Commit
316ad248307fb ("sched/x86: Rewrite set_cpu_sibling_map()")
broke the booted_cores accounting.
The problem is that the booted_cores accounting needs all the
sibling links set up. So restore the second loop and add a comment as
to why its needed.
On qemu booted with -smp sockets=1,cores=2,threads=2;
Before:
$ grep cores /proc/cpuinfo
cpu cores : 2
cpu cores : 1
cpu cores : 4
cpu cores : 3
With the patch:
$ grep cores /proc/cpuinfo
cpu cores : 2
cpu cores : 2
cpu cores : 2
cpu cores : 2
Reported-by: Prarit Bhargava <prarit@redhat.com>
Reported-by: Borislav Petkov <bp@amd64.org>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120531073738.GH7511@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
if ((i == cpu) || (has_mc && match_llc(c, o)))
link_mask(llc_shared, cpu, i);
+ }
+
+ /*
+ * This needs a separate iteration over the cpus because we rely on all
+ * cpu_sibling_mask links to be set-up.
+ */
+ for_each_cpu(i, cpu_sibling_setup_mask) {
+ o = &cpu_data(i);
+
if ((i == cpu) || (has_mc && match_mc(c, o))) {
link_mask(core, cpu, i);