mirrors/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-02-23 21:11:51 -05:00
Code Issues Packages Projects Releases Wiki Activity

arm64: Update AMU-based freq scale factor on entering idle

Browse Source 
Now that the frequency scale factor has been activated for retrieving
current frequency on a given CPU, trigger its update upon entering
idle. This will, to an extent, allow querying last known frequency
in a non-invasive way. It will also improve the frequency scale factor
accuracy when a CPU entering idle did not receive a tick for a while.
As a consequence, for idle cores, the reported frequency will be the
last one observed before entering the idle state.

Suggested-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com>
Signed-off-by: Beata Michalska <beata.michalska@arm.com>
Reviewed-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com>
Reviewed-by: Sumit Gupta <sumitg@nvidia.com>
Link: https://lore.kernel.org/r/20250131162439.3843071-5-beata.michalska@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Beata Michalska
2025-01-31 16:24:39 +00:00
committed by Catalin Marinas
parent 16d1e27475
commit 39b1997498
1 changed files with 13 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
arch/arm64/kernel/topology.c
View File

@@ -213,6 +213,19 @@ static __always_inline bool amu_fie_cpu_supported(unsigned int cpu)
cpumask_test_cpu(cpu, amu_fie_cpus);
}
void arch_cpu_idle_enter(void)
{
unsigned int cpu = smp_processor_id();
if (!amu_fie_cpu_supported(cpu))
return;
/* Kick in AMU update but only if one has not happened already */
if (housekeeping_cpu(cpu, HK_TYPE_TICK) &&
time_is_before_jiffies(per_cpu(cpu_amu_samples.last_scale_update, cpu)))
amu_scale_freq_tick();
}
#define AMU_SAMPLE_EXP_MS 20
int arch_freq_get_on_cpu(int cpu)