Commit cd8c0e14 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

x86/aperfmperf: Store aperf/mperf data for cpu frequency reads 



Now that the MSR readout is unconditional, store the results in the per CPU
data structure along with a jiffies timestamp for the CPU frequency readout
code.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20220415161206.817702355@linutronix.de
parent bb6e89df

arch/x86/kernel/cpu/aperfmperf.c

+13 −1
Original line number Diff line number Diff line
@@ -24,11 +24,17 @@ 
#include "cpu.h"



struct aperfmperf {

	seqcount_t	seq;

	unsigned long	last_update;

	u64		acnt;

	u64		mcnt;

	u64		aperf;

	u64		mperf;

};



static DEFINE_PER_CPU_SHARED_ALIGNED(struct aperfmperf, cpu_samples);

static DEFINE_PER_CPU_SHARED_ALIGNED(struct aperfmperf, cpu_samples) = {

	.seq = SEQCNT_ZERO(cpu_samples.seq)

};



struct aperfmperf_sample {

	unsigned int	khz;
@@ -515,6 +521,12 @@ void arch_scale_freq_tick(void) 
	s->aperf = aperf;

	s->mperf = mperf;



	raw_write_seqcount_begin(&s->seq);

	s->last_update = jiffies;

	s->acnt = acnt;

	s->mcnt = mcnt;

	raw_write_seqcount_end(&s->seq);



	scale_freq_tick(acnt, mcnt);

}