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| author | Peter Zijlstra <peterz@infradead.org> | 2017-04-14 17:24:02 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-05-15 10:15:23 +0200 |
| commit | 0372dd2736e02672ac6e189c31f7d8c02ad543cd (patch) | |
| tree | 9a673fd5078d02d1deb55424e5d2a4efb2bf08fa /kernel/sched/topology.c | |
| parent | c743f0a5c50f2fcbc628526279cfa24f3dabe182 (diff) | |
| download | blackbird-obmc-linux-0372dd2736e02672ac6e189c31f7d8c02ad543cd.tar.gz blackbird-obmc-linux-0372dd2736e02672ac6e189c31f7d8c02ad543cd.zip | |
sched/topology: Fix building of overlapping sched-groups
When building the overlapping groups, we very obviously should start
with the previous domain of _this_ @cpu, not CPU-0.
This can be readily demonstrated with a topology like:
node 0 1 2 3
0: 10 20 30 20
1: 20 10 20 30
2: 30 20 10 20
3: 20 30 20 10
Where (for example) CPU1 ends up generating the following nonsensical groups:
[] CPU1 attaching sched-domain:
[] domain 0: span 0-2 level NUMA
[] groups: 1 2 0
[] domain 1: span 0-3 level NUMA
[] groups: 1-3 (cpu_capacity = 3072) 0-1,3 (cpu_capacity = 3072)
Where the fact that domain 1 doesn't include a group with span 0-2 is
the obvious fail.
With patch this looks like:
[] CPU1 attaching sched-domain:
[] domain 0: span 0-2 level NUMA
[] groups: 1 0 2
[] domain 1: span 0-3 level NUMA
[] groups: 0-2 (cpu_capacity = 3072) 0,2-3 (cpu_capacity = 3072)
Debugged-by: Lauro Ramos Venancio <lvenanci@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: e3589f6c81e4 ("sched: Allow for overlapping sched_domain spans")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/topology.c')
| -rw-r--r-- | kernel/sched/topology.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index d786d45c44d9..921dedde2ee1 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -566,7 +566,7 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu) cpumask_clear(covered); - for_each_cpu(i, span) { + for_each_cpu_wrap(i, span, cpu) { struct cpumask *sg_span; if (cpumask_test_cpu(i, covered)) |
