s390/smp: wait until secondaries are active & online

This is the s390 version of 875ebe940d ("powerpc/smp: Wait until secondaries
are active & online").
The race described in length within the commit message is also possible on s390
and every other architecture. So fix this race on s390 as well.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2015-03-30 12:51:42 +02:00 committed by Martin Schwidefsky
parent d744194956
commit a1307bba1a

View File

@ -818,7 +818,8 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle)
pcpu_prepare_secondary(pcpu, cpu);
pcpu_attach_task(pcpu, tidle);
pcpu_start_fn(pcpu, smp_start_secondary, NULL);
while (!cpu_online(cpu))
/* Wait until cpu puts itself in the online & active maps */
while (!cpu_online(cpu) || !cpu_active(cpu))
cpu_relax();
return 0;
}