From: Viresh Kumar <viresh.kumar@linaro.org>
To: Ionela Voinescu <ionela.voinescu@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH V2 2/2] arm64: topology: Reorder init_amu_fie() a bit
Date: Thu, 10 Dec 2020 21:59:23 +0530 [thread overview]
Message-ID: <202f775d57bd143602f9100ba3d9619d15d43409.1607617625.git.viresh.kumar@linaro.org> (raw)
In-Reply-To: <5f85c2ddf7aa094d7d2ebebe8426f84fad0a99b7.1607617625.git.viresh.kumar@linaro.org>
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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next prev parent reply other threads:[~2020-12-10 16:31 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-10 16:29 [PATCH V2 1/2] arm64: topology: Avoid the have_policy check Viresh Kumar
2020-12-10 16:29 ` Viresh Kumar [this message]
2020-12-14 14:00 ` [PATCH V2 2/2] arm64: topology: Reorder init_amu_fie() a bit Ionela Voinescu
2020-12-15 4:49 ` Viresh Kumar
2020-12-14 12:57 ` [PATCH V2 1/2] arm64: topology: Avoid the have_policy check Ionela Voinescu
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