Messages in this thread Patch in this message | | | From | Viresh Kumar <> | Subject | [PATCH V2 2/2] arm64: topology: Reorder init_amu_fie() a bit | Date | Thu, 10 Dec 2020 21:59:23 +0530 |
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This patch does a couple of optimizations in init_amu_fie(), like early exits from paths where we don't need to continue any further, moving the calls to topology_scale_freq_invariant() just when we need them, instead of at the top of the routine, and avoiding calling it for the third time.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- V2: - The enable/disable dance is actually required, just made a bunch of other optimizations to make it look better.
arch/arm64/kernel/topology.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-)
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index ebadc73449f9..1ebdb667f0d1 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -221,7 +221,7 @@ static DEFINE_STATIC_KEY_FALSE(amu_fie_key); static int __init init_amu_fie(void) { - bool invariance_status = topology_scale_freq_invariant(); + bool prev, now; cpumask_var_t valid_cpus; int ret = 0; int cpu; @@ -249,18 +249,24 @@ static int __init init_amu_fie(void) if (cpumask_equal(valid_cpus, cpu_present_mask)) cpumask_copy(amu_fie_cpus, cpu_present_mask); - if (!cpumask_empty(amu_fie_cpus)) { - pr_info("CPUs[%*pbl]: counters will be used for FIE.", - cpumask_pr_args(amu_fie_cpus)); - static_branch_enable(&amu_fie_key); - } + if (cpumask_empty(amu_fie_cpus)) + goto free_valid_mask; + + prev = topology_scale_freq_invariant(); + static_branch_enable(&amu_fie_key); + now = topology_scale_freq_invariant(); /* * If the system is not fully invariant after AMU init, disable * partial use of counters for frequency invariance. */ - if (!topology_scale_freq_invariant()) + if (!now) { static_branch_disable(&amu_fie_key); + goto free_valid_mask; + } + + pr_info("CPUs[%*pbl]: counters will be used for FIE.", + cpumask_pr_args(amu_fie_cpus)); /* * Task scheduler behavior depends on frequency invariance support, @@ -268,7 +274,7 @@ static int __init init_amu_fie(void) * a result of counter initialisation and use, retrigger the build of * scheduling domains to ensure the information is propagated properly. */ - if (invariance_status != topology_scale_freq_invariant()) + if (prev != now) rebuild_sched_domains_energy(); free_valid_mask: -- 2.25.0.rc1.19.g042ed3e048af
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