[v4,3/3] x86: Print ratio freq_max/freq_base used in frequency invariance calculations
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Message ID 20201112182614.10700-4-ggherdovich@suse.cz
State New, archived
Headers show
  • Add support for frequency invariance to AMD EPYC Zen2
Related show

Commit Message

Giovanni Gherdovich Nov. 12, 2020, 6:26 p.m. UTC
The value freq_max/freq_base is a fundamental component of frequency
invariance calculations. It may come from a variety of sources such as MSRs
or ACPI data, tracking it down when troubleshooting a system could be
non-trivial. It is worth saving it in the kernel logs.

 # dmesg | grep 'Estimated ratio of average max'
 [   14.024036] smpboot: Estimated ratio of average max frequency by base frequency (times 1024): 1289

Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
 arch/x86/kernel/smpboot.c | 1 +
 1 file changed, 1 insertion(+)

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diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index c5dd5f6199d9..3577bb756d64 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -2110,6 +2110,7 @@  static void init_freq_invariance(bool secondary, bool cppc_ready)
 	if (ret) {
+		pr_info("Estimated ratio of average max frequency by base frequency (times 1024): %llu\n", arch_max_freq_ratio);
 	} else {
 		pr_debug("Couldn't determine max cpu frequency, necessary for scale-invariant accounting.\n");