diff options
| author | Giovanni Gherdovich <ggherdovich@suse.cz> | 2020-01-22 16:16:15 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-01-28 21:37:04 +0100 |
| commit | eacf0474aec8bdccdc7f19386319127c67be3588 (patch) | |
| tree | efb7b1b70d507ec9ccaa00f07a64fe5a0d7c3a11 /arch/x86/kernel/smpboot.c | |
| parent | 8bea0dfb4a820ae063568a87cc2e7d8f587377af (diff) | |
x86, sched: Add support for frequency invariance on ATOM_GOLDMONT*
The scheduler needs the ratio freq_curr/freq_max for frequency-invariant
accounting. On GOLDMONT (aka Apollo Lake), GOLDMONT_D (aka Denverton) and
GOLDMONT_PLUS CPUs (aka Gemini Lake) set freq_max to the highest frequency
reported by the CPU.
The encoding of turbo ratios for GOLDMONT* is identical to the one for
SKYLAKE_X, but we treat the Atom case apart because we want to set freq_max to
a higher value, thus the ratio freq_curr/freq_max to be lower, leading to more
conservative frequency selections (favoring power efficiency).
Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20200122151617.531-5-ggherdovich@suse.cz
Diffstat (limited to 'arch/x86/kernel/smpboot.c')
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 8cb3113377a9..3e32d620f1fb 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1795,6 +1795,10 @@ void native_play_dead(void) * which would ignore the entire turbo range (a conspicuous part, making * freq_curr/freq_max always maxed out). * + * An exception to the heuristic above is the Atom uarch, where we choose the + * highest turbo level for freq_max since Atom's are generally oriented towards + * power efficiency. + * * Setting freq_max to anything less than the 1C turbo ratio makes the ratio * freq_curr / freq_max to eventually grow >1, in which case we clip it to 1. */ @@ -1937,18 +1941,18 @@ static bool intel_set_max_freq_ratio(void) /* * TODO: add support for: * - * - Atom Goldmont * - Atom Silvermont */ u64 base_freq = 1, turbo_freq = 1; - if (x86_match_cpu(has_glm_turbo_ratio_limits)) - return false; - if (turbo_disabled()) goto out; + if (x86_match_cpu(has_glm_turbo_ratio_limits) && + skx_set_max_freq_ratio(&base_freq, &turbo_freq, 1)) + goto out; + if (knl_set_max_freq_ratio(&base_freq, &turbo_freq, 1)) goto out; |