Re: [PATCH v9 2/2] examples/l3fwd-power: add PM QoS configuration

["lihuisong (C)" <lihuisong@huawei.com>]

Hi chengwen,

在 2024/9/10 10:26, fengchengwen 写道:
> Hi Huisong,
>
> On 2024/8/9 17:50, Huisong Li wrote:
>> Add PM QoS configuration to declease the delay after sleep in case of
>> entering deeper idle state.
>>
>> Signed-off-by: Huisong Li <lihuisong@huawei.com>
>> Acked-by: Morten Brørup <mb@smartsharesystems.com>
>> ---
>>   examples/l3fwd-power/main.c | 24 ++++++++++++++++++++++++
>>   1 file changed, 24 insertions(+)
>>
>> diff --git a/examples/l3fwd-power/main.c b/examples/l3fwd-power/main.c
>> index 2bb6b092c3..9b386c3710 100644
>> --- a/examples/l3fwd-power/main.c
>> +++ b/examples/l3fwd-power/main.c
>> @@ -47,6 +47,7 @@
>>   #include <rte_telemetry.h>
>>   #include <rte_power_pmd_mgmt.h>
>>   #include <rte_power_uncore.h>
>> +#include <rte_power_qos.h>
>>   
>>   #include "perf_core.h"
>>   #include "main.h"
>> @@ -2260,6 +2261,22 @@ init_power_library(void)
>>   			return -1;
>>   		}
>>   	}
>> +
>> +	RTE_LCORE_FOREACH(lcore_id) {
>> +		/*
>> +		 * Set the worker lcore's to have strict latency limit to allow
>> +		 * the CPU to enter the shallowest idle state.
>> +		 */
>> +		ret = rte_power_qos_set_cpu_resume_latency(lcore_id,
>> +					RTE_POWER_QOS_STRICT_LATENCY_VALUE);
>> +		if (ret < 0) {
>> +			RTE_LOG(ERR, L3FWD_POWER,
>> +				"Failed to set strict resume latency on CPU%u.\n",
> suggest on core%u and use if (ret != 0)
Ack
>
> and how about use warning, if current system don't support it, we just give a warning message
> but let's it continue.


Because power lib is just supported and compiled on Linux.
And Linux always enable this feature. So Linux always support it.
I don't know what it would be like to compile l3fwd-power on windows.
But this is the another issue and other power APIs, like rte_power_init, 
are used directly in l3fwd-power without any condition.
So how about contiue to use error message?
>
>
>> +				lcore_id);
>> +			return ret;
>> +		}
>> +	}
>> +
>>   	return ret;
>>   }
>>   
>> @@ -2299,6 +2316,13 @@ deinit_power_library(void)
>>   			}
>>   		}
>>   	}
>> +
>> +	RTE_LCORE_FOREACH(lcore_id) {
>> +		/* Restore the original value in kernel. */
>> +		rte_power_qos_set_cpu_resume_latency(lcore_id,
>> +				RTE_POWER_QOS_RESUME_LATENCY_NO_CONSTRAINT);
>> +	}
>> +
>>   	return ret;
>>   }
>>   
>>
> .