mirror of https://gitee.com/openkylin/linux.git
100 lines
2.2 KiB
C
100 lines
2.2 KiB
C
/*
|
|
* Strictly speaking, this is not a test. But it can report during test
|
|
* runs so relative performace can be measured.
|
|
*/
|
|
#define _GNU_SOURCE
|
|
#include <assert.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <time.h>
|
|
#include <unistd.h>
|
|
#include <linux/filter.h>
|
|
#include <linux/seccomp.h>
|
|
#include <sys/prctl.h>
|
|
#include <sys/syscall.h>
|
|
#include <sys/types.h>
|
|
|
|
#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
|
|
|
|
unsigned long long timing(clockid_t clk_id, unsigned long long samples)
|
|
{
|
|
pid_t pid, ret;
|
|
unsigned long long i;
|
|
struct timespec start, finish;
|
|
|
|
pid = getpid();
|
|
assert(clock_gettime(clk_id, &start) == 0);
|
|
for (i = 0; i < samples; i++) {
|
|
ret = syscall(__NR_getpid);
|
|
assert(pid == ret);
|
|
}
|
|
assert(clock_gettime(clk_id, &finish) == 0);
|
|
|
|
i = finish.tv_sec - start.tv_sec;
|
|
i *= 1000000000;
|
|
i += finish.tv_nsec - start.tv_nsec;
|
|
|
|
printf("%lu.%09lu - %lu.%09lu = %llu\n",
|
|
finish.tv_sec, finish.tv_nsec,
|
|
start.tv_sec, start.tv_nsec,
|
|
i);
|
|
|
|
return i;
|
|
}
|
|
|
|
unsigned long long calibrate(void)
|
|
{
|
|
unsigned long long i;
|
|
|
|
printf("Calibrating reasonable sample size...\n");
|
|
|
|
for (i = 5; ; i++) {
|
|
unsigned long long samples = 1 << i;
|
|
|
|
/* Find something that takes more than 5 seconds to run. */
|
|
if (timing(CLOCK_REALTIME, samples) / 1000000000ULL > 5)
|
|
return samples;
|
|
}
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
struct sock_filter filter[] = {
|
|
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
|
|
};
|
|
struct sock_fprog prog = {
|
|
.len = (unsigned short)ARRAY_SIZE(filter),
|
|
.filter = filter,
|
|
};
|
|
long ret;
|
|
unsigned long long samples;
|
|
unsigned long long native, filtered;
|
|
|
|
if (argc > 1)
|
|
samples = strtoull(argv[1], NULL, 0);
|
|
else
|
|
samples = calibrate();
|
|
|
|
printf("Benchmarking %llu samples...\n", samples);
|
|
|
|
native = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples;
|
|
printf("getpid native: %llu ns\n", native);
|
|
|
|
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
|
|
assert(ret == 0);
|
|
|
|
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
|
|
assert(ret == 0);
|
|
|
|
filtered = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples;
|
|
printf("getpid RET_ALLOW: %llu ns\n", filtered);
|
|
|
|
printf("Estimated seccomp overhead per syscall: %llu ns\n",
|
|
filtered - native);
|
|
|
|
if (filtered == native)
|
|
printf("Trying running again with more samples.\n");
|
|
|
|
return 0;
|
|
}
|