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Message-ID: <b10fbeb9-6ab8-4cc1-a786-9a62faa27946@amd.com>
Date: Tue, 16 Jul 2024 14:21:20 -0500
From: "Moger, Babu" <babu.moger@....com>
To: Reinette Chatre <reinette.chatre@...el.com>, corbet@....net,
fenghua.yu@...el.com, tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
dave.hansen@...ux.intel.com
Cc: x86@...nel.org, hpa@...or.com, paulmck@...nel.org, rdunlap@...radead.org,
tj@...nel.org, peterz@...radead.org, yanjiewtw@...il.com,
kim.phillips@....com, lukas.bulwahn@...il.com, seanjc@...gle.com,
jmattson@...gle.com, leitao@...ian.org, jpoimboe@...nel.org,
rick.p.edgecombe@...el.com, kirill.shutemov@...ux.intel.com,
jithu.joseph@...el.com, kai.huang@...el.com, kan.liang@...ux.intel.com,
daniel.sneddon@...ux.intel.com, pbonzini@...hat.com, sandipan.das@....com,
ilpo.jarvinen@...ux.intel.com, peternewman@...gle.com,
maciej.wieczor-retman@...el.com, linux-doc@...r.kernel.org,
linux-kernel@...r.kernel.org, eranian@...gle.com, james.morse@....com
Subject: Re: [PATCH v5 10/20] x86/resctrl: Introduce mbm_total_cfg and
mbm_local_cfg
Hi Reinette,
On 7/12/24 17:08, Reinette Chatre wrote:
> Hi Babu,
>
> On 7/3/24 2:48 PM, Babu Moger wrote:
>> If the BMEC (Bandwidth Monitoring Event Configuration) feature is
>> supported, the bandwidth events can be configured to track specific
>> events. The event configuration is domain specific. ABMC (Assignable
>> Bandwidth Monitoring Counters) feature needs event configuration
>> information to assign hardware counter to an RMID. Event configurations
>> are not stored in resctrl but instead always read from or written to
>> hardware directly when prompted by user space.
>>
>> Read the event configuration from the hardware during the domain
>> initialization. Save the configuration information in the rdt_hw_domain,
>
> rdt_hw_domain -> rdt_hw_mon_domain
Sure.
>
>> so it can be used for counter assignment.
>>
>> Signed-off-by: Babu Moger <babu.moger@....com>
>> ---
>> v5: Exported mon_event_config_index_get.
>> Renamed arch_domain_mbm_evt_config to resctrl_arch_mbm_evt_config.
>>
>> v4: Read the configuration information from the hardware to initialize.
>> Added few commit messages.
>> Fixed the tab spaces.
>>
>> v3: Minor changes related to rebase in mbm_config_write_domain.
>>
>> v2: No changes.
>> ---
>> arch/x86/kernel/cpu/resctrl/core.c | 2 ++
>> arch/x86/kernel/cpu/resctrl/internal.h | 6 ++++++
>> arch/x86/kernel/cpu/resctrl/monitor.c | 22 ++++++++++++++++++++++
>> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 2 +-
>> 4 files changed, 31 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/kernel/cpu/resctrl/core.c
>> b/arch/x86/kernel/cpu/resctrl/core.c
>> index ff5cb693b396..6265ef8b610f 100644
>> --- a/arch/x86/kernel/cpu/resctrl/core.c
>> +++ b/arch/x86/kernel/cpu/resctrl/core.c
>> @@ -619,6 +619,8 @@ static void domain_add_cpu_mon(int cpu, struct
>> rdt_resource *r)
>> arch_mon_domain_online(r, d);
>> + resctrl_arch_mbm_evt_config(hw_dom);
>> +
>
> This does not look to be an arch call called by the fs code so special
> naming does not seem to be required? If it _was_ an arch callback then
Yes. Correct.
> it cannot take a HW resource as parameter since the fs code does not have
> access to that.
>
>
>> if (arch_domain_mbm_alloc(r->mon.num_rmid, hw_dom)) {
>> mon_domain_free(hw_dom);
>> return;
>> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h
>> b/arch/x86/kernel/cpu/resctrl/internal.h
>> index 0ce9797f80fe..4cb1a5d014a3 100644
>> --- a/arch/x86/kernel/cpu/resctrl/internal.h
>> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
>> @@ -401,6 +401,8 @@ struct rdt_hw_ctrl_domain {
>> * @d_resctrl: Properties exposed to the resctrl file system
>> * @arch_mbm_total: arch private state for MBM total bandwidth
>> * @arch_mbm_local: arch private state for MBM local bandwidth
>> + * @mbm_total_cfg: MBM total bandwidth configuration
>> + * @mbm_local_cfg: MBM local bandwidth configuration
>> *
>> * Members of this structure are accessed via helpers that provide
>> abstraction.
>> */
>> @@ -408,6 +410,8 @@ struct rdt_hw_mon_domain {
>> struct rdt_mon_domain d_resctrl;
>> struct arch_mbm_state *arch_mbm_total;
>> struct arch_mbm_state *arch_mbm_local;
>> + u32 mbm_total_cfg;
>> + u32 mbm_local_cfg;
>> };
>> static inline struct rdt_hw_ctrl_domain
>> *resctrl_to_arch_ctrl_dom(struct rdt_ctrl_domain *r)
>> @@ -662,6 +666,8 @@ void __check_limbo(struct rdt_mon_domain *d, bool
>> force_free);
>> void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
>> void __init resctrl_file_fflags_init(const char *config,
>> unsigned long fflags);
>> +void resctrl_arch_mbm_evt_config(struct rdt_hw_mon_domain *hw_dom);
>> +unsigned int mon_event_config_index_get(u32 evtid);
>> void rdt_staged_configs_clear(void);
>> bool closid_allocated(unsigned int closid);
>> int resctrl_find_cleanest_closid(void);
>> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c
>> b/arch/x86/kernel/cpu/resctrl/monitor.c
>> index 7a93a6d2b2de..b96b0a8bd7d3 100644
>> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
>> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
>> @@ -1256,6 +1256,28 @@ int __init rdt_get_mon_l3_config(struct
>> rdt_resource *r)
>> return 0;
>> }
>> +void resctrl_arch_mbm_evt_config(struct rdt_hw_mon_domain *hw_dom)
>
> A function is expected to have a verb in its name and the verb here seems
> to be
> "config", which does not seem appropriate and creates confusion with
> resctrl_arch_event_config_set(). How about resctrl_arch_mbm_evt_config_init()
> with proper initializer of the config values to also cover case when
> events are
> not configurable (INVALID_CONFIG_VALUE introduced in next patch?) ?
Sorry. I am not clear on this comment. Can you please elaborate?
>
>> +{
>> + unsigned int index;
>> + u64 msrval;
>> +
>> + /*
>> + * Read the configuration registers QOS_EVT_CFG_n, where <n> is
>> + * the BMEC event number (EvtID).
>> + */
>> + if (mbm_total_event.configurable) {
>> + index = mon_event_config_index_get(QOS_L3_MBM_TOTAL_EVENT_ID);
>> + rdmsrl(MSR_IA32_EVT_CFG_BASE + index, msrval);
>> + hw_dom->mbm_total_cfg = msrval & MAX_EVT_CONFIG_BITS;
>> + }
>> +
>> + if (mbm_local_event.configurable) {
>> + index = mon_event_config_index_get(QOS_L3_MBM_LOCAL_EVENT_ID);
>> + rdmsrl(MSR_IA32_EVT_CFG_BASE + index, msrval);
>> + hw_dom->mbm_local_cfg = msrval & MAX_EVT_CONFIG_BITS;
>> + }
>> +}
>> +
>> void __exit rdt_put_mon_l3_config(void)
>> {
>> dom_data_exit();
>> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> index b3d3fa048f15..b2b751741dd8 100644
>> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> @@ -1606,7 +1606,7 @@ struct mon_config_info {
>> * 1 for evtid == QOS_L3_MBM_LOCAL_EVENT_ID
>> * INVALID_CONFIG_INDEX for invalid evtid
>> */
>> -static inline unsigned int mon_event_config_index_get(u32 evtid)
>> +unsigned int mon_event_config_index_get(u32 evtid)
>> {
>> switch (evtid) {
>> case QOS_L3_MBM_TOTAL_EVENT_ID:
>
> Reinette
>
--
Thanks
Babu Moger
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