From: Yury Norov <ynorov@caviumnetworks.com>
To: James Morse <james.morse@arm.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Fenghua Yu <fenghua.yu@intel.com>,
Tony Luck <tony.luck@intel.com>, Ingo Molnar <mingo@redhat.com>,
H Peter Anvin <hpa@zytor.com>,
Reinette Chatre <reinette.chatre@intel.com>,
Vikas Shivappa <vikas.shivappa@linux.intel.com>,
"Norov, Yuri" <Yuri.Norov@cavium.com>
Subject: Re: [RFC PATCH 00/20] x86/intel_rdt: Start abstraction for a second arch
Date: Tue, 27 Nov 2018 12:33:30 +0000 [thread overview]
Message-ID: <20181127123319.GA24166@yury-thinkpad> (raw)
In-Reply-To: <20180824104519.11203-1-james.morse@arm.com>
Hi James,
On Fri, Aug 24, 2018 at 11:44:59AM +0100, James Morse wrote:
> Hi folks,
>
> ARM have some upcoming CPU features that are similar to Intel RDT. Resctrl
> is the defacto ABI for this sort of thing, but it lives under arch/x86.
>
> To get existing software working, we need to make resctrl work with arm64.
> This series is the first chunk of that. The aim is to move the filesystem/ABI
> parts into /fs/resctrl, and implement a second arch backend.
>
>
> What are the ARM features?
> Future ARM SoCs may have a feature called MPAM: Memory Partitioning and
> Monitoring. This is an umbrella term like RDT, and covers a range of controls
> (like CAT) and monitors (like MBM, CMT).
>
> This series is almost all about CDP. MPAM has equivalent functionality, but
> it doesn't need enabling, and doesn't affect the available closids. (I'll
> try and use Intel terms). MPAM expects the equivalent to IA32_PRQ_MSR to
> be configured with an Instruction closid and a Data closid. These are the
> same for no-CDP, and different otherwise. There is no need for them to be
> adjacent.
>
> To avoid emulating CDP in arm64's arch code, this series moves all the ABI
> parts of the CDP behaviour, (half the closid-space, each having two
> configurations) into the filesystem parts of resctrl. These will eventually
> be moved to /fs/.
>
> MPAMs control and monitor configuration is all memory mapped, the base
> addresses are discovered via firmware tables, so we won't have a table of
> possible resources that just need alloc_enabling.
>
> Is this it? No... there are another two series of a similar size that
> abstract the MBM/CMT overflow threads and avoid 'fs' code accessing things
> that have moved into the 'hw' arch specific struct.
>
>
> I'm after feedback on the general approach taken here, bugs, as there are
> certainly subtleties I've missed, and any strong-opinions on what should be
> arch-specific, and what shouldn't.
>
> This series is based on v4.18, and can be retrieved from:
> git://linux-arm.org/linux-jm.git -b mpam/resctrl_rework/rfc_1
Thank you a lot for this work on cache allocation.
We are very interested in enabling CAT on Cavium / Marvell devices.
Could you please share another two series you mentioned above?
Do you have a working ARM64 CAT driver? It will much help us in our
experimenting.
Thanks in advance,
Yury
next prev parent reply other threads:[~2018-11-27 12:33 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-24 10:44 [RFC PATCH 00/20] x86/intel_rdt: Start abstraction for a second arch James Morse
2018-08-24 10:45 ` [RFC PATCH 01/20] x86/intel_rdt: Split struct rdt_resource James Morse
2018-08-24 10:45 ` [RFC PATCH 02/20] x86/intel_rdt: Split struct rdt_domain James Morse
2018-08-24 10:45 ` [RFC PATCH 03/20] x86/intel_rdt: Group staged configuration into a separate struct James Morse
2018-08-24 10:45 ` [RFC PATCH 04/20] x86/intel_rdt: Add closid to the staged config James Morse
2018-08-24 10:45 ` [RFC PATCH 05/20] x86/intel_rdt: make update_domains() learn the affected closids James Morse
2018-08-24 10:45 ` [RFC PATCH 06/20] x86/intel_rdt: Add a helper to read a closid's configuration for show_doms() James Morse
2018-08-24 10:45 ` [RFC PATCH 07/20] x86/intel_rdt: Expose update_domains() as an arch helper James Morse
2018-08-24 10:45 ` [RFC PATCH 08/20] x86/intel_rdt: Make cdp enable/disable global James Morse
2018-08-24 10:45 ` [RFC PATCH 09/20] x86/intel_rdt: Track the actual number of closids separately James Morse
2018-08-24 10:45 ` [RFC PATCH 10/20] x86/intel_rdt: Let resctrl change the resources's num_closid James Morse
2018-08-24 10:45 ` [RFC PATCH 11/20] x86/intel_rdt: Pass in the code/data/both configuration value when parsing James Morse
2018-08-24 10:45 ` [RFC PATCH 12/20] x86/intel_rdt: Correct the closid when staging configuration changes James Morse
2018-08-24 10:45 ` [RFC PATCH 13/20] x86/intel_rdt: Allow different CODE/DATA configurations to be staged James Morse
2018-08-24 10:45 ` [RFC PATCH 14/20] x86/intel_rdt: Add a separate resource list for resctrl James Morse
2018-08-24 10:45 ` [RFC PATCH 15/20] x86/intel_rdt: Walk the resctrl schema list instead of the arch's resource list James Morse
2018-08-24 10:45 ` [RFC PATCH 16/20] x86/intel_rdt: Move the schemata names into struct resctrl_schema James Morse
2018-08-24 10:45 ` [RFC PATCH 17/20] x86/intel_rdt: Stop using Lx CODE/DATA resources James Morse
2018-08-24 10:45 ` [RFC PATCH 18/20] x86/intel_rdt: Remove the CODE/DATA illusionary caches James Morse
2018-08-24 10:45 ` [RFC PATCH 19/20] x86/intel_rdt: Kill off alloc_enabled James Morse
2018-08-24 10:45 ` [RFC PATCH 20/20] x86/intel_rdt: Merge cdp enable/disable calls James Morse
2018-08-27 14:22 ` [RFC PATCH 00/20] x86/intel_rdt: Start abstraction for a second arch Fenghua Yu
2018-08-31 15:34 ` James Morse
2018-09-06 14:03 ` Thomas Gleixner
2018-11-27 12:33 ` Yury Norov [this message]
2018-11-30 19:23 ` James Morse
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181127123319.GA24166@yury-thinkpad \
--to=ynorov@caviumnetworks.com \
--cc=Yuri.Norov@cavium.com \
--cc=fenghua.yu@intel.com \
--cc=hpa@zytor.com \
--cc=james.morse@arm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=reinette.chatre@intel.com \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.com \
--cc=vikas.shivappa@linux.intel.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).