sched/x86: Fix up typo in topology detection
authorDave Hansen <dave.hansen@linux.intel.com>
Tue, 30 Sep 2014 21:45:46 +0000 (14:45 -0700)
committerIngo Molnar <mingo@kernel.org>
Fri, 3 Oct 2014 03:46:52 +0000 (05:46 +0200)
commit728e5653e6fdb2a0892e94a600aef8c9a036c7eb
treebb71ced94543500b38e2591e5d451cb66b2f7d4f
parentcebf15eb09a2fd2fa73ee4faa9c4d2f813cf0f09
sched/x86: Fix up typo in topology detection

Commit:

  cebf15eb09a2 ("x86, sched: Add new topology for multi-NUMA-node CPUs")

some code to try to detect the situation where we have a NUMA node
inside of the "DIE" sched domain.

It detected this by looking for cpus which match_die() but do not match
NUMA nodes via topology_same_node().

I wrote it up as:

if (match_die(c, o) == !topology_same_node(c, o))

which actually seemed to work some of the time, albiet
accidentally.

It should have been doing an &&, not an ==.

This code essentially chopped off the "DIE" domain on one of
Andrew Morton's systems.  He reported that this patch fixed his
issue.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Lan Tianyu <tianyu.lan@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Link: http://lkml.kernel.org/r/20140930214546.FD481CFF@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/kernel/smpboot.c