M7350/system/extras/tests/pftest/pftest.c
2024-09-09 08:57:42 +00:00

109 lines
3.2 KiB
C

/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <sys/time.h>
#include <time.h>
#define N_PAGES (4096)
#define WARMUP (1<<10)
#define WORKLOAD (1<<24)
int numPagesList[] = {
1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
12, 14, 16, 18, 20, 24, 28, 30, 32, 34, 48, 62, 64, 66, 80,
96, 112, 128, 144, 160, 320, 480, 496, 512, 528, 544, 576, 640, 960,
1024, 2048, 3072, 4000,
};
static unsigned long long stop_watch()
{
struct timespec t;
t.tv_sec = t.tv_nsec = 0;
clock_gettime(CLOCK_MONOTONIC, &t);
return t.tv_sec*1000000000ULL + t.tv_nsec;
}
int main()
{
char *mem = malloc((N_PAGES+1) * 4096);
intptr_t *p;
int i;
unsigned int j;
/* Align to page start */
mem = (char *) ((intptr_t) (mem + 4096) & ~0xfff);
for (j = 0; j < sizeof(numPagesList)/sizeof(int); j++) {
int numPages = numPagesList[j];
int pageIdx = 0;
int entryOffset = 0;
/*
* page 0 page 1 page 2 .... page N
* ------ ------ ------ ------
* word 0 -> word 0 -> word 0 -> .... -> word 0 -> (page 0/word 0)
* : : : : :
* word 1023 word 1023 word 1023 : word 1023
*/
for (i = 0; i < numPages; i++) {
int nextPageIdx = (pageIdx + 1) % numPages;
/* Looks like spread the pointer across cache lines introduce noise
* to get to the asymptote
* int nextEntryOffset = (entryOffset + 32) % 1024;
*/
int nextEntryOffset = entryOffset;
if (i != numPages -1) {
*(intptr_t *) (mem + 4096 * pageIdx + entryOffset) =
(intptr_t) (mem + 4096 * nextPageIdx + nextEntryOffset);
} else {
/* Last page - form the cycle */
*(intptr_t *) (mem + 4096 * pageIdx + entryOffset) =
(intptr_t) &mem[0];
}
pageIdx = nextPageIdx;
entryOffset = nextEntryOffset;
}
/* Starting point of the pointer chase */
p = (intptr_t *) &mem[0];
/* Warmup (ie pre-thrash the memory system */
for (i = 0; i < WARMUP; i++) {
p = (intptr_t *) *p;
}
/* Real work */
unsigned long long t0 = stop_watch();
for (i = 0; i < WORKLOAD; i++) {
p = (intptr_t *) *p;
}
unsigned long long t1 = stop_watch();
/* To keep p from being optimized by gcc */
if (p)
printf("%d, %f\n", numPages, (float) (t1 - t0) / WORKLOAD);
}
return 0;
}