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| author | Thomas Gleixner <tglx@linutronix.de> | 2022-04-15 22:19:59 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2022-04-27 21:22:19 +0300 |
| commit | bb6e89df9028b2fab0ce6ac71cd9ef25b6ada32d (patch) | |
| tree | 5440e10c14c8d2f32939a982f348ae83564b7b19 /arch/x86/include/asm/topology.h | |
| parent | 73a5fa7d51366a549a9f2e3ee875ae51aa0b5580 (diff) | |
| download | linux-bb6e89df9028b2fab0ce6ac71cd9ef25b6ada32d.tar.xz | |
x86/aperfmperf: Make parts of the frequency invariance code unconditional
The frequency invariance support is currently limited to x86/64 and SMP,
which is the vast majority of machines.
arch_scale_freq_tick() is called every tick on all CPUs and reads the APERF
and MPERF MSRs. The CPU frequency getters function do the same via dedicated
IPIs.
While it could be argued that on systems where frequency invariance support
is disabled (32bit, !SMP) the per tick read of the APERF and MPERF MSRs can
be avoided, it does not make sense to keep the extra code and the resulting
runtime issues of mass IPIs around.
As a first step split out the non frequency invariance specific
initialization code and the read MSR portion of arch_scale_freq_tick(). The
rest of the code is still conditional and guarded with a static key.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20220415161206.761988704@linutronix.de
Diffstat (limited to 'arch/x86/include/asm/topology.h')
| -rw-r--r-- | arch/x86/include/asm/topology.h | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h index cc317077e73e..1b2553dd3c64 100644 --- a/arch/x86/include/asm/topology.h +++ b/arch/x86/include/asm/topology.h @@ -217,13 +217,9 @@ extern void arch_scale_freq_tick(void); extern void arch_set_max_freq_ratio(bool turbo_disabled); extern void freq_invariance_set_perf_ratio(u64 ratio, bool turbo_disabled); -extern void bp_init_freq_invariance(void); -extern void ap_init_freq_invariance(void); #else static inline void arch_set_max_freq_ratio(bool turbo_disabled) { } static inline void freq_invariance_set_perf_ratio(u64 ratio, bool turbo_disabled) { } -static inline void bp_init_freq_invariance(void) { } -static inline void ap_init_freq_invariance(void) { } #endif #ifdef CONFIG_ACPI_CPPC_LIB |