int perfmon_open_event(const struct core_set *cset, struct perfmon_session *ps,
const struct perfmon_event *pev)
{
ERRSTACK(1);
int i;
struct perfmon_alloc *pa = perfmon_create_alloc(pev);
if (waserror()) {
perfmon_destroy_alloc(pa);
nexterror();
}
smp_do_in_cores(cset, perfmon_do_cores_alloc, pa);
for (i = 0; i < num_cores; i++) {
if (core_set_getcpu(cset, i)) {
counter_t ccno = pa->cores_counters[i];
if (unlikely(ccno < 0)) {
perfmon_destroy_alloc(pa);
return (int) ccno;
}
}
}
/* The perfmon_alloc data structure will not be visible to userspace,
* until the perfmon_install_session_alloc() completes, and at that
* time the smp_do_in_cores(perfmon_do_cores_alloc) will have run on
* all cores.
* The perfmon_alloc data structure will never be changed once published.
*/
i = perfmon_install_session_alloc(ps, pa);
poperror();
return i;
}
void smp_do_in_cores(const struct core_set *cset, void (*func)(void *),
void *opaque)
{
int cpu = core_id();
struct all_cpu_work acw;
memset(&acw, 0, sizeof(acw));
completion_init(&acw.comp, core_set_remote_count(cset));
acw.func = func;
acw.opaque = opaque;
for (int i = 0; i < num_cores; i++) {
if (core_set_getcpu(cset, i)) {
if (i == cpu)
func(opaque);
else
send_kernel_message(i, smp_do_core_work, (long) &acw, 0, 0,
KMSG_ROUTINE);
}
}
completion_wait(&acw.comp);
}
