perf tools: Introduce per user view

The new --uid command line option will show only the tasks for a given
user, using the proc interface to figure out the existing tasks.

Kernel work is needed to close races at startup, but this should already
be useful in many use cases.

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-bdnspm000gw2l984a2t53o8z@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/tools/perf/util/usage.c b/tools/perf/util/usage.c
index d76d1c0ff98f..d0c013934f30 100644
--- a/tools/perf/util/usage.c
+++ b/tools/perf/util/usage.c
@@ -7,6 +7,7 @@
  * Copyright (C) Linus Torvalds, 2005
  */
 #include "util.h"
+#include "debug.h"
 
 static void report(const char *prefix, const char *err, va_list params)
 {
@@ -81,3 +82,41 @@ void warning(const char *warn, ...)
         warn_routine(warn, params);
         va_end(params);
 }
+
+uid_t parse_target_uid(const char *str, pid_t tid, pid_t pid)
+{
+        struct passwd pwd, *result;
+        char buf[1024];
+
+        if (str == NULL)
+                return UINT_MAX;
+
+        /* CPU and PID are mutually exclusive */
+        if (tid > 0 || pid > 0) {
+                ui__warning("PID/TID switch overriding UID\n");
+                sleep(1);
+                return UINT_MAX;
+        }
+
+        getpwnam_r(str, &pwd, buf, sizeof(buf), &result);
+
+        if (result == NULL) {
+                char *endptr;
+                int uid = strtol(str, &endptr, 10);
+
+                if (*endptr != '\0') {
+                        ui__error("Invalid user %s\n", str);
+                        return UINT_MAX - 1;
+                }
+
+                getpwuid_r(uid, &pwd, buf, sizeof(buf), &result);
+
+                if (result == NULL) {
+                        ui__error("Problems obtaining information for user %s\n",
+                                  str);
+                        return UINT_MAX - 1;
+                }
+        }
+
+        return result->pw_uid;
+}