zku7q5wug3103k1dzn3yy63@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt
index 68718ccdd17820cfb38b4daab837b321874a096f..3b3552a8959ed28e9f91a5d5b95dca4817c0b135 100644 (file)
--- a/tools/perf/Documentation/perf-trace.txt
+++ b/tools/perf/Documentation/perf-trace.txt
@@ -26,6 +26,10 @@ OPTIONS
 --all-cpus::
         System-wide collection from all CPUs.
 
+-e::
+--expr::
+       List of events to show, currently only syscall names.
+
 -p::
 --pid=::
        Record events on existing process ID (comma separated list).

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index da7ae01c83943d6bd2a8cf2cce49582d4aea4b1e..120fdfb3d920f303de89027c8b9998b5ac8330ab 100644 (file)
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -5,6 +5,7 @@
 #include "util/machine.h"
 #include "util/thread.h"
 #include "util/parse-options.h"
+#include "util/strlist.h"
 #include "util/thread_map.h"
 
 #include <libaudit.h>
@@ -47,6 +48,7 @@ static struct syscall_fmt *syscall_fmt__find(const char *name)
 struct syscall {
        struct event_format *tp_format;
        const char          *name;
+       bool                filtered;
        struct syscall_fmt  *fmt;
 };
 
@@ -110,6 +112,7 @@ struct trace {
        struct perf_record_opts opts;
        struct machine          host;
        u64                     base_time;
+       struct strlist          *ev_qualifier;
        unsigned long           nr_events;
        bool                    sched;
        bool                    multiple_threads;
@@ -226,6 +229,16 @@ static int trace__read_syscall_info(struct trace *trace, int id)
 
        sc = trace->syscalls.table + id;
        sc->name = name;
+
+       if (trace->ev_qualifier && !strlist__find(trace->ev_qualifier, name)) {
+               sc->filtered = true;
+               /*
+                * No need to do read tracepoint information since this will be
+                * filtered out.
+                */
+               return 0;
+       }
+
        sc->fmt  = syscall_fmt__find(sc->name);
 
        snprintf(tp_name, sizeof(tp_name), "sys_enter_%s", sc->name);
@@ -302,11 +315,19 @@ static int trace__sys_enter(struct trace *trace, struct perf_evsel *evsel,
        char *msg;
        void *args;
        size_t printed = 0;
-       struct thread *thread = machine__findnew_thread(&trace->host, sample->tid);
+       struct thread *thread;
        struct syscall *sc = trace__syscall_info(trace, evsel, sample);
-       struct thread_trace *ttrace = thread__trace(thread);
+       struct thread_trace *ttrace;
+
+       if (sc == NULL)
+               return -1;
 
-       if (ttrace == NULL || sc == NULL)
+       if (sc->filtered)
+               return 0;
+
+       thread = machine__findnew_thread(&trace->host, sample->tid);
+       ttrace = thread__trace(thread);
+       if (ttrace == NULL)
                return -1;
 
        args = perf_evsel__rawptr(evsel, sample, "args");
@@ -345,11 +366,19 @@ static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel,
 {
        int ret;
        u64 duration = 0;
-       struct thread *thread = machine__findnew_thread(&trace->host, sample->tid);
-       struct thread_trace *ttrace = thread__trace(thread);
+       struct thread *thread;
        struct syscall *sc = trace__syscall_info(trace, evsel, sample);
+       struct thread_trace *ttrace;
+
+       if (sc == NULL)
+               return -1;
 
-       if (ttrace == NULL || sc == NULL)
+       if (sc->filtered)
+               return 0;
+
+       thread = machine__findnew_thread(&trace->host, sample->tid);
+       ttrace = thread__trace(thread);
+       if (ttrace == NULL)
                return -1;
 
        ret = perf_evsel__intval(evsel, sample, "ret");
@@ -634,7 +663,10 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
                        .mmap_pages    = 1024,
                },
        };
+       const char *ev_qualifier_str = NULL;
        const struct option trace_options[] = {
+       OPT_STRING('e', "expr", &ev_qualifier_str, "expr",
+                   "list of events to trace"),
        OPT_STRING('p', "pid", &trace.opts.target.pid, "pid",
                    "trace events on existing process id"),
        OPT_STRING(0, "tid", &trace.opts.target.tid, "tid",
@@ -660,6 +692,14 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
 
        argc = parse_options(argc, argv, trace_options, trace_usage, 0);
 
+       if (ev_qualifier_str != NULL) {
+               trace.ev_qualifier = strlist__new(true, ev_qualifier_str);
+               if (trace.ev_qualifier == NULL) {
+                       puts("Not enough memory to parse event qualifier");
+                       return -ENOMEM;
+               }
+       }
+
        err = perf_target__validate(&trace.opts.target);
        if (err) {
                perf_target__strerror(&trace.opts.target, err, bf, sizeof(bf));