[AMD Official Use Only - General] Hi Reinette, > -----Original Message----- > From: Reinette Chatre <reinette.chatre@xxxxxxxxx> > Sent: Tuesday, November 22, 2022 5:43 PM > To: Moger, Babu <Babu.Moger@xxxxxxx>; Peter Newman > <peternewman@xxxxxxxxxx> > Cc: akpm@xxxxxxxxxxxxxxxxxxxx; bagasdotme@xxxxxxxxx; bp@xxxxxxxxx; > chang.seok.bae@xxxxxxxxx; corbet@xxxxxxx; > damien.lemoal@xxxxxxxxxxxxxxxxxx; daniel.sneddon@xxxxxxxxxxxxxxx; > dave.hansen@xxxxxxxxxxxxxxx; eranian@xxxxxxxxxx; fenghua.yu@xxxxxxxxx; > hpa@xxxxxxxxx; james.morse@xxxxxxx; jmattson@xxxxxxxxxx; > jpoimboe@xxxxxxxxxx; linux-doc@xxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; mingo@xxxxxxxxxx; paulmck@xxxxxxxxxx; > pawan.kumar.gupta@xxxxxxxxxxxxxxx; pbonzini@xxxxxxxxxx; > peterz@xxxxxxxxxxxxx; quic_neeraju@xxxxxxxxxxx; rdunlap@xxxxxxxxxxxxx; > Das1, Sandipan <Sandipan.Das@xxxxxxx>; songmuchun@xxxxxxxxxxxxx; > tglx@xxxxxxxxxxxxx; tony.luck@xxxxxxxxx; x86@xxxxxxxxxx > Subject: Re: [PATCH v8 10/13] x86/resctrl: Add sysfs interface to write > mbm_total_bytes_config > > Hi Babu, > > On 11/7/2022 11:00 AM, Moger, Babu wrote: > > > > On 11/7/22 04:21, Peter Newman wrote: > >> Hi Babu, > >> > >> On Fri, Nov 04, 2022 at 03:01:09PM -0500, Babu Moger wrote: > >>> + /* > >>> + * When an Event Configuration is changed, the bandwidth counters > >>> + * for all RMIDs and Events will be cleared by the hardware. The > >>> + * hardware also sets MSR_IA32_QM_CTR.Unavailable (bit 62) for > >>> + * every RMID on the next read to any event for every RMID. > >>> + * Subsequent reads will have MSR_IA32_QM_CTR.Unavailable (bit 62) > >>> + * cleared while it is tracked by the hardware. Clear the > >>> + * mbm_local and mbm_total counts for all the RMIDs. > >>> + */ > >>> + memset(d->mbm_local, 0, sizeof(struct mbm_state) * r->num_rmid); > >>> + memset(d->mbm_total, 0, sizeof(struct mbm_state) * r->num_rmid); > >> Looking around, I can't find a reader for mbm_total anymore. It looks > >> like the last place it was used went away in James's recent change: > >> > >> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flor > >> e.kernel.org%2Fall%2F20220902154829.30399-19- > james.morse%40arm.com&am > >> > p;data=05%7C01%7Cbabu.moger%40amd.com%7Ccb4a2daf65b84b45aeac08da > cce35 > >> > 66d%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C63804757402544 > 6241%7 > >> > CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI > 6Ik > >> > 1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=QZUVrpdr0YQFSJ > BbS0BHSu > >> q%2BhMwZHAA06MUqx98hD0U%3D&reserved=0 > >> > >> Are we supposed to be clearing arch_mbm_total now? > >> > > Patch got garbled in previous response. > > > > Here is it now. > > > > diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c > > b/arch/x86/kernel/cpu/resctrl/rdtgroup.c > > index 6b222f8e58ae..28d9d99a639e 100644 > > --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c > > +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c > > @@ -1517,7 +1517,7 @@ static int mbm_config_write(struct rdt_resource > > *r, struct rdt_domain *d, > > u32 evtid, u32 val) > > { > > struct mon_config_info mon_info = {0}; > > - int ret = 0; > > + int ret = 0, i; > > > > rdt_last_cmd_clear(); > > > > @@ -1557,8 +1557,10 @@ static int mbm_config_write(struct rdt_resource > > *r, struct rdt_domain *d, > > * cleared while it is tracked by the hardware. Clear the > > * mbm_local and mbm_total counts for all the RMIDs. > > */ > > - memset(d->mbm_local, 0, sizeof(struct mbm_state) * > > r->num_rmid); > > - memset(d->mbm_total, 0, sizeof(struct mbm_state) * > > r->num_rmid); > > + for (i = 0; i < r->num_rmid; i++) { > > + resctrl_arch_reset_rmid(r, d, i, > > +QOS_L3_MBM_TOTAL_EVENT_ID); > > + resctrl_arch_reset_rmid(r, d, i, > > +QOS_L3_MBM_LOCAL_EVENT_ID); > > + } > > > > write_exit: > > return ret; > > Resetting each member of an array individually seems unnecessary when the > array could just be reset as a unit. How about instead a new > resctrl_arch_reset_rmid_all() that can do so? Yes. We can do something like this below. diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index a188dacab6c8..2e67de911222 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -176,6 +176,14 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d, memset(am, 0, sizeof(*am)); } +void resctrl_arch_reset_rmid_all(struct rdt_domain *d) +{ + struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d); + + memset(hw_dom->arch_mbm_total, 0, sizeof(*hw_dom->arch_mbm_total)); + memset(hw_dom->arch_mbm_local, 0, sizeof(*hw_dom->arch_mbm_local)); +} + static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width) { u64 shift = 64 - width, chunks;
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