From: Ivan Boule <ivan.bo...@6wind.com>
Read flags from /proc/cpuinfo and warn if constant_tsc or nonstop_tsc is
not found.
Acked-by: Ivan Boule <ivan.boule at 6wind.com>
Signed-off-by: Thomas Monjalon <thomas.monjalon at 6wind.com>
---
lib/librte_eal/linuxapp/eal/eal_hpet.c | 37 ++++++++++++++++++++++++++++++++
1 files changed, 37 insertions(+), 0 deletions(-)
diff --git a/lib/librte_eal/linuxapp/eal/eal_hpet.c
b/lib/librte_eal/linuxapp/eal/eal_hpet.c
index aa686b1..de05151 100644
--- a/lib/librte_eal/linuxapp/eal/eal_hpet.c
+++ b/lib/librte_eal/linuxapp/eal/eal_hpet.c
@@ -2,6 +2,7 @@
* BSD LICENSE
*
* Copyright(c) 2010-2012 Intel Corporation. All rights reserved.
+ * Copyright(c) 2012-2013 6WIND.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -140,6 +141,41 @@ set_rdtsc_freq(void)
((1.0 / eal_hpet_resolution_hz) / 1e-15);
}
+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);
+}
+
/*
* Open and mmap /dev/hpet (high precision event timer) that will
* provide our time reference.
@@ -192,6 +228,7 @@ rte_eal_hpet_init(void)
use_rdtsc:
internal_config.no_hpet = 1;
set_rdtsc_freq();
+ check_tsc_flags();
return 0;
}
--
1.7.2.5
