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perf/arm-cmn: Optimise DTC counter accesses
authorRobin Murphy <robin.murphy@arm.com>
Fri, 3 Dec 2021 11:44:57 +0000 (11:44 +0000)
committerWill Deacon <will@kernel.org>
Tue, 14 Dec 2021 12:09:28 +0000 (12:09 +0000)
commit4f2c3872dde55090bf39e1f12a8517a32b6cd048
treec7389629a8050b79f33185c7fdf6eb48f0fa8c8c
parent847eef94e6327dd7690bfac0bd3a81a7ba6aa1ee
perf/arm-cmn: Optimise DTC counter accesses

In cases where we do know which DTC domain a node belongs to, we can
skip initialising or reading the global count in DTCs where we know
it won't change. The machinery to achieve that is mostly in place
already, so finish hooking it up by converting the vestigial domain
tracking to propagate suitable bitmaps all the way through to events.

Note that this does not allow allocating such an unused counter to a
different event on that DTC, because that is a flippin' nightmare.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/51d930fd945ef51c81f5889ccca055c302b0a1d0.1638530442.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
drivers/perf/arm-cmn.c