From: Thomas Monjalon <thomas.monjalon@6wind.com>
To: dev@dpdk.org
Subject: [dpdk-dev] [PATCH 16/22] timer: check TSC reliability
Date: Wed, 20 Mar 2013 17:05:04 +0100 [thread overview]
Message-ID: <0b5c378689ddbf21bd1abb63ea5e30217eb27fac.1363795499.git.thomas.monjalon@6wind.com> (raw)
In-Reply-To: <cover.1363795499.git.thomas.monjalon@6wind.com>
In-Reply-To: <cover.1363795499.git.thomas.monjalon@6wind.com>
From: Ivan Boule <ivan.boule@6wind.com>
Read flags from /proc/cpuinfo and warn if constant_tsc or nonstop_tsc is
not found.
Acked-by: Ivan Boule <ivan.boule@6wind.com>
Signed-off-by: Thomas Monjalon <thomas.monjalon@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
next prev parent reply other threads:[~2013-03-20 16:08 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-20 16:04 [dpdk-dev] [PATCH 00/22] upgrade with 6WIND's enhancements Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 01/22] mk: use $CC to detect toolchain version Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 02/22] mk: fix typo in LDFLAGS for 32-bit Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 03/22] mk: fix verbose display of install command Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 04/22] mk: add a makefile for shared libraries Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 05/22] mk: allow corei7-avx flag with gcc 4.7 Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 06/22] app: fix volatile read for GCC >= 4.6 Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 07/22] app: fix unused values Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 08/22] app: use (void)variable when unused Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 09/22] app: fix testpmd compliance with __rte_mbuf_sanity_check() Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 10/22] app: fix config crash in testpmd Thomas Monjalon
2013-03-20 16:04 ` [dpdk-dev] [PATCH 11/22] app: fix autotest summary in error cases Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 12/22] lib: fix unused values Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 13/22] lib: fix uninitialized variables Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 14/22] lib: fix non-C99 macros definitions in exported headers Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 15/22] mem: fix access to huge page with high address Thomas Monjalon
2013-03-20 16:05 ` Thomas Monjalon [this message]
2013-03-20 16:05 ` [dpdk-dev] [PATCH 17/22] timer: get TSC frequency from /proc/cpuinfo Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 18/22] timer: option --vmware-tsc-map for VMware guest Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 19/22] pci: reference driver structure for each device Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 20/22] pci: allow drivers to be bound several times to the same PCI device Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 21/22] igb_uio: fix driver dependency Thomas Monjalon
2013-03-20 16:05 ` [dpdk-dev] [PATCH 22/22] igb_uio: fix build with kernel >= 3.8 Thomas Monjalon
2013-03-20 16:58 ` [dpdk-dev] [PATCH 00/22] upgrade with 6WIND's enhancements Vincent JARDIN
2013-03-21 9:40 ` Thomas Monjalon
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