Commen=
t # 2
on bug 10969=
5
from Ahzo@tutanota.co=
m
To check for the availability of the syscall, one can try it i=
n a child process
and see if the child is terminated by a signal, e.g. like this:
#include <stdbool.h>
#include <unistd.h>
#include <sys/resource.h>
#include <sys/syscall.h>
#include <sys/wait.h>
static bool
can_set_affinity()
{
pid_t pid =3D fork();
int status =3D 0;
if (!pid) {
/* Disable coredumps, because a SIGSYS crash is expected. */
struct rlimit limit =3D { 0 };
limit.rlim_cur =3D 1;
limit.rlim_max =3D 1;
setrlimit(RLIMIT_CORE, &limit);
/* Test the syscall in the child process. */
syscall(SYS_sched_setaffinity, 0, 0, 0);
_exit(0);
} else if (pid < 0) {
return false;
}
if (waitpid(pid, &status, 0) < 0) {
return false;
}
if (WIFSIGNALED(status)) {
/* The child process was terminated by a signal,
* thus the syscall cannot be used.
*/
return false;
}
return true;
}