From: James Morse <james.morse@arm.com>
To: Reinette Chatre <reinette.chatre@intel.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
H Peter Anvin <hpa@zytor.com>, Babu Moger <Babu.Moger@amd.com>,
shameerali.kolothum.thodi@huawei.com,
Jamie Iles <jamie@nuviainc.com>,
D Scott Phillips OS <scott@os.amperecomputing.com>,
lcherian@marvell.com, bobo.shaobowang@huawei.com,
tan.shaopeng@fujitsu.com
Subject: Re: [PATCH v2 08/23] x86/resctrl: Create mba_sc configuration in the rdt_domain
Date: Fri, 22 Oct 2021 19:30:18 +0100 [thread overview]
Message-ID: <96e481ad-f544-dd7d-294d-461f905bcb1e@arm.com> (raw)
In-Reply-To: <facea348-2c54-fe52-09b9-8feccd15db2d@intel.com>
Hi Reinette,
On 15/10/2021 23:26, Reinette Chatre wrote:
> On 10/1/2021 9:02 AM, James Morse wrote:
>> To support resctrl's MBA software controller, the architecture must provide
>> a second configuration array to hold the mbps_val from user-space.
>>
>> This complicates the interface between the architecture code.
>
> This complicates the interface between the architecture code and ... ?
and the filesystem parts ... fixed.
>> Make the filesystem parts of resctrl create an array for the mba_sc
>> values when is_mba_sc() is set to true. The software controller
>> can be changed to use this, allowing the architecture code to only
>> consider the values configured in hardware.
> This changes significantly more than just where the mbps_val array is hosted. It also
> changes how the life cycle of this array is managed. Previously it followed the domain,
> whether mba_sc was enabled or not. Now that it depends on mba_sc it is managed quite
> differently.
> Could the changelog be upfront about this change and its motivation? Stating this would
> make this much easier to review and also the later patches where the original mbps_val
> initialization code is removed without replacement.
Yes, I'd not considered those as different things. I'll split this into two patches, and
move the change that only allocates the memory if its going to be used to the end of the
series.
>> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> index 38670bb810cb..9d402bc8bdff 100644
>> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> @@ -3291,6 +3355,9 @@ static int domain_setup_mon_state(struct rdt_resource *r, struct
>> rdt_domain *d)
>> }
>> }
>> + if (is_mba_sc(r))
>> + return mba_sc_domain_allocate(r, d);
>> +
>> return 0;
>> }
>>
> Could this be done symmetrically? That is, allocate in resctrl_online_domain() and free in
> resctrl_offline_domain().
Yes, that would be better!
>> diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
>> index 5d283bdd6162..355660d46612 100644
>> --- a/include/linux/resctrl.h
>> +++ b/include/linux/resctrl.h
>> @@ -15,6 +15,9 @@ int proc_resctrl_show(struct seq_file *m,
>> #endif
>> +/* max value for struct resctrl_mba_sc's mbps_val */
>> +#define MBA_MAX_MBPS U32_MAX
>
> struct resctrl_mba_sc?
Was squashed out of the previous version as it only had one member.
This should be struct rdt_domain.
>> /**
>> * enum resctrl_conf_type - The type of configuration.
>> * @CDP_NONE: No prioritisation, both code and data are controlled or monitored.
>> @@ -53,6 +56,8 @@ struct resctrl_staged_config {
>> * @cqm_work_cpu: worker CPU for CQM h/w counters
>> * @plr: pseudo-locked region (if any) associated with domain
>> * @staged_config: parsed configuration to be applied
>> + * @mbps_val: Array of user specified control values for mba_sc,
>> + * indexed by closid
> Could this inherit some of the useful kerneldoc associated with the mbps_val being
> replaced? That is, it exists when mba_sc is enabled and contains bandwidth values in MBps.
Yup, done.
Thanks,
James
next prev parent reply other threads:[~2021-10-22 18:30 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-01 16:02 [PATCH v2 00/23] x86/resctrl: Make resctrl_arch_rmid_read() return values in bytes James Morse
2021-10-01 16:02 ` [PATCH v2 01/23] x86/resctrl: Free the ctrlval arrays when domain_setup_mon_state() fails James Morse
2021-10-01 16:02 ` [PATCH v2 02/23] x86/resctrl: Fix kfree() of the wrong type in domain_add_cpu() James Morse
2021-10-01 16:02 ` [PATCH v2 03/23] x86/resctrl: Kill off alloc_enabled James Morse
2021-10-15 22:19 ` Reinette Chatre
2021-10-01 16:02 ` [PATCH v2 04/23] x86/resctrl: Merge mon_capable and mon_enabled James Morse
2021-10-19 23:18 ` Babu Moger
2021-10-22 18:30 ` James Morse
2021-10-01 16:02 ` [PATCH v2 05/23] x86/resctrl: Add domain online callback for resctrl work James Morse
2021-10-15 22:19 ` Reinette Chatre
2021-10-22 18:30 ` James Morse
2021-10-19 23:19 ` Babu Moger
2021-10-22 18:30 ` James Morse
2021-10-01 16:02 ` [PATCH v2 06/23] x86/resctrl: Group struct rdt_hw_domain cleanup James Morse
2021-10-01 16:02 ` [PATCH v2 07/23] x86/resctrl: Add domain offline callback for resctrl work James Morse
2021-10-19 23:19 ` Babu Moger
2021-10-22 18:30 ` James Morse
2021-10-01 16:02 ` [PATCH v2 08/23] x86/resctrl: Create mba_sc configuration in the rdt_domain James Morse
2021-10-15 22:26 ` Reinette Chatre
2021-10-22 18:30 ` James Morse [this message]
2021-10-01 16:02 ` [PATCH v2 09/23] x86/resctrl: Switch over to the resctrl mbps_val list James Morse
2021-10-15 22:26 ` Reinette Chatre
2021-10-27 16:49 ` James Morse
2021-10-01 16:02 ` [PATCH v2 10/23] x86/resctrl: Remove architecture copy of mbps_val James Morse
2021-10-15 22:27 ` Reinette Chatre
2021-10-27 16:49 ` James Morse
2021-10-01 16:02 ` [PATCH v2 11/23] x86/resctrl: Remove set_mba_sc()s control array re-initialisation James Morse
2021-10-01 16:02 ` [PATCH v2 12/23] x86/resctrl: Abstract and use supports_mba_mbps() James Morse
2021-10-07 6:13 ` tan.shaopeng
2021-10-27 16:50 ` James Morse
2021-10-15 22:28 ` Reinette Chatre
2021-10-01 16:02 ` [PATCH v2 13/23] x86/resctrl: Allow update_mba_bw() to update controls directly James Morse
2021-10-15 22:28 ` Reinette Chatre
2021-10-27 16:49 ` James Morse
2021-10-01 16:02 ` [PATCH v2 14/23] x86/resctrl: Calculate bandwidth from the previous __mon_event_count() chunks James Morse
2021-10-15 22:28 ` Reinette Chatre
2021-10-27 16:50 ` James Morse
2021-10-27 20:41 ` Reinette Chatre
2021-10-29 15:50 ` James Morse
2021-10-29 22:22 ` Reinette Chatre
2021-10-01 16:02 ` [PATCH v2 15/23] x86/recstrl: Add per-rmid arch private storage for overflow and chunks James Morse
2021-10-15 22:29 ` Reinette Chatre
2021-10-01 16:02 ` [PATCH v2 16/23] x86/recstrl: Allow per-rmid arch private storage to be reset James Morse
2021-10-07 6:16 ` tan.shaopeng
2021-10-01 16:02 ` [PATCH v2 17/23] x86/resctrl: Abstract __rmid_read() James Morse
2021-10-15 22:29 ` Reinette Chatre
2021-10-19 23:20 ` Babu Moger
2021-10-20 18:15 ` Reinette Chatre
2021-10-20 19:22 ` Babu Moger
2021-10-20 20:28 ` Reinette Chatre
2021-10-27 16:50 ` James Morse
2021-10-27 18:59 ` Babu Moger
2021-10-01 16:02 ` [PATCH v2 18/23] x86/resctrl: Pass the required parameters into resctrl_arch_rmid_read() James Morse
2021-10-15 22:30 ` Reinette Chatre
2021-10-01 16:02 ` [PATCH v2 19/23] x86/resctrl: Move mbm_overflow_count() " James Morse
2021-10-01 16:02 ` [PATCH v2 20/23] x86/resctrl: Move get_corrected_mbm_count() " James Morse
2021-10-01 16:03 ` [PATCH v2 21/23] x86/resctrl: Rename and change the units of resctrl_cqm_threshold James Morse
2021-10-01 16:03 ` [PATCH v2 22/23] x86/resctrl: Add resctrl_rmid_realloc_limit to abstract x86's boot_cpu_data James Morse
2021-10-01 16:03 ` [PATCH v2 23/23] x86/resctrl: Make resctrl_arch_rmid_read() return values in bytes James Morse
2021-10-13 2:09 ` [PATCH v2 00/23] " tan.shaopeng
2021-10-19 23:17 ` Babu Moger
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