FAILED: patch "[PATCH] sched/topology: Fix building of overlapping sched-groups" failed to apply to 3.18-stable tree
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[email protected]
maintainerThe patch below does not apply to the 3.18-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
Quoted 1 line
From
0372dd2736e02672ac6e189c31f7d8c02ad543cdMon Sep 17 00:00:00 2001
From: Peter Zijlstra <[email protected]>
Date: Fri, 14 Apr 2017 17:24:02 +0200
Subject: [PATCH] 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 10Where (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)
kernel/sched/topology.c +1 -1
@@ -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))