perf_counter tools: Shorten the DSO names using cwd

[acme@emilia linux-2.6-tip]$ pwd
/home/acme/git/linux-2.6-tip

Before (still available using -P/--full-paths)

[acme@emilia linux-2.6-tip]$ perf report -P | head -10
    11.48%             perf: 7454 [kernel]: clear_page_c
     4.89%             perf: 7454 [kernel]: vsnprintf
     4.61%             perf: 7454 /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: dso__find_symbol
     4.09%             perf: 7454 [kernel]: number
     4.06%             perf: 7454 /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: dso__fprintf
     4.00%             perf: 7454 /home/acme/git/linux-2.6-tip/Documentation/perf_counter/perf: symbol_filter

New default:

[acme@emilia linux-2.6-tip]$ perf report | head -10
    11.48%             perf: 7454 [kernel]: clear_page_c
     4.89%             perf: 7454 [kernel]: vsnprintf
     4.61%             perf: 7454 ./Documentation/perf_counter/perf: dso__find_symbol
     4.09%             perf: 7454 [kernel]: number
     4.06%             perf: 7454 ./Documentation/perf_counter/perf: dso__fprintf
     4.00%             perf: 7454 ./Documentation/perf_counter/perf: symbol_filter

Suggested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20090529164859.GN4747@ghostprotocols.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 38 insertions, 3 deletions

diff --git a/Documentation/perf_counter/builtin-report.c b/Documentation/perf_counter/builtin-report.c
index 412d524dd658..4705679debae 100644
--- a/Documentation/perf_counter/builtin-report.c
+++ b/Documentation/perf_counter/builtin-report.c
@@ -23,6 +23,7 @@ static int		show_mask = SHOW_KERNEL | SHOW_USER | SHOW_HV;
 
 static int              dump_trace = 0;
 static int              verbose;
+static int              full_paths;
 
 static unsigned long    page_size;
 static unsigned long    mmap_window = 32;
@@ -134,6 +135,16 @@ static int load_kernel(void)
         return err;
 }
 
+static int strcommon(const char *pathname, const char *cwd, int cwdlen)
+{
+        int n = 0;
+
+        while (pathname[n] == cwd[n] && n < cwdlen)
+                ++n;
+
+        return n;
+}
+
 struct map {
         struct list_head node;
         uint64_t         start;
@@ -142,16 +153,28 @@ struct map {
         struct dso       *dso;
 };
 
-static struct map *map__new(struct mmap_event *event)
+static struct map *map__new(struct mmap_event *event, char *cwd, int cwdlen)
 {
         struct map *self = malloc(sizeof(*self));
 
         if (self != NULL) {
+                const char *filename = event->filename;
+                char newfilename[PATH_MAX];
+
+                if (cwd) {
+                        int n = strcommon(filename, cwd, cwdlen);
+                        if (n == cwdlen) {
+                                snprintf(newfilename, sizeof(newfilename),
+                                         ".%s", filename + n);
+                                filename = newfilename;
+                        }
+                }
+
                 self->start = event->start;
                 self->end   = event->start + event->len;
                 self->pgoff = event->pgoff;
 
-                self->dso = dsos__findnew(event->filename);
+                self->dso = dsos__findnew(filename);
                 if (self->dso == NULL)
                         goto out_delete;
         }
@@ -598,6 +621,8 @@ static int __cmd_report(void)
         int ret, rc = EXIT_FAILURE;
         uint32_t size;
         unsigned long total = 0, total_mmap = 0, total_comm = 0, total_unknown = 0;
+        char cwd[PATH_MAX], *cwdp = cwd;
+        int cwdlen;
 
         input = open(input_name, O_RDONLY);
         if (input < 0) {
@@ -621,6 +646,14 @@ static int __cmd_report(void)
                 return EXIT_FAILURE;
         }
 
+        if (!full_paths) {
+                if (getcwd(cwd, sizeof(cwd)) == NULL) {
+                        perror("failed to get the current directory");
+                        return EXIT_FAILURE;
+                }
+                cwdlen = strlen(cwd);
+        } else
+                cwdp = NULL;
 remap:
         buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ,
                            MAP_SHARED, input, offset);
@@ -710,7 +743,7 @@ more:
         } else switch (event->header.type) {
         case PERF_EVENT_MMAP: {
                 struct thread *thread = threads__findnew(event->mmap.pid);
-                struct map *map = map__new(&event->mmap);
+                struct map *map = map__new(&event->mmap, cwdp, cwdlen);
 
                 if (dump_trace) {
                         fprintf(stderr, "%p [%p]: PERF_EVENT_MMAP: [%p(%p) @ %p]: %s\n",
@@ -809,6 +842,8 @@ static const struct option options[] = {
         OPT_STRING('k', "vmlinux", &vmlinux, "file", "vmlinux pathname"),
         OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
                    "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_END()
 };