diff --git a/trunk/src/app/srs_app_server.cpp b/trunk/src/app/srs_app_server.cpp
index 4b5c072bc..590cd6461 100644
--- a/trunk/src/app/srs_app_server.cpp
+++ b/trunk/src/app/srs_app_server.cpp
@@ -74,9 +74,6 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 // update the disk iops interval:
 //      SRS_SYS_CYCLE_INTERVAL * SRS_SYS_DISK_STAT_RESOLUTION_TIMES
-// @remark, depends on SRS_SYS_CPU_STAT_RESOLUTION_TIMES, for the disk util
-//      depends on cpu time, so the disk stat times must be times of cpu stat time.
-//      for example, when cpu is 30, disk must be 30*1 or 30*2 ..., 30*N is ok.
 #define SRS_SYS_DISK_STAT_RESOLUTION_TIMES 60
 
 // update rusage interval:
diff --git a/trunk/src/app/srs_app_utility.cpp b/trunk/src/app/srs_app_utility.cpp
index e8e60ec55..67392f7f3 100644
--- a/trunk/src/app/srs_app_utility.cpp
+++ b/trunk/src/app/srs_app_utility.cpp
@@ -490,6 +490,9 @@ void srs_update_disk_stat()
     if (!srs_get_disk_diskstats_stat(r)) {
         return;
     }
+    if (!get_proc_system_stat(r.cpu)) {
+        return;
+    }
     
     SrsDiskStat& o = _srs_disk_stat;
     if (!o.ok) {
@@ -513,16 +516,16 @@ void srs_update_disk_stat()
     }
     
     // diskstats
-    if (true) {
-        SrsProcSystemStat* cpu = srs_get_system_proc_stat();
+    if (r.cpu.ok && o.cpu.ok) {
         SrsCpuInfo* cpuinfo = srs_get_cpuinfo();
+        r.cpu.total_delta = r.cpu.total() - o.cpu.total();
         
-        if (cpu->ok && cpu->total_delta > 0 
+        if (r.cpu.ok && r.cpu.total_delta > 0
             && cpuinfo->ok && cpuinfo->nb_processors > 0
             && o.ticks < r.ticks
         ) {
             // @see: print_partition_stats() of iostat.c
-            double delta_ms = cpu->total_delta * 10 / cpuinfo->nb_processors;
+            double delta_ms = r.cpu.total_delta * 10 / cpuinfo->nb_processors;
             unsigned int ticks = r.ticks - o.ticks;
             
             // busy in [0, 1], where 0.1532 means 15.32%
diff --git a/trunk/src/app/srs_app_utility.hpp b/trunk/src/app/srs_app_utility.hpp
index 5384c8e04..a8d6b6af9 100644
--- a/trunk/src/app/srs_app_utility.hpp
+++ b/trunk/src/app/srs_app_utility.hpp
@@ -341,6 +341,8 @@ public:
     // @see: print_partition_stats() of iostat.c
     // but its value is [0, +], for instance, 0.1532 means 15.32%.
     float busy;
+    // for stat the busy%
+    SrsProcSystemStat cpu;
     
 public:
     // @see: cat /proc/vmstat