[dpdk-stable] patch 'examples/performance-thread: fix compilation on Suse 11 SP2' has been queued to LTS release 16.11.2

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

Hi,

FYI, your patch has been queued to LTS release 16.11.2

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable
yet. It will be pushed if I get no objections before 05/07/17.
So please shout if anyone has objections.

Thanks.

	--yliu

---
>From 1ae4edde5697a738dfbcd4163d2c2b2935d9880f Mon Sep 17 00:00:00 2001
From: Bruce Richardson <bruce.richardson@intel.com>
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

[ upstream commit 1e6d5a960820a377e2453a13c8cd2e6797dc2f76 ]

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")

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
---
 examples/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 b5e6fb0..2d14757 100644
--- a/examples/performance-thread/common/lthread_timer.h
+++ b/examples/performance-thread/common/lthread_timer.h
@@ -42,11 +42,22 @@
 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;
 }
 
 
-- 
1.9.0