Re: [PATCH v2 3/3] intel_pstate: Declare pid_params/pstate_funcs/hwp_active __read_mostly

From: Jisheng Zhang
Date: Mon Jun 27 2016 - 22:33:40 EST


Dear Rafael,

On Mon, 27 Jun 2016 10:29:54 -0700
Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote:

> On Mon, 2016-06-27 at 18:07 +0800, Jisheng Zhang wrote:
> > pid_params is written once by copy_pid_params() during
> > initialization,
> > and thereafter is mostly read by hot path intel_pstate_update_util().
> > The read of pid_params gets more after commit a4675fbc4a7a ("cpufreq:
> > intel_pstate: Replace timers with utilization update callbacks")
> >
> > pstate_funcs is written once by copy_cpu_funcs() during
> > initialization,
> > and thereafter is mostly read by hot path intel_pstate_update_util()
> >
> > hwp_active is written to once during initialization and thereafter is
> > mostly read by hot path intel_pstate_update_util().
> >
> > The fact that they are mostly read and not written to makes them
> > candidates for __read_mostly declarations.
> >
> > Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx>
> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>

oops, I missed Viresh's Ack in this patch, so can you please add the missing

Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

Sorry for inconvenience,
Jisheng

> > ---
> > Âdrivers/cpufreq/intel_pstate.c | 6 +++---
> > Â1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/cpufreq/intel_pstate.c
> > b/drivers/cpufreq/intel_pstate.c
> > index 861bcba..2eda50d 100644
> > --- a/drivers/cpufreq/intel_pstate.c
> > +++ b/drivers/cpufreq/intel_pstate.c
> > @@ -281,9 +281,9 @@ struct cpu_defaults {
> > Âstatic inline int32_t get_target_pstate_use_performance(struct
> > cpudata *cpu);
> > Âstatic inline int32_t get_target_pstate_use_cpu_load(struct cpudata
> > *cpu);
> > Â
> > -static struct pstate_adjust_policy pid_params;
> > -static struct pstate_funcs pstate_funcs;
> > -static int hwp_active;
> > +static struct pstate_adjust_policy pid_params __read_mostly;
> > +static struct pstate_funcs pstate_funcs __read_mostly;
> > +static int hwp_active __read_mostly;
> > Â
> > Â#ifdef CONFIG_ACPI
> > Âstatic bool acpi_ppc;