From: Srivatsa Vaddagiri <vatsa@in.ibm.com> Patch below fixes a cpu_up race in PPC64. Signed-off-by : Srivatsa Vaddagiri <vatsa@in.ibm.com> Signed-off-by : Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> --- 25-akpm/arch/ppc64/kernel/smp.c | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletion(-) diff -puN arch/ppc64/kernel/smp.c~ppc64-fix-cpu_up-race arch/ppc64/kernel/smp.c --- 25/arch/ppc64/kernel/smp.c~ppc64-fix-cpu_up-race 2004-08-01 23:00:01.240344376 -0700 +++ 25-akpm/arch/ppc64/kernel/smp.c 2004-08-01 23:00:01.244343768 -0700 @@ -935,7 +935,11 @@ int __devinit __cpu_up(unsigned int cpu) if (smp_ops->give_timebase) smp_ops->give_timebase(); - cpu_set(cpu, cpu_online_map); + + /* Wait until cpu puts itself in the online map */ + while (!cpu_online(cpu)) + cpu_relax(); + return 0; } @@ -971,6 +975,10 @@ int __devinit start_secondary(void *unus #endif #endif + spin_lock(&call_lock); + cpu_set(cpu, cpu_online_map); + spin_unlock(&call_lock); + local_irq_enable(); return cpu_idle(NULL); _