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Message-ID: <d6f5affa-1f7d-7944-70a3-6d2c99863fad@amd.com>
Date: Fri, 26 Aug 2022 11:49:19 -0500
From: "Moger, Babu" <babu.moger@....com>
To: Reinette Chatre <reinette.chatre@...el.com>, fenghua.yu@...el.com,
tglx@...utronix.de, mingo@...hat.com, bp@...en8.de
Cc: eranian@...gle.com, dave.hansen@...ux.intel.com, x86@...nel.org,
hpa@...or.com, corbet@....net, linux-kernel@...r.kernel.org,
linux-doc@...r.kernel.org, bagasdotme@...il.com
Subject: Re: [PATCH v3 08/10] x86/resctrl: Add the sysfs interface to read the
event configuration
On 8/24/22 16:16, Reinette Chatre wrote:
> Hi Babu,
>
> On 8/22/2022 6:44 AM, Babu Moger wrote:
>> The current event configuration can be viewed by the user by reading
>> the sysfs configuration file.
>>
>> 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 configuration is set to 0x7f to count
>> all the types of events and mbm_local_bytes configuration is set to
>> 0x15 to count all the local memory events.
>>
>> $cat /sys/fs/resctrl/mon_data/mon_L3_00/mbm_total_config
>> 0x7f
>>
>> $cat /sys/fs/resctrl/mon_data/mon_L3_00/mbm_local_config
>> 0x15
>>
>> Signed-off-by: Babu Moger <babu.moger@....com>
>> Reviewed-by: Ingo Molnar <mingo@...nel.org>
>> ---
>> arch/x86/kernel/cpu/resctrl/internal.h | 21 ++++++++++
>> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 70 ++++++++++++++++++++++++++++++++
>> 2 files changed, 91 insertions(+)
>>
>> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
>> index fc725f5e9024..457666709386 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
>> @@ -50,6 +51,26 @@
>> */
>> #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" */
> Seems unexpected character slipped into "identifies".
Sure. Will fix it
>
>> +#define READS_TO_LOCAL_S_MEM BIT(4)
>> +
>> +/* Reads to Remote Memory the system identifies as "Slow Memory" */
> here also
sure. Will fix it.
>
>> +#define READS_TO_REMOTE_S_MEM BIT(5)
>> +
>> +/* Dirty Victims to All Types of Memory */
>> +#define DIRTY_VICTIS_TO_ALL_MEM BIT(6)
> Is this intended to be "DIRTY_VICTIMS_TO_ALL_MEM" ?
Yes. that is what spec says.
>
>>
>> struct rdt_fs_context {
>> struct kernfs_fs_context kfc;
>> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> index 30d2182d4fda..e1847d49fa15 100644
>> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> @@ -254,8 +254,78 @@ static const struct kernfs_ops kf_mondata_ops = {
>> .seq_show = rdtgroup_mondata_show,
>> };
>>
>> +/*
>> + * This is called via IPI to read the CQM/MBM counters
>> + * in a domain.
>> + */
>> +void mon_event_config_read(void *info)
>> +{
>> + union mon_data_bits *md = info;
>> + u32 evtid = md->u.evtid;
>> + u32 h, msr_index;
>> +
>> + switch (evtid) {
>> + case QOS_L3_MBM_TOTAL_EVENT_ID:
>> + msr_index = 0;
>> + break;
>> + case QOS_L3_MBM_LOCAL_EVENT_ID:
>> + msr_index = 1;
>> + break;
>> + default:
>> + return; /* Not expected to come here */
> Please no inline comments.
Ok
>
>> + }
>> +
>> + rdmsr(MSR_IA32_EVT_CFG_BASE + msr_index, md->u.mon_config, h);
>> +}
>> +
>> +void mondata_config_read(struct rdt_domain *d, union mon_data_bits *md)
>> +{
>> + smp_call_function_any(&d->cpu_mask, mon_event_config_read, md, 1);
>> +}
>> +
>> +int rdtgroup_mondata_config_show(struct seq_file *m, void *arg)
>> +{
>> + struct kernfs_open_file *of = m->private;
>> + struct rdt_hw_resource *hw_res;
>> + u32 resid, evtid, domid;
>> + struct rdtgroup *rdtgrp;
>> + struct rdt_resource *r;
>> + union mon_data_bits md;
>> + struct rdt_domain *d;
>> + int ret = 0;
>> +
>> + rdtgrp = rdtgroup_kn_lock_live(of->kn);
>> + if (!rdtgrp) {
>> + ret = -ENOENT;
>> + goto out;
>> + }
>> +
>> + md.priv = of->kn->priv;
>> + resid = md.u.rid;
>> + domid = md.u.domid;
>> + evtid = md.u.evtid;
>> +
>> + hw_res = &rdt_resources_all[resid];
>> + r = &hw_res->r_resctrl;
>> +
>> + d = rdt_find_domain(r, domid, NULL);
>> + if (IS_ERR_OR_NULL(d)) {
>> + ret = -ENOENT;
>> + goto out;
>> + }
>> +
>> + mondata_config_read(d, &md);
>> +
>> + seq_printf(m, "0x%x\n", md.u.mon_config);
> Looking at this patch and the next, the sysfs files are introduced to read
> from and write to the configuration register. From what I can tell the
> data is never used internally (what did I miss?). Why is the value of the
> configuration register stored?
You didn't miss anything. We don't need to store it. But we need it as
part of mon_data_bits structure because, it need to be passed to
mon_event_config_read and rdtgroup_mondata_config_write.
In these functions we need evtid and also config value (mon_config).
Thanks
Babu
>
>> +
>> +out:
>> + rdtgroup_kn_unlock(of->kn);
>> + return ret;
>> +}
>> +
>> static const struct kernfs_ops kf_mondata_config_ops = {
>> .atomic_write_len = PAGE_SIZE,
>> + .seq_show = rdtgroup_mondata_config_show,
>> };
>>
>> static bool is_cpu_list(struct kernfs_open_file *of)
>>
>>
>
> Reinette
--
Thanks
Babu Moger
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