From 1e6d5a960820a377e2453a13c8cd2e6797dc2f76 Mon Sep 17 00:00:00 2001 From: Bruce Richardson Date: Mon, 24 Apr 2017 14:04:22 +0100 Subject: [PATCH] examples/performance-thread: fix compilation on Suse 11 SP2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fixes following compilation error, using uint64_t type, instead of int128_t unnecessarily: In file included from ./common/lthread.c:82:0: ./common/lthread_timer.h: In function ‘_ns_to_clks’: ./common/lthread_timer.h:49:20: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘clkns’ compilation terminated due to -Wfatal-errors. Fixes: 116819b9ed0d ("examples/performance-thread: add lthread subsystem") Cc: stable@dpdk.org Signed-off-by: Bruce Richardson Acked-by: Pablo de Lara --- .../performance-thread/common/lthread_timer.h | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/examples/performance-thread/common/lthread_timer.h b/examples/performance-thread/common/lthread_timer.h index b044b902b1..7c03d67369 100644 --- a/examples/performance-thread/common/lthread_timer.h +++ b/examples/performance-thread/common/lthread_timer.h @@ -46,11 +46,22 @@ extern "C" { static inline uint64_t _ns_to_clks(uint64_t ns) { - unsigned __int128 clkns = rte_get_tsc_hz(); + /* + * clkns needs to be divided by 1E9 to get ns clocks. However, + * dividing by this first would lose a lot of accuracy. + * Dividing after a multiply by ns, could cause overflow of + * uint64_t if ns is about 5 seconds [if we assume a max tsc + * rate of 4GHz]. Therefore we first divide by 1E4, then + * multiply and finally divide by 1E5. This allows ns to be + * values many hours long, without overflow, while still keeping + * reasonable accuracy. + */ + uint64_t clkns = rte_get_tsc_hz() / 1e4; clkns *= ns; - clkns /= 1000000000; - return (uint64_t) clkns; + clkns /= 1e5; + + return clkns; }