Commit:
cebf15eb09 ("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>
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