perf report: Add support for profiling JIT generated code

This patch adds support for profiling JIT generated code to 'perf
report'. A JIT compiler is required to generate a "/tmp/perf-$PID.map"
symbols map that is parsed when looking and displaying symbols.

Thanks to Peter Zijlstra for his help with this patch!

Example "perf report" output with the Jato JIT:

 #
 # (40311 samples)
 #
 # Overhead           Command  Shared Object              Symbol
 # ........  ................  .........................  ......
 #
     97.80%              jato  /tmp/perf-11915.map        [.] Fibonacci.fib(I)I
      0.56%              jato  00000000b7fa023b           0x000000b7fa023b
      0.45%              jato  /tmp/perf-11915.map        [.] Fibonacci.main([Ljava/lang/String;)V
      0.38%              jato  [kernel]                   [k] get_page_from_freelist
      0.06%              jato  [kernel]                   [k] kunmap_atomic
      0.05%              jato  ./jato                     [.] utf8Hash
      0.04%              jato  ./jato                     [.] executeJava
      0.04%              jato  ./jato                     [.] defineClass

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: a.p.zijlstra@chello.nl
Cc: acme@redhat.com
LKML-Reference: <Pine.LNX.4.64.0906082111590.12407@melkki.cs.Helsinki.FI>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index f053a74..61d8718 100644 (file)
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -209,6 +209,11 @@ static uint64_t vdso__map_ip(struct map *map, uint64_t ip)
        return ip;
 }
 
+static inline int is_anon_memory(const char *filename)
+{
+     return strcmp(filename, "//anon") == 0;
+}
+
 static struct map *map__new(struct mmap_event *event)
 {
        struct map *self = malloc(sizeof(*self));
@@ -216,6 +221,7 @@ static struct map *map__new(struct mmap_event *event)
        if (self != NULL) {
                const char *filename = event->filename;
                char newfilename[PATH_MAX];
+               int anon;
 
                if (cwd) {
                        int n = strcommon(filename);
@@ -227,6 +233,13 @@ static struct map *map__new(struct mmap_event *event)
                        }
                }
 
+               anon = is_anon_memory(filename);
+
+               if (anon) {
+                       snprintf(newfilename, sizeof(newfilename), "/tmp/perf-%d.map", event->pid);
+                       filename = newfilename;
+               }
+
                self->start = event->start;
                self->end   = event->start + event->len;
                self->pgoff = event->pgoff;
@@ -235,7 +248,7 @@ static struct map *map__new(struct mmap_event *event)
                if (self->dso == NULL)
                        goto out_delete;
 
-               if (self->dso == vdso)
+               if (self->dso == vdso || anon)
                        self->map_ip = vdso__map_ip;
                else
                        self->map_ip = map__map_ip;

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 158588c..32dd47d 100644 (file)
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -220,6 +220,68 @@ out_failure:
        return -1;
 }
 
+static int dso__load_perf_map(struct dso *self, symbol_filter_t filter, int verbose)
+{
+       char *line = NULL;
+       size_t n;
+       FILE *file;
+       int nr_syms = 0;
+
+       file = fopen(self->name, "r");
+       if (file == NULL)
+               goto out_failure;
+
+       while (!feof(file)) {
+               __u64 start, size;
+               struct symbol *sym;
+               int line_len, len;
+
+               line_len = getline(&line, &n, file);
+               if (line_len < 0)
+                       break;
+
+               if (!line)
+                       goto out_failure;
+
+               line[--line_len] = '\0'; /* \n */
+
+               len = hex2u64(line, &start);
+
+               len++;
+               if (len + 2 >= line_len)
+                       continue;
+
+               len += hex2u64(line + len, &size);
+
+               len++;
+               if (len + 2 >= line_len)
+                       continue;
+
+               sym = symbol__new(start, size, line + len,
+                                 self->sym_priv_size, start, verbose);
+
+               if (sym == NULL)
+                       goto out_delete_line;
+
+               if (filter && filter(self, sym))
+                       symbol__delete(sym, self->sym_priv_size);
+               else {
+                       dso__insert_symbol(self, sym);
+                       nr_syms++;
+               }
+       }
+
+       free(line);
+       fclose(file);
+
+       return nr_syms;
+
+out_delete_line:
+       free(line);
+out_failure:
+       return -1;
+}
+
 /**
  * elf_symtab__for_each_symbol - iterate thru all the symbols
  *
@@ -507,6 +569,9 @@ int dso__load(struct dso *self, symbol_filter_t filter, int verbose)
        if (!name)
                return -1;
 
+       if (strncmp(self->name, "/tmp/perf-", 10) == 0)
+               return dso__load_perf_map(self, filter, verbose);
+
 more:
        do {
                switch (variant) {