From: Ionela Voinescu <ionela.voinescu@arm.com>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH V3 2/3] arm64: topology: Reorder init_amu_fie() a bit
Date: Tue, 15 Dec 2020 11:53:21 +0000 [thread overview]
Message-ID: <20201215115321.GA25331@arm.com> (raw)
In-Reply-To: <87d517c24630494afd9ba5769c2e2b10ee1d3f5d.1608010334.git.viresh.kumar@linaro.org>
On Tuesday 15 Dec 2020 at 11:04:15 (+0530), Viresh Kumar wrote:
> 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, avoid the
> enable/disable dance, 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>
> ---
> V3:
> - Skipped the enable/disable dance.
> - No need to call topology_scale_freq_invariant() multiple times.
>
> arch/arm64/kernel/topology.c | 27 ++++++++++++++-------------
> 1 file changed, 14 insertions(+), 13 deletions(-)
>
> diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
> index ebadc73449f9..57267d694495 100644
> --- a/arch/arm64/kernel/topology.c
> +++ b/arch/arm64/kernel/topology.c
> @@ -221,8 +221,8 @@ static DEFINE_STATIC_KEY_FALSE(amu_fie_key);
>
> static int __init init_amu_fie(void)
> {
> - bool invariance_status = topology_scale_freq_invariant();
> cpumask_var_t valid_cpus;
> + bool invariant;
> int ret = 0;
> int cpu;
>
> @@ -249,18 +249,19 @@ 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;
>
> - /*
> - * If the system is not fully invariant after AMU init, disable
> - * partial use of counters for frequency invariance.
> - */
> - if (!topology_scale_freq_invariant())
> - static_branch_disable(&amu_fie_key);
> + invariant = topology_scale_freq_invariant();
> +
> + /* We aren't fully invariant yet */
> + if (!invariant && !cpumask_equal(amu_fie_cpus, cpu_present_mask))
> + goto free_valid_mask;
> +
> + static_branch_enable(&amu_fie_key);
> +
> + 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 +269,7 @@ 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 (!invariant)
> rebuild_sched_domains_energy();
>
> free_valid_mask:
> --
> 2.25.0.rc1.19.g042ed3e048af
>
Looks good!
Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com>
next prev parent reply other threads:[~2020-12-15 11:54 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-15 5:34 [PATCH V3 1/3] arm64: topology: Avoid the have_policy check Viresh Kumar
2020-12-15 5:34 ` [PATCH V3 2/3] arm64: topology: Reorder init_amu_fie() a bit Viresh Kumar
2020-12-15 11:53 ` Ionela Voinescu [this message]
2020-12-15 5:34 ` [PATCH V3 3/3] arm64: topology: Make AMUs work with modular cpufreq drivers Viresh Kumar
2020-12-15 11:56 ` Ionela Voinescu
2020-12-16 0:03 ` Ionela Voinescu
2020-12-16 4:38 ` Viresh Kumar
2020-12-16 19:37 ` Ionela Voinescu
2020-12-17 10:50 ` Viresh Kumar
2021-01-08 9:44 ` Ionela Voinescu
2021-01-08 10:42 ` Ionela Voinescu
2021-01-08 11:03 ` Viresh Kumar
2020-12-17 7:57 ` [PATCH V3 1/3] arm64: topology: Avoid the have_policy check Viresh Kumar
2020-12-17 10:55 ` Catalin Marinas
2020-12-18 4:26 ` Viresh Kumar
2020-12-18 11:01 ` Catalin Marinas
2020-12-18 11:04 ` Viresh Kumar
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