timer: fix TSC frequency by not reading /proc/cpuinfo

[dpdk.git] / lib / librte_eal / linuxapp / eal / eal_timer.c

diff --git a/lib/librte_eal/linuxapp/eal/eal_timer.c b/lib/librte_eal/linuxapp/eal/eal_timer.c
index d046f59..64566d1 100644 (file)
--- a/lib/librte_eal/linuxapp/eal/eal_timer.c
+++ b/lib/librte_eal/linuxapp/eal/eal_timer.c
@@ -1,35 +1,35 @@
 /*-
  *   BSD LICENSE
  * 
- *   Copyright(c) 2010-2013 Intel Corporation. All rights reserved.
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   Copyright(c) 2012-2013 6WIND S.A.
  *   All rights reserved.
  * 
- *   Redistribution and use in source and binary forms, with or without 
- *   modification, are permitted provided that the following conditions 
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
  *   are met:
  * 
- *     * Redistributions of source code must retain the above copyright 
+ *     * Redistributions of source code must retain the above copyright
  *       notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above copyright 
- *       notice, this list of conditions and the following disclaimer in 
- *       the documentation and/or other materials provided with the 
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
  *       distribution.
- *     * Neither the name of Intel Corporation nor the names of its 
- *       contributors may be used to endorse or promote products derived 
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
  *       from this software without specific prior written permission.
  * 
- *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
- *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
- *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 
- *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
- *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
- *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
- *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 
- *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
- *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
- *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- * 
  */
 
 #include <string.h>
@@ -243,6 +243,41 @@ rte_eal_hpet_init(int make_default)
 }
 #endif
 
+static void
+check_tsc_flags(void)
+{
+       char line[512];
+       FILE *stream;
+
+       stream = fopen("/proc/cpuinfo", "r");
+       if (!stream) {
+               RTE_LOG(WARNING, EAL, "WARNING: Unable to open /proc/cpuinfo\n");
+               return;
+       }
+
+       while (fgets(line, sizeof line, stream)) {
+               char *constant_tsc;
+               char *nonstop_tsc;
+
+               if (strncmp(line, "flags", 5) != 0)
+                       continue;
+
+               constant_tsc = strstr(line, "constant_tsc");
+               nonstop_tsc = strstr(line, "nonstop_tsc");
+               if (!constant_tsc || !nonstop_tsc)
+                       RTE_LOG(WARNING, EAL,
+                               "WARNING: cpu flags "
+                               "constant_tsc=%s "
+                               "nonstop_tsc=%s "
+                               "-> using unreliable clock cycles !\n",
+                               constant_tsc ? "yes":"no",
+                               nonstop_tsc ? "yes":"no");
+               break;
+       }
+
+       fclose(stream);
+}
+
 static int
 set_tsc_freq_from_clock(void)
 {
@@ -305,5 +340,6 @@ rte_eal_timer_init(void)
        eal_timer_source = EAL_TIMER_TSC;
 
        set_tsc_freq();
+       check_tsc_flags();
        return 0;
 }