perf tools: Fix --pid option for stat

current pid option doesn't work for perf stat. Change it to what
perf record --pid acts as.

Signed-off-by: Liming Wang <liming.wang@windriver.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1262246750-2191-1-git-send-email-liming.wang@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index c70d720..e8c85d5 100644 (file)
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -44,6 +44,7 @@
 #include "util/parse-events.h"
 #include "util/event.h"
 #include "util/debug.h"
+#include "util/header.h"
 
 #include <sys/prctl.h>
 #include <math.h>
@@ -79,6 +80,8 @@ static int                    fd[MAX_NR_CPUS][MAX_COUNTERS];
 
 static int                     event_scaled[MAX_COUNTERS];
 
+static volatile int done = 0;
+
 struct stats
 {
        double n, mean, M2;
@@ -247,61 +250,64 @@ static int run_perf_stat(int argc __used, const char **argv)
        unsigned long long t0, t1;
        int status = 0;
        int counter;
-       int pid;
+       int pid = target_pid;
        int child_ready_pipe[2], go_pipe[2];
+       const bool forks = (target_pid == -1 && argc > 0);
        char buf;
 
        if (!system_wide)
                nr_cpus = 1;
 
-       if (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0) {
+       if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
                perror("failed to create pipes");
                exit(1);
        }
 
-       if ((pid = fork()) < 0)
-               perror("failed to fork");
+       if (forks) {
+               if ((pid = fork()) < 0)
+                       perror("failed to fork");
+
+               if (!pid) {
+                       close(child_ready_pipe[0]);
+                       close(go_pipe[1]);
+                       fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
+
+                       /*
+                        * Do a dummy execvp to get the PLT entry resolved,
+                        * so we avoid the resolver overhead on the real
+                        * execvp call.
+                        */
+                       execvp("", (char **)argv);
+
+                       /*
+                        * Tell the parent we're ready to go
+                        */
+                       close(child_ready_pipe[1]);
+
+                       /*
+                        * Wait until the parent tells us to go.
+                        */
+                       if (read(go_pipe[0], &buf, 1) == -1)
+                               perror("unable to read pipe");
+
+                       execvp(argv[0], (char **)argv);
+
+                       perror(argv[0]);
+                       exit(-1);
+               }
 
-       if (!pid) {
-               close(child_ready_pipe[0]);
-               close(go_pipe[1]);
-               fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
+               child_pid = pid;
 
                /*
-                * Do a dummy execvp to get the PLT entry resolved,
-                * so we avoid the resolver overhead on the real
-                * execvp call.
-                */
-               execvp("", (char **)argv);
-
-               /*
-                * Tell the parent we're ready to go
+                * Wait for the child to be ready to exec.
                 */
                close(child_ready_pipe[1]);
-
-               /*
-                * Wait until the parent tells us to go.
-                */
-               if (read(go_pipe[0], &buf, 1) == -1)
+               close(go_pipe[0]);
+               if (read(child_ready_pipe[0], &buf, 1) == -1)
                        perror("unable to read pipe");
-
-               execvp(argv[0], (char **)argv);
-
-               perror(argv[0]);
-               exit(-1);
+               close(child_ready_pipe[0]);
        }
 
-       child_pid = pid;
-
-       /*
-        * Wait for the child to be ready to exec.
-        */
-       close(child_ready_pipe[1]);
-       close(go_pipe[0]);
-       if (read(child_ready_pipe[0], &buf, 1) == -1)
-               perror("unable to read pipe");
-       close(child_ready_pipe[0]);
-
        for (counter = 0; counter < nr_counters; counter++)
                create_perf_stat_counter(counter, pid);
 
@@ -310,8 +316,12 @@ static int run_perf_stat(int argc __used, const char **argv)
         */
        t0 = rdclock();
 
-       close(go_pipe[1]);
-       wait(&status);
+       if (forks) {
+               close(go_pipe[1]);
+               wait(&status);
+       } else {
+               while(!done);
+       }
 
        t1 = rdclock();
 
@@ -417,10 +427,13 @@ static void print_stat(int argc, const char **argv)
        fflush(stdout);
 
        fprintf(stderr, "\n");
-       fprintf(stderr, " Performance counter stats for \'%s", argv[0]);
-
-       for (i = 1; i < argc; i++)
-               fprintf(stderr, " %s", argv[i]);
+       fprintf(stderr, " Performance counter stats for ");
+       if(target_pid == -1) {
+               fprintf(stderr, "\'%s", argv[0]);
+               for (i = 1; i < argc; i++)
+                       fprintf(stderr, " %s", argv[i]);
+       }else
+               fprintf(stderr, "task pid \'%d", target_pid);
 
        fprintf(stderr, "\'");
        if (run_count > 1)
@@ -445,6 +458,9 @@ static volatile int signr = -1;
 
 static void skip_signal(int signo)
 {
+       if(target_pid != -1)
+               done = 1;
+
        signr = signo;
 }
 
@@ -461,7 +477,7 @@ static void sig_atexit(void)
 }
 
 static const char * const stat_usage[] = {
-       "perf stat [<options>] <command>",
+       "perf stat [<options>] [<command>]",
        NULL
 };
 
@@ -492,7 +508,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used)
 
        argc = parse_options(argc, argv, options, stat_usage,
                PARSE_OPT_STOP_AT_NON_OPTION);
-       if (!argc)
+       if (!argc && target_pid == -1)
                usage_with_options(stat_usage, options);
        if (run_count <= 0)
                usage_with_options(stat_usage, options);