perf tools: Find the proc info under machine->root_dir.

When we synthesize the threads, we are looking for the infomation under
/proc. But it is only for host.

This patch look for the path of proc under machine->root_dir, then
XXX__synthesize_threads() functions can support guest machines.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Link: http://lkml.kernel.org/r/927b937da9177a079abafe4532fa9c9b60b5c4b7.1387572416.git.yangds.fnst@cn.fujitsu.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 484e99464a00..a61726ea01a9 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -129,7 +129,8 @@ static pid_t perf_event__synthesize_comm(struct perf_tool *tool,
                 goto out;
         }
 
-        snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
+        snprintf(filename, sizeof(filename), "%s/proc/%d/task",
+                 machine->root_dir, pid);
 
         tasks = opendir(filename);
         if (tasks == NULL) {
@@ -178,7 +179,8 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
         FILE *fp;
         int rc = 0;
 
-        snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
+        snprintf(filename, sizeof(filename), "%s/proc/%d/maps",
+                 machine->root_dir, pid);
 
         fp = fopen(filename, "r");
         if (fp == NULL) {
@@ -387,6 +389,7 @@ int perf_event__synthesize_threads(struct perf_tool *tool,
                                    struct machine *machine, bool mmap_data)
 {
         DIR *proc;
+        char proc_path[PATH_MAX];
         struct dirent dirent, *next;
         union perf_event *comm_event, *mmap_event;
         int err = -1;
@@ -399,7 +402,9 @@ int perf_event__synthesize_threads(struct perf_tool *tool,
         if (mmap_event == NULL)
                 goto out_free_comm;
 
-        proc = opendir("/proc");
+        snprintf(proc_path, sizeof(proc_path), "%s/proc", machine->root_dir);
+        proc = opendir(proc_path);
+
         if (proc == NULL)
                 goto out_free_mmap;