mirror of
https://github.com/rd-stuffs/msm-4.14.git
synced 2025-02-20 11:45:48 +08:00
In commit a21b0b354d4a ('perf: Introduce a flag to enable close-on-exec in perf_event_open()'), flag PERF_FLAG_FD_CLOEXEC was added to perf_event_open(2) syscall to allows userspace to atomically enable close-on-exec behavor when creating the file descriptor. This patch makes perf tools use the new flag if supported by the kernel, so that the event file descriptors got automatically closed if perf tool exec a sub-command. Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/1404160127-7475-1-git-send-email-ydroneaud@opteya.com Signed-off-by: Jiri Olsa <jolsa@kernel.org>
176 lines
3.1 KiB
C
176 lines
3.1 KiB
C
#include <unistd.h>
|
|
#include <stdlib.h>
|
|
#include <signal.h>
|
|
#include <sys/mman.h>
|
|
#include <linux/types.h>
|
|
#include "perf.h"
|
|
#include "debug.h"
|
|
#include "tests.h"
|
|
#include "cloexec.h"
|
|
|
|
#if defined(__x86_64__) || defined(__i386__)
|
|
|
|
static u64 rdpmc(unsigned int counter)
|
|
{
|
|
unsigned int low, high;
|
|
|
|
asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter));
|
|
|
|
return low | ((u64)high) << 32;
|
|
}
|
|
|
|
static u64 rdtsc(void)
|
|
{
|
|
unsigned int low, high;
|
|
|
|
asm volatile("rdtsc" : "=a" (low), "=d" (high));
|
|
|
|
return low | ((u64)high) << 32;
|
|
}
|
|
|
|
static u64 mmap_read_self(void *addr)
|
|
{
|
|
struct perf_event_mmap_page *pc = addr;
|
|
u32 seq, idx, time_mult = 0, time_shift = 0;
|
|
u64 count, cyc = 0, time_offset = 0, enabled, running, delta;
|
|
|
|
do {
|
|
seq = pc->lock;
|
|
barrier();
|
|
|
|
enabled = pc->time_enabled;
|
|
running = pc->time_running;
|
|
|
|
if (enabled != running) {
|
|
cyc = rdtsc();
|
|
time_mult = pc->time_mult;
|
|
time_shift = pc->time_shift;
|
|
time_offset = pc->time_offset;
|
|
}
|
|
|
|
idx = pc->index;
|
|
count = pc->offset;
|
|
if (idx)
|
|
count += rdpmc(idx - 1);
|
|
|
|
barrier();
|
|
} while (pc->lock != seq);
|
|
|
|
if (enabled != running) {
|
|
u64 quot, rem;
|
|
|
|
quot = (cyc >> time_shift);
|
|
rem = cyc & ((1 << time_shift) - 1);
|
|
delta = time_offset + quot * time_mult +
|
|
((rem * time_mult) >> time_shift);
|
|
|
|
enabled += delta;
|
|
if (idx)
|
|
running += delta;
|
|
|
|
quot = count / running;
|
|
rem = count % running;
|
|
count = quot * enabled + (rem * enabled) / running;
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
/*
|
|
* If the RDPMC instruction faults then signal this back to the test parent task:
|
|
*/
|
|
static void segfault_handler(int sig __maybe_unused,
|
|
siginfo_t *info __maybe_unused,
|
|
void *uc __maybe_unused)
|
|
{
|
|
exit(-1);
|
|
}
|
|
|
|
static int __test__rdpmc(void)
|
|
{
|
|
volatile int tmp = 0;
|
|
u64 i, loops = 1000;
|
|
int n;
|
|
int fd;
|
|
void *addr;
|
|
struct perf_event_attr attr = {
|
|
.type = PERF_TYPE_HARDWARE,
|
|
.config = PERF_COUNT_HW_INSTRUCTIONS,
|
|
.exclude_kernel = 1,
|
|
};
|
|
u64 delta_sum = 0;
|
|
struct sigaction sa;
|
|
|
|
sigfillset(&sa.sa_mask);
|
|
sa.sa_sigaction = segfault_handler;
|
|
sigaction(SIGSEGV, &sa, NULL);
|
|
|
|
fd = sys_perf_event_open(&attr, 0, -1, -1,
|
|
perf_event_open_cloexec_flag());
|
|
if (fd < 0) {
|
|
pr_err("Error: sys_perf_event_open() syscall returned "
|
|
"with %d (%s)\n", fd, strerror(errno));
|
|
return -1;
|
|
}
|
|
|
|
addr = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, 0);
|
|
if (addr == (void *)(-1)) {
|
|
pr_err("Error: mmap() syscall returned with (%s)\n",
|
|
strerror(errno));
|
|
goto out_close;
|
|
}
|
|
|
|
for (n = 0; n < 6; n++) {
|
|
u64 stamp, now, delta;
|
|
|
|
stamp = mmap_read_self(addr);
|
|
|
|
for (i = 0; i < loops; i++)
|
|
tmp++;
|
|
|
|
now = mmap_read_self(addr);
|
|
loops *= 10;
|
|
|
|
delta = now - stamp;
|
|
pr_debug("%14d: %14Lu\n", n, (long long)delta);
|
|
|
|
delta_sum += delta;
|
|
}
|
|
|
|
munmap(addr, page_size);
|
|
pr_debug(" ");
|
|
out_close:
|
|
close(fd);
|
|
|
|
if (!delta_sum)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int test__rdpmc(void)
|
|
{
|
|
int status = 0;
|
|
int wret = 0;
|
|
int ret;
|
|
int pid;
|
|
|
|
pid = fork();
|
|
if (pid < 0)
|
|
return -1;
|
|
|
|
if (!pid) {
|
|
ret = __test__rdpmc();
|
|
|
|
exit(ret);
|
|
}
|
|
|
|
wret = waitpid(pid, &status, 0);
|
|
if (wret < 0 || status)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif
|