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// SPDX-License-Identifier: GPL-2.0
#include "tests/tests.h"
#include "cloexec.h"
#include "debug.h"
#include "evlist.h"
#include "evsel.h"
#include "arch-tests.h"
#include <internal/lib.h> // page_size
#include <signal.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include <errno.h>
#include <string.h>
static pid_t spawn(void)
{
pid_t pid;
pid = fork();
if (pid)
return pid;
while(1)
sleep(5);
return 0;
}
/*
* Create an event group that contains both a sampled hardware
* (cpu-cycles) and software (intel_cqm/llc_occupancy/) event. We then
* wait for the hardware perf counter to overflow and generate a PMI,
* which triggers an event read for both of the events in the group.
*
* Since reading Intel CQM event counters requires sending SMP IPIs, the
* CQM pmu needs to handle the above situation gracefully, and return
* the last read counter value to avoid triggering a WARN_ON_ONCE() in
* smp_call_function_many() caused by sending IPIs from NMI context.
*/
int test__intel_cqm_count_nmi_context(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
struct evlist *evlist = NULL;
struct evsel *evsel = NULL;
struct perf_event_attr pe;
int i, fd[2], flag, ret;
size_t mmap_len;
void *event;
pid_t pid;
int err = TEST_FAIL;
flag = perf_event_open_cloexec_flag();
evlist = evlist__new();
if (!evlist) {
pr_debug("evlist__new failed\n");
return TEST_FAIL;
}
ret = parse_event(evlist, "intel_cqm/llc_occupancy/");
if (ret) {
pr_debug("parse_events failed, is \"intel_cqm/llc_occupancy/\" available?\n");
err = TEST_SKIP;
goto out;
}
evsel = evlist__first(evlist);
if (!evsel) {
pr_debug("evlist__first failed\n");
goto out;
}
memset(&pe, 0, sizeof(pe));
pe.size = sizeof(pe);
pe.type = PERF_TYPE_HARDWARE;
pe.config = PERF_COUNT_HW_CPU_CYCLES;
pe.read_format = PERF_FORMAT_GROUP;
pe.sample_period = 128;
pe.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_READ;
pid = spawn();
fd[0] = sys_perf_event_open(&pe, pid, -1, -1, flag);
if (fd[0] < 0) {
pr_debug("failed to open event\n");
goto out;
}
memset(&pe, 0, sizeof(pe));
pe.size = sizeof(pe);
pe.type = evsel->attr.type;
pe.config = evsel->attr.config;
fd[1] = sys_perf_event_open(&pe, pid, -1, fd[0], flag);
if (fd[1] < 0) {
pr_debug("failed to open event\n");
goto out;
}
/*
* Pick a power-of-two number of pages + 1 for the meta-data
* page (struct perf_event_mmap_page). See tools/perf/design.txt.
*/
mmap_len = page_size * 65;
event = mmap(NULL, mmap_len, PROT_READ, MAP_SHARED, fd[0], 0);
if (event == (void *)(-1)) {
pr_debug("failed to mmap %d\n", errno);
goto out;
}
sleep(1);
err = TEST_OK;
munmap(event, mmap_len);
for (i = 0; i < 2; i++)
close(fd[i]);
kill(pid, SIGKILL);
wait(NULL);
out:
evlist__delete(evlist);
return err;
}
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