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>>>> } >>>> + >>>> +static void resctrl_abmc_config_one_amd(void *info) >>>> +{ >>>> + union l3_qos_abmc_cfg *abmc_cfg = info; >>>> + >>>> + wrmsrl(MSR_IA32_L3_QOS_ABMC_CFG, abmc_cfg->full); >>>> +} >>>> + >>>> +/* >>>> + * Send an IPI to the domain to assign the counter to RMID, event pair. >>>> + */ >>>> +void resctrl_arch_config_cntr(struct rdt_resource *r, struct rdt_mon_domain *d, >>>> + enum resctrl_event_id evtid, u32 rmid, u32 closid, >>>> + u32 cntr_id, bool assign) >>>> +{ >>>> + struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d); >>>> + union l3_qos_abmc_cfg abmc_cfg = { 0 }; >>>> + struct arch_mbm_state *am; >>>> + >>>> + abmc_cfg.split.cfg_en = 1; >>>> + abmc_cfg.split.cntr_en = assign ? 1 : 0; >>>> + abmc_cfg.split.cntr_id = cntr_id; >>>> + abmc_cfg.split.bw_src = rmid; >>>> + if (assign) >>>> + abmc_cfg.split.bw_type = resctrl_get_mon_evt_cfg(evtid); >>>> + >>>> + smp_call_function_any(&d->hdr.cpu_mask, resctrl_abmc_config_one_amd, &abmc_cfg, 1); >>> >>> An optimization to consider is to direct the IPI to a housekeeping CPU. >>> If one exist, a further optimization could be to queue it on that CPU >>> instead of IPI. Your call since I am not familiar with the use cases here. >>> Looks like all paths leading to this is triggered by a user space action >>> (mount, mkdir, or write to update event config). This would require exposing >>> the housekeeping CPU code to arch. >> >> Do you mean something like this? >> >> cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask, RESCTRL_PICK_ANY_CPU); >> >> smp_call_on_cpu(cpu, resctrl_abmc_config_one_amd, &abmc_cfg, false); > > Please note the returned "cpu" may be nohz_full and if it is it would need > an IPI. Similar to mon_event_read(). > Yes. Got that. >> >> >> You want to do these changes now or later? It requires few other changes >> to move around the code. > > I'll leave this up to you. I think it would be ideal if cpumask_any_housekeeping() > can be hosted in include/linux/cpumask.h instead of moving it around within > resctrl. > ok. It will be couple more patches to re-arrange all the related code. I would prefer its done separately. -- Thanks Babu Moger