1 files changed, 12 insertions, 0 deletions

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index aebba5659345..1e2f5dde312c 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -40,6 +40,7 @@ static int		dump_trace = 0;
 
 static int              verbose;
 static int              full_paths;
+static int              collapse_syscalls;
 
 static unsigned long    page_size;
 static unsigned long    mmap_window = 32;
@@ -983,6 +984,15 @@ process_overflow_event(event_t *event, unsigned long offset, unsigned long head)
                         for (i = 0; i < chain->nr; i++)
                                 dprintf("..... %2d: %p\n", i, (void *)chain->ips[i]);
                 }
+                if (collapse_syscalls) {
+                        /*
+                         * Find the all-but-last kernel entry
+                         * amongst the call-chains - to get
+                         * to the level of system calls:
+                         */
+                        if (chain->kernel >= 2)
+                                ip = chain->ips[chain->kernel-2];
+                }
         }
 
         dprintf(" ... thread: %s:%d\n", thread->comm, thread->pid);
@@ -1343,6 +1353,8 @@ static const struct option options[] = {
                    "sort by key(s): pid, comm, dso, symbol. Default: pid,symbol"),
         OPT_BOOLEAN('P', "full-paths", &full_paths,
                     "Don't shorten the pathnames taking into account the cwd"),
+        OPT_BOOLEAN('S', "syscalls", &collapse_syscalls,
+                    "show per syscall summary overhead, using call graph"),
         OPT_END()
 };