Hi Xin,
On 2/5/25 10:24 PM, Xin Li wrote:
> On 1/22/2025 12:20 PM, Babu Moger wrote:
>> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
>> index 8917c7261680..6fe9e610e9a0 100644
>> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
>> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
>> @@ -1324,3 +1324,49 @@ int resctrl_arch_mbm_cntr_assign_set(struct rdt_resource *r, bool enable)
>> return 0;
>> }
>> +
>> +u32 resctrl_arch_mon_event_config_get(struct rdt_mon_domain *d,
>> + enum resctrl_event_id eventid)
>> +{
>> + struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d);
>> +
>> + switch (eventid) {
>> + case QOS_L3_OCCUP_EVENT_ID:
>> + break;
>> + case QOS_L3_MBM_TOTAL_EVENT_ID:
>> + return hw_dom->mbm_total_cfg;
>> + case QOS_L3_MBM_LOCAL_EVENT_ID:
>> + return hw_dom->mbm_local_cfg;
>> + }
>> +
>> + /* Never expect to get here */
>> + WARN_ON_ONCE(1);
>> +
>> + return INVALID_CONFIG_VALUE;
>> +}
>> +
>> +void resctrl_arch_mon_event_config_set(void *info)
>> +{
>> + struct mon_config_info *mon_info = info;
>> + struct rdt_hw_mon_domain *hw_dom;
>> + unsigned int index;
>> +
>> + index = mon_event_config_index_get(mon_info->evtid);
>> + if (index == INVALID_CONFIG_INDEX)
>> + return;
>> +
>> + wrmsr(MSR_IA32_EVT_CFG_BASE + index, mon_info->mon_config, 0);
>
> This is the existing code, however it would be better to use wrmsrl()
> when the higher 32-bit are all 0s:
>
> wrmsrl(MSR_IA32_EVT_CFG_BASE + index, mon_info->mon_config);
>
Could you please elaborate what makes this change better?
Thank you!
Reinette
