Hi James,
On 8/16/24 11:32, James Morse wrote:
> Hi Babu,
>
> On 06/08/2024 23:00, Babu Moger wrote:
>> Enable ABMC by default when supported during the boot up.
>>
>> Users will not see any difference in the behavior when resctrl is
>> mounted. With automatic assignment everything will work as running
>> in the legacy monitor mode.
>
>> diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
>> index 6fb0cfdb5529..a7980f84c487 100644
>> --- a/arch/x86/kernel/cpu/resctrl/core.c
>> +++ b/arch/x86/kernel/cpu/resctrl/core.c
>> @@ -599,6 +599,7 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
>> d = container_of(hdr, struct rdt_mon_domain, hdr);
>>
>> cpumask_set_cpu(cpu, &d->hdr.cpu_mask);
>> + resctrl_arch_mbm_cntr_assign_configure();
>> return;
>> }
>>
>> @@ -620,6 +621,7 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
>> arch_mon_domain_online(r, d);
>>
>> resctrl_mbm_evt_config_init(hw_dom);
>> + resctrl_arch_mbm_cntr_assign_configure();
>>
>> if (arch_domain_mbm_alloc(r->mon.num_rmid, hw_dom)) {
>> mon_domain_free(hw_dom);
>
>> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> index 66febff2a3d3..d15fd1bde5f4 100644
>> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> @@ -2756,6 +2756,23 @@ void resctrl_arch_mbm_cntr_assign_disable(void)
>> }
>> }
>>
>> +void resctrl_arch_mbm_cntr_assign_configure(void)
>> +{
>> + struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
>> + struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
>> + bool enable = true;
>> +
>> + mutex_lock(&rdtgroup_mutex);
>
> As before - this lock isn't available to the architecture code after the filesystem code
> moves to /fs/. To prevent concurrent calls to resctrl_abmc_set_one_amd() I think you need
> your own mutex.
These calls are originated from domain_add_cpu_mon sequence. It holds the
lock already. We should be good. I will remove the lock.
>
>
>> + if (r->mon.mbm_cntr_assignable) {
>> + if (!hw_res->mbm_cntr_assign_enabled)
>> + hw_res->mbm_cntr_assign_enabled = true;
>> + resctrl_abmc_set_one_amd(&enable);
>> + }
>> +
>> + mutex_unlock(&rdtgroup_mutex);
>> +}
>
> Neither of this functions callers are in filesystem code, could you drop the 'arch' from
> the name - it isn't part of the fs/arch interface.
Yes. Sure.
>
>
> Thanks,
>
> James
>
--
Thanks
Babu Moger
