From: Jim Harris <james.r.harris@intel.com>
To: dev@dpdk.org, anatoly.burakov@intel.com
Subject: [dpdk-dev] [PATCH v2 2/2] timer: don't check tsc flags in secondary processes
Date: Fri, 16 Aug 2019 05:02:36 -0700 [thread overview]
Message-ID: <156595695619.7484.7837232961573133745.stgit@jrharri1-skx> (raw)
In-Reply-To: <156595695082.7484.13482698229756801845.stgit@jrharri1-skx>
check_tsc_flags() parses /proc/cpuinfo and prints
warning messages if any cores don't have constant_tsc
and nonstop_tsc. It has no functional meaning.
This consumes a noticeable amount of time in
secondary processes - on my test system, it consumes
21ms out of the 66ms total execution time for
rte_eal_init().
So let's just skip checking these flags in secondary
processes. Since the primary process is already
parsing the entirety of /proc/cpuinfo, the warning
printed in the primary process should be sufficient.
Signed-off-by: Jim Harris <james.r.harris@intel.com>
---
lib/librte_eal/linux/eal/eal_timer.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/lib/librte_eal/linux/eal/eal_timer.c b/lib/librte_eal/linux/eal/eal_timer.c
index 76ec17034..ce447d43b 100644
--- a/lib/librte_eal/linux/eal/eal_timer.c
+++ b/lib/librte_eal/linux/eal/eal_timer.c
@@ -198,6 +198,15 @@ check_tsc_flags(void)
char line[512];
FILE *stream;
+ if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
+ /* This function just prints warnings if TSC is not constant
+ * and has no functional meaning. It also checks *all* cores
+ * on the system, not just the ones configured for this process.
+ * So don't bother rechecking again in secondary processes.
+ */
+ return;
+ }
+
stream = fopen("/proc/cpuinfo", "r");
if (!stream) {
RTE_LOG(WARNING, EAL, "WARNING: Unable to open /proc/cpuinfo\n");
prev parent reply other threads:[~2019-08-16 19:07 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-16 12:02 [dpdk-dev] [PATCH v2 1/2] timer: use rte_mp_msg to pass TSC hz to secondary procs Jim Harris
2019-08-16 12:02 ` Jim Harris [this message]
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