linux-kernel - Re: [PATCH V4 0/5] x86/mbm : Intel Memory Bandwidth monitoring support

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Message-ID: <alpine.DEB.2.10.1602171049000.3157@vshiva-Udesk>
Date:	Wed, 17 Feb 2016 10:52:49 -0800 (PST)
From:	Vikas Shivappa <vikas.shivappa@...el.com>
To:	Vikas Shivappa <vikas.shivappa@...ux.intel.com>
cc:	vikas.shivappa@...el.com, x86@...nel.org,
	linux-kernel@...r.kernel.org, hpa@...or.com, tglx@...utronix.de,
	mingo@...nel.org, peterz@...radead.org, ravi.v.shankar@...el.com,
	tony.luck@...el.com, fenghua.yu@...el.com,
	kanaka.d.juvva@...el.com, h.peter.anvin@...el.com
Subject: Re: [PATCH V4 0/5] x86/mbm : Intel Memory Bandwidth monitoring
 support


Hello Thomas,

Was wondering if you had any feedback on the MBM patches. These are almost a 
complete rewrite (the core part 3/5 from Tony Luck). The reused parts are mostly 
the declarations of datastructures. This has tried to address all your comments on 
V3 about the commenting, the core calculation, init, lot of unnecessary 
and confusing constants and code..

http://lkml.kernel.org/r/alpine.DEB.2.11.1508192243081.3873@nanos

Thanks,
Vikas

On Wed, 10 Feb 2016, Vikas Shivappa wrote:

> The V4 version of MBM is almost a complete rewrite of the prior
> versions. It tries to address all of Thomas earlier
> comments.
>
> The patch series has one preparatory patch for cqm and then 4 MBM
> patches. *Patches apply on 4.5-rc1*.
>
> Memory bandwitdh monitoring(MBM) provides OS/VMM a way to monitor
> bandwidth from one level of cache to another. The current patches
> support L3 external bandwitch monitoring.
> It supports both 'local bandwidth' and 'total bandwidth' monitoring for
> the socket. Local bandwidth measures the amount of data sent through
> the memory controller on the socket and total b/w measures the total
> system bandwidth.
>
> The tasks are associated with a Resouce Monitoring ID(RMID) just like in
> cqm and OS uses a MSR write to indicate the RMID of the task during
> scheduling.
>
>
> [PATCH 1/5] x86,perf/cqm : Fix cqm handling of grouping events into a
> [PATCH 2/5] x86/mbm: Intel Memory B/W Monitoring enumeration and init
> [PATCH 3/5] x86/mbm: Memory bandwidth monitoring event management
> [PATCH 4/5] x86/mbm: RMID Recycling MBM changes
> [PATCH 5/5] x86/mbm: Add support for MBM counter overflow handling
>