numam-dpdk/app/test/test_cycles.c
Jozef Martiniak b4d63fb622 eal: customize delay function
When running single-core, some drivers tend to call rte_delay_us for a
long time, and that is causing packet drops.
To avoid this, rte_delay_us can be replaced with user-defined delay
function with:

void rte_delay_us_callback_register(void(*userfunc)(unsigned));

When userfunc==rte_delay_us_block build-in blocking delay function is
restored.

Signed-off-by: Jozef Martiniak <jozmarti@cisco.com>
2016-09-26 14:48:42 +02:00

138 lines
3.7 KiB
C

/*-
* BSD LICENSE
*
* Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdio.h>
#include <stdint.h>
#include <rte_common.h>
#include <rte_cycles.h>
#include "test.h"
#define N 10000
/*
* Cycles test
* ===========
*
* - Loop N times and check that the timer always increments and
* never decrements during this loop.
*
* - Wait one second using rte_usleep() and check that the increment
* of cycles is correct with regard to the frequency of the timer.
*/
static int
test_cycles(void)
{
unsigned i;
uint64_t start_cycles, cycles, prev_cycles;
uint64_t hz = rte_get_timer_hz();
uint64_t max_inc = (hz / 100); /* 10 ms max between 2 reads */
/* check that the timer is always incrementing */
start_cycles = rte_get_timer_cycles();
prev_cycles = start_cycles;
for (i=0; i<N; i++) {
cycles = rte_get_timer_cycles();
if ((uint64_t)(cycles - prev_cycles) > max_inc) {
printf("increment too high or going backwards\n");
return -1;
}
prev_cycles = cycles;
}
/* check that waiting 1 second is precise */
prev_cycles = rte_get_timer_cycles();
rte_delay_us(1000000);
cycles = rte_get_timer_cycles();
if ((uint64_t)(cycles - prev_cycles) > (hz + max_inc)) {
printf("delay_us is not accurate: too long\n");
return -1;
}
if ((uint64_t)(cycles - prev_cycles) < (hz - max_inc)) {
printf("delay_us is not accurate: too short\n");
return -1;
}
return 0;
}
REGISTER_TEST_COMMAND(cycles_autotest, test_cycles);
/*
* rte_delay_us_callback test
*
* - check if callback is correctly registered/unregistered
*
*/
static unsigned int pattern;
static void my_rte_delay_us(unsigned int us)
{
pattern += us;
}
static int
test_user_delay_us(void)
{
pattern = 0;
rte_delay_us(2);
if (pattern != 0)
return -1;
/* register custom delay function */
rte_delay_us_callback_register(my_rte_delay_us);
rte_delay_us(2);
if (pattern != 2)
return -1;
rte_delay_us(3);
if (pattern != 5)
return -1;
/* restore original delay function */
rte_delay_us_callback_register(rte_delay_us_block);
rte_delay_us(3);
if (pattern != 5)
return -1;
return 0;
}
REGISTER_TEST_COMMAND(user_delay_us, test_user_delay_us);