On 17/03/2023 00:57, Hillf Danton wrote: > On 16 Mar 2023 13:28:18 +0100 Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> >> On 15/03/2023 17:49, Krzysztof Kozlowski wrote: >>> Qualcomm cpufreq driver configures interrupts with affinity to each >>> cluster, e.g. dcvsh-irq-0, dcvsh-irq-4 and dcvsh-irq-7 on SM8250. >>> Triggered interrupt will schedule delayed work, but, since workqueue >>> prefers local CPUs, it might get executed on a CPU dedicated to realtime >>> tasks causing unexpected latencies in realtime workload. >>> >>> Use unbound workqueue for such case. This might come with performance >>> or energy penalty, e.g. because of cache miss or when other CPU is >>> sleeping. >>> >>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> >>> --- >>> drivers/cpufreq/qcom-cpufreq-hw.c | 11 ++++++++++- >> >> Let me also paste impact of this patch - rtla osnoise on entirely idle >> system (cores 2-7 isolated for Realtime): > > Are cores 2-7 the non-housekeeping CPUs[1]? Yes, since their are isolated for Realtime this is synonymous. > > [1] https://lore.kernel.org/lkml/20230223150624.GA29739@xxxxxx/ Best regards, Krzysztof
