diff mbox series

[08/10] x86/aperfmperf: Store aperf/mperf data for cpu frequency reads

Message ID 20220415161206.817702355@linutronix.de
State Accepted
Commit cd8c0e142daf9de9ce594e61b75509b0af7bfb26
Headers show
Series x86/cpu: Consolidate APERF/MPERF code | expand

Commit Message

Thomas Gleixner April 15, 2022, 7:20 p.m. UTC 
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: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/kernel/cpu/aperfmperf.c |   14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)
diff mbox series

Patch

--- a/arch/x86/kernel/cpu/aperfmperf.c
+++ b/arch/x86/kernel/cpu/aperfmperf.c
@@ -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);
 }