The following commit has been merged into the sched/core branch of tip: Commit-ID: 3149cd55302748df771dc1c8c10f34b1cbce88ed Gitweb: https://git.kernel.org/tip/3149cd55302748df771dc1c8c10f34b1cbce88ed Author: Giovanni Gherdovich <ggherdov...@suse.cz> AuthorDate: Thu, 12 Nov 2020 19:26:14 +01:00 Committer: Ingo Molnar <mi...@kernel.org> CommitterDate: Fri, 11 Dec 2020 10:30:23 +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 <ggherdov...@suse.cz> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Ingo Molnar <mi...@kernel.org> Link: https://lkml.kernel.org/r/20201112182614.10700-4-ggherdov...@suse.cz --- 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"); }
