Re: [PATCH v8 08/13] x86/resctrl: Add sysfs interface to read mbm_total_bytes_config
From: Moger, Babu
Date: Wed Nov 23 2022 - 13:35:58 EST
Hi Reinette,
On 11/22/22 18:19, Reinette Chatre wrote:
> Hi Babu,
>
> On 11/4/2022 1:00 PM, Babu Moger wrote:
>> The current event configuration can be viewed by the user by reading
>> the configuration file /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config.
>> The event configuration settings are domain specific and will affect all
>> the CPUs in the domain.
>>
>> Following are the types of events supported:
>> ==== ===========================================================
>> Bits Description
>> ==== ===========================================================
>> 6 Dirty Victims from the QOS domain to all types of memory
>> 5 Reads to slow memory in the non-local NUMA domain
>> 4 Reads to slow memory in the local NUMA domain
>> 3 Non-temporal writes to non-local NUMA domain
>> 2 Non-temporal writes to local NUMA domain
>> 1 Reads to memory in the non-local NUMA domain
>> 0 Reads to memory in the local NUMA domain
>> ==== ===========================================================
>>
>> By default, the mbm_total_bytes_config is set to 0x7f to count all the
>> event types.
>>
>> For example:
>> $cat /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config
>> 0=0x7f;1=0x7f;2=0x7f;3=0x7f
>>
>> In this case, the event mbm_total_bytes is currently configured
>> with 0x7f on domains 0 to 3.
>>
>> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
>> ---
>> arch/x86/kernel/cpu/resctrl/internal.h | 28 ++++++++++
>> arch/x86/kernel/cpu/resctrl/monitor.c | 1
>> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 87 ++++++++++++++++++++++++++++++++
>> 3 files changed, 116 insertions(+)
>>
>> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
>> index 5459b5022760..c74285fd0f6e 100644
>> --- a/arch/x86/kernel/cpu/resctrl/internal.h
>> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
>> @@ -15,6 +15,7 @@
>> #define MSR_IA32_MBA_THRTL_BASE 0xd50
>> #define MSR_IA32_MBA_BW_BASE 0xc0000200
>> #define MSR_IA32_SMBA_BW_BASE 0xc0000280
>> +#define MSR_IA32_EVT_CFG_BASE 0xc0000400
>>
>> #define MSR_IA32_QM_CTR 0x0c8e
>> #define MSR_IA32_QM_EVTSEL 0x0c8d
>> @@ -41,6 +42,32 @@
>> */
>> #define MBM_CNTR_WIDTH_OFFSET_MAX (62 - MBM_CNTR_WIDTH_BASE)
>>
>> +/* Reads to Local DRAM Memory */
>> +#define READS_TO_LOCAL_MEM BIT(0)
>> +
>> +/* Reads to Remote DRAM Memory */
>> +#define READS_TO_REMOTE_MEM BIT(1)
>> +
>> +/* Non-Temporal Writes to Local Memory */
>> +#define NON_TEMP_WRITE_TO_LOCAL_MEM BIT(2)
>> +
>> +/* Non-Temporal Writes to Remote Memory */
>> +#define NON_TEMP_WRITE_TO_REMOTE_MEM BIT(3)
>> +
>> +/* Reads to Local Memory the system identifies as "Slow Memory" */
>> +#define READS_TO_LOCAL_S_MEM BIT(4)
>> +
>> +/* Reads to Remote Memory the system identifies as "Slow Memory" */
>> +#define READS_TO_REMOTE_S_MEM BIT(5)
>> +
>> +/* Dirty Victims to All Types of Memory */
>> +#define DIRTY_VICTIMS_TO_ALL_MEM BIT(6)
>> +
>> +/* Max event bits supported */
>> +#define MAX_EVT_CONFIG_BITS GENMASK(6, 0)
>> +
>> +/* Max configurable events */
>> +#define MAX_CONFIG_EVENTS 2
>>
> This max being disconnected from what it is a max of looks like
> a source of future confusion.
ok, Not required anymore with your suggested change below. Will remove it.
>
>> struct rdt_fs_context {
>> struct kernfs_fs_context kfc;
>> @@ -542,5 +569,6 @@ bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d);
>> void __check_limbo(struct rdt_domain *d, bool force_free);
>> void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
>> void __init thread_throttle_mode_init(void);
>> +void mbm_config_rftype_init(void);
>>
>> #endif /* _ASM_X86_RESCTRL_INTERNAL_H */
>> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
>> index 06c2dc980855..a188dacab6c8 100644
>> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
>> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
>> @@ -787,6 +787,7 @@ int rdt_get_mon_l3_config(struct rdt_resource *r)
>> if (mon_configurable) {
>> mbm_total_event.configurable = true;
>> mbm_local_event.configurable = true;
>> + mbm_config_rftype_init();
>> }
>>
>> l3_mon_evt_init(r);
>> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> index 8342feb54a7f..dea58b6b4aa4 100644
>> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> @@ -1423,6 +1423,78 @@ static int rdtgroup_size_show(struct kernfs_open_file *of,
>> return ret;
>> }
>>
>> +struct mon_config_info {
>> + u32 evtid;
>> + u32 mon_config;
>> +};
>> +
>> +/**
>> + * mon_event_config_index_get - get the index for the configurable event
>> + * @evtid: event id.
>> + *
>> + * Return: 0 for evtid == QOS_L3_MBM_TOTAL_EVENT_ID
>> + * 1 for evtid == QOS_L3_MBM_LOCAL_EVENT_ID
>> + * > 1 otherwise
>> + */
>> +static inline unsigned int mon_event_config_index_get(u32 evtid)
>> +{
>> + return evtid - QOS_L3_MBM_TOTAL_EVENT_ID;
>> +}
> It seems strange that the validation of the index is split
> from where the index is determined. I think it would be easier
> to understand, and reduce code duplication, it if is done together.
>
> How about:
> #define INVALID_CONFIG_INDEX UINT_MAX
>
> static inline unsigned int mon_event_config_index_get(u32 evtid)
> {
> switch (evtid) {
> case QOS_L3_MBM_TOTAL_EVENT_ID:
> return 0;
> case QOS_L3_MBM_LOCAL_EVENT_ID:
> return 1;
> default:
> /* WARN */
> return INVALID_CONFIG_INDEX;
> }
> }
>
> What do you think?
Yes. It should work
>
>> +
>> +static void mon_event_config_read(void *info)
>> +{
>> + struct mon_config_info *mon_info = info;
>> + u32 h, index;
>> +
>> + index = mon_event_config_index_get(mon_info->evtid);
>> + if (index >= MAX_CONFIG_EVENTS) {
>> + pr_warn_once("Invalid event id %d\n", mon_info->evtid);
>> + return;
>> + }
>> + rdmsr(MSR_IA32_EVT_CFG_BASE + index, mon_info->mon_config, h);
>> +}
>> +
>> +static void mondata_config_read(struct rdt_domain *d, struct mon_config_info *mon_info)
>> +{
>> + smp_call_function_any(&d->cpu_mask, mon_event_config_read, mon_info, 1);
>> +}
>> +
>> +static int mbm_config_show(struct seq_file *s, struct rdt_resource *r, u32 evtid)
>> +{
>> + struct mon_config_info mon_info = {0};
>> + struct rdt_domain *dom;
>> + bool sep = false;
>> +
>> + mutex_lock(&rdtgroup_mutex);
>> +
>> + list_for_each_entry(dom, &r->domains, list) {
>> + if (sep)
>> + seq_puts(s, ";");
>> +
>> + mon_info.evtid = evtid;
>> + mondata_config_read(dom, &mon_info);
>> +
>> + seq_printf(s, "%d=0x%02lx", dom->id,
> This is a u32 ... is just x sufficient?
I have added 0x%02lx to silence the compiler. Not required anymore.
>
>> + mon_info.mon_config & MAX_EVT_CONFIG_BITS);
> Please do this masking within mondata_config_read(). It should
> not be required for every mon_config_read() caller to validate the
> data because they may forget (re. patch 10).
Sure. Will do.
>
>> + sep = true;
>> + }
>> + seq_puts(s, "\n");
>> +
>> + mutex_unlock(&rdtgroup_mutex);
>> +
>> + return 0;
>> +}
>> +
>> +static int mbm_total_bytes_config_show(struct kernfs_open_file *of,
>> + struct seq_file *seq, void *v)
>> +{
>> + struct rdt_resource *r = of->kn->parent->priv;
>> +
>> + mbm_config_show(seq, r, QOS_L3_MBM_TOTAL_EVENT_ID);
>> +
>> + return 0;
>> +}
>> +
>> /* rdtgroup information files for one cache resource. */
>> static struct rftype res_common_files[] = {
>> {
>> @@ -1521,6 +1593,12 @@ static struct rftype res_common_files[] = {
>> .seq_show = max_threshold_occ_show,
>> .fflags = RF_MON_INFO | RFTYPE_RES_CACHE,
>> },
>> + {
>> + .name = "mbm_total_bytes_config",
>> + .mode = 0444,
>> + .kf_ops = &rdtgroup_kf_single_ops,
>> + .seq_show = mbm_total_bytes_config_show,
>> + },
>> {
>> .name = "cpus",
>> .mode = 0644,
>> @@ -1627,6 +1705,15 @@ void __init thread_throttle_mode_init(void)
>> rft->fflags = RF_CTRL_INFO | RFTYPE_RES_MB;
>> }
>>
>> +void mbm_config_rftype_init(void)
> Does this need __init?
Not. Required. Will remove it.
Thanks
Babu
>
>> +{
>> + struct rftype *rft;
>> +
>> + rft = rdtgroup_get_rftype_by_name("mbm_total_bytes_config");
>> + if (rft)
>> + rft->fflags = RF_MON_INFO | RFTYPE_RES_CACHE;
>> +}
>> +
>> /**
>> * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file
>> * @r: The resource group with which the file is associated.
>>
>>
> Reinette
--
Thanks
Babu Moger