A single fix for the interrupt affinity spreading logic to take into
account that there can be an imbalance between present and possible CPUs,
which causes already assigned bits to be overwritten.
genirq/affinity: Consider that CPUs on nodes can be unbalanced
If CPUs on a node are offline at boot time, the number of nodes is
different when building affinity masks for present cpus and when building
affinity masks for possible cpus. This causes the following problem:
In the case that the number of vectors is less than the number of nodes
there are cases where bits of masks for present cpus are overwritten when
building masks for possible cpus.
Fix this by excluding CPUs, which are not part of the current build mask
(present/possible).
[ tglx: Massaged changelog and added comment ]
Fixes: b82592199032 ("genirq/affinity: Spread IRQs to all available NUMA nodes")
Signed-off-by: Rei Yamamoto <yamamoto.rei@jp.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220331003309.10891-1-yamamoto.rei@jp.fujitsu.com
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