The following commit has been merged into the sched/core branch of tip:
Commit-ID: 24f326686c925a848d603a2c22f1f6ed1b7786e2
Gitweb: https://git.kernel.org/tip/24f326686c925a848d603a2c22f1f6ed1b7786e2
Author: Giovanni Gherdovich <ggherdovich@xxxxxxx>
AuthorDate: Thu, 12 Nov 2020 19:26:14 +01:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Thu, 03 Dec 2020 10:00:35 +01:00
x86: Print ratio freq_max/freq_base used in frequency invariance calculations
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@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20201112182614.10700-4-ggherdovich@xxxxxxx
---
arch/x86/kernel/smpboot.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index c5dd5f6..3577bb7 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) {
init_counter_refs();
static_branch_enable(&arch_scale_freq_key);
+ 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");
}
|