[dpdk-dev] [PATCH v1 3/4] examples/power: allow vms to use lcores over 63

Burakov, Anatoly anatoly.burakov at intel.com
Mon Dec 10 14:06:11 CET 2018


On 22-Nov-18 5:02 PM, David Hunt wrote:
> Extending the functionality to allow vms to power manage cores beyond 63.
> 
> Signed-off-by: David Hunt <david.hunt at intel.com>
> ---
>   examples/vm_power_manager/channel_manager.c | 59 ++++++++-------------
>   examples/vm_power_manager/channel_manager.h | 30 ++---------
>   examples/vm_power_manager/channel_monitor.c | 56 +++++++------------
>   examples/vm_power_manager/vm_power_cli.c    |  4 +-
>   4 files changed, 48 insertions(+), 101 deletions(-)
> 
> diff --git a/examples/vm_power_manager/channel_manager.c b/examples/vm_power_manager/channel_manager.c
> index 5af4996db..3d493c179 100644
> --- a/examples/vm_power_manager/channel_manager.c
> +++ b/examples/vm_power_manager/channel_manager.c
> @@ -49,7 +49,7 @@ static bool global_hypervisor_available;
>    */
>   struct virtual_machine_info {
>   	char name[CHANNEL_MGR_MAX_NAME_LEN];
> -	rte_atomic64_t pcpu_mask[CHANNEL_CMDS_MAX_CPUS];
> +	uint16_t pcpu_map[CHANNEL_CMDS_MAX_CPUS];
>   	struct channel_info *channels[CHANNEL_CMDS_MAX_VM_CHANNELS];
>   	char channel_mask[POWER_MGR_MAX_CPUS];
>   	uint8_t num_channels;
> @@ -79,7 +79,7 @@ update_pcpus_mask(struct virtual_machine_info *vm_info)
>   	virVcpuInfoPtr cpuinfo;
>   	unsigned i, j;
>   	int n_vcpus;
> -	uint64_t mask;
> +	uint16_t pcpu;
>   
>   	memset(global_cpumaps, 0, CHANNEL_CMDS_MAX_CPUS*global_maplen);
>   
> @@ -120,26 +120,23 @@ update_pcpus_mask(struct virtual_machine_info *vm_info)
>   		vm_info->info.nrVirtCpu = n_vcpus;
>   	}
>   	for (i = 0; i < vm_info->info.nrVirtCpu; i++) {
> -		mask = 0;
> +		pcpu = 0;
>   		for (j = 0; j < global_n_host_cpus; j++) {
>   			if (VIR_CPU_USABLE(global_cpumaps, global_maplen, i, j) > 0) {
> -				mask |= 1ULL << j;
> +				pcpu = j;

Not sure what this does.

Initial code goes through all CPU's, marks all that are usable into mask 
(i.e. code implies there can be several), and then sets up this mask.

Now, you're going through all CPU's, store *one* arbitrary CPU index, 
and set the map up with that single index.

That doesn't look like an equivalent replacement.

>   			}
>   		}
> -		rte_atomic64_set(&vm_info->pcpu_mask[i], mask);
> +		vm_info->pcpu_map[i] = pcpu;
>   	}
>   	return 0;
>   }
>   
>   int
> -set_pcpus_mask(char *vm_name, unsigned int vcpu, char *core_mask)
> +set_pcpu(char *vm_name, unsigned int vcpu, unsigned int pcpu)

See patch 1 comments - it would've made this change easier to parse if 
set_pcpu was removed there, instead of here.

>   {
>   	unsigned i = 0;
>   	int flags = VIR_DOMAIN_AFFECT_LIVE|VIR_DOMAIN_AFFECT_CONFIG;
>   	struct virtual_machine_info *vm_info;
> -	char mask[POWER_MGR_MAX_CPUS];
> -
> -	memcpy(mask, core_mask, POWER_MGR_MAX_CPUS);
>   
>   	if (vcpu >= CHANNEL_CMDS_MAX_CPUS) {
>   		RTE_LOG(ERR, CHANNEL_MANAGER, "vCPU(%u) exceeds max allowable(%d)\n",
> @@ -166,17 +163,16 @@ set_pcpus_mask(char *vm_name, unsigned int vcpu, char *core_mask)
>   		return -1;
>   	}
>   	memset(global_cpumaps, 0 , CHANNEL_CMDS_MAX_CPUS * global_maplen);
> -	for (i = 0; i < POWER_MGR_MAX_CPUS; i++) {
> -		if (mask[i] == 1) {
> -			VIR_USE_CPU(global_cpumaps, i);
> -			if (i >= global_n_host_cpus) {
> -				RTE_LOG(ERR, CHANNEL_MANAGER, "CPU(%u) exceeds the available "
> -						"number of CPUs(%u)\n",
> -						i, global_n_host_cpus);
> -				return -1;
> -			}
> -		}
> +
> +	VIR_USE_CPU(global_cpumaps, i);
> +
> +	if (pcpu >= global_n_host_cpus) {
> +		RTE_LOG(ERR, CHANNEL_MANAGER, "CPU(%u) exceeds the available "
> +				"number of CPUs(%u)\n",
> +				i, global_n_host_cpus);
> +		return -1;
>   	}

Some comments on what the above code does would have been nice. Why the 
check was removed?

> +

-- 
Thanks,
Anatoly


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