David Miller wrote:
There is absolutely no connection between virtual cpu numbers
and the hierarchy in which they sit in the cores and higher
level hierarchy of the processor. So you can't just say
(cpu_id / 4) is the core number or anything like that.
You must use the machine description to determine this kind of
information, just as we do in arch/sparc/kernel/mdesc.c to figure out
the CPU scheduler grouping maps. (see mark_proc_ids() and
mark_core_ids())
Thanks for pointing me in this direction. mark_proc_ids() and
mark_core_ids() sets the core_id and proc_id members in the per
cpu __cpu_data. Looks like I can use cpu_data() to figure out
the CPU distribution.
As a side note, here's a dump of cpu_data() on a 2 way T5440.
There's a hole between 48 and 71.
[714162.134215] Brought up 96 CPUs
[714162.135440] CPU 0: node=0 core_id=1 proc_id=0
[714162.135452] CPU 1: node=0 core_id=1 proc_id=0
[714162.135464] CPU 2: node=0 core_id=1 proc_id=0
[714162.135475] CPU 3: node=0 core_id=1 proc_id=0
[714162.135487] CPU 4: node=0 core_id=1 proc_id=1
[714162.135498] CPU 5: node=0 core_id=1 proc_id=1
[714162.135509] CPU 6: node=0 core_id=1 proc_id=1
[714162.135521] CPU 7: node=0 core_id=1 proc_id=1
[714162.135532] CPU 8: node=0 core_id=2 proc_id=2
[714162.135544] CPU 9: node=0 core_id=2 proc_id=2
[714162.135555] CPU 10: node=0 core_id=2 proc_id=2
...
[714162.135961] CPU 45: node=0 core_id=6 proc_id=11
[714162.135973] CPU 46: node=0 core_id=6 proc_id=11
[714162.135984] CPU 47: node=0 core_id=6 proc_id=11
[714162.135996] CPU 72: node=1 core_id=7 proc_id=12
[714162.136008] CPU 73: node=1 core_id=7 proc_id=12
[714162.136019] CPU 74: node=1 core_id=7 proc_id=12
[714162.136031] CPU 75: node=1 core_id=7 proc_id=12
[714162.136043] CPU 76: node=1 core_id=7 proc_id=13
...
[714162.136554] CPU 119: node=1 core_id=12 proc_id=23
Regards,
Hong
diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
index 54906aa..7fa909f 100644
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -1353,8 +1353,20 @@ void __cpu_die(unsigned int cpu)
}
#endif
+static void dump_cpu_data(void)
+{
+ int i;
+
+ for_each_online_cpu(i) {
+ printk(KERN_DEBUG "CPU %i: node=%i core_id=%i proc_id=%i\n",
+ i, cpu_to_node(i),
+ cpu_data(i).core_id, cpu_data(i).proc_id);
+ }
+}
+
void __init smp_cpus_done(unsigned int max_cpus)
{
+ dump_cpu_data();
}
void smp_send_reschedule(int cpu)
