perf trace: Support ! in -e expressions

So that we can ask for all but a set of syscalls to be traced.

Cc: Adrian Hunter <adrian.hunter@intel.com>
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-9j6hvap23qanyl96wx4mrj9k@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 21 insertions, 9 deletions

diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt
index cb3371eb597d..4754f11a862b 100644
--- a/tools/perf/Documentation/perf-trace.txt
+++ b/tools/perf/Documentation/perf-trace.txt
@@ -30,6 +30,8 @@ OPTIONS
 -e::
 --expr::
         List of events to show, currently only syscall names.
+        Prefixing with ! shows all syscalls but the ones specified.  You may
+        need to escape it.
 
 -o::
 --output=::
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 9891d8cdb73d..6ab7a7a5e66e 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -114,8 +114,9 @@ struct trace {
         struct machine          host;
         u64                     base_time;
         FILE                    *output;
-        struct strlist          *ev_qualifier;
         unsigned long           nr_events;
+        struct strlist          *ev_qualifier;
+        bool                    not_ev_qualifier;
         bool                    sched;
         bool                    multiple_threads;
         double                  duration_filter;
@@ -234,13 +235,17 @@ 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;
+        if (trace->ev_qualifier) {
+                bool in = strlist__find(trace->ev_qualifier, name) != NULL;
+
+                if (!(in ^ trace->not_ev_qualifier)) {
+                        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);
@@ -725,7 +730,12 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
         }
 
         if (ev_qualifier_str != NULL) {
-                trace.ev_qualifier = strlist__new(true, ev_qualifier_str);
+                const char *s = ev_qualifier_str;
+
+                trace.not_ev_qualifier = *s == '!';
+                if (trace.not_ev_qualifier)
+                        ++s;
+                trace.ev_qualifier = strlist__new(true, s);
                 if (trace.ev_qualifier == NULL) {
                         fputs("Not enough memory to parse event qualifier",
                               trace.output);