Hi,

According to man clock_getcpuclockid() should return ESRCH if there is no process with the ID pid.

diff --git a/src/time/clock_getcpuclockid.c b/src/time/clock_getcpuclockid.c
--- a/src/time/clock_getcpuclockid.c
+++ b/src/time/clock_getcpuclockid.c
@@ -8,6 +8,7 @@ int clock_getcpuclockid(pid_t pid, clockid_t *clk)
        struct timespec ts;
        clockid_t id = (-pid-1)*8U + 2;
        int ret = __syscall(SYS_clock_getres, id, &ts);
+       if (ret == -EINVAL) ret = -ESRCH;
        if (ret) return -ret;
        *clk = id;
        return 0

The same behaviour is used in glibc:
https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/clock_getcpuclockid.c;h=5534127ed703a3931f22af48da02e2b8f2dc39a5;hb=HEAD#l49

--
Best regards,
Eugene