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From: Thomas Gleixner <tglx@linutronix.de>
To: Reinette Chatre <reinette.chatre@intel.com>
Cc: fenghua.yu@intel.com, tony.luck@intel.com,
	gavin.hindman@intel.com, vikas.shivappa@linux.intel.com,
	dave.hansen@intel.com, mingo@redhat.com, hpa@zytor.com,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH V2 13/22] x86/intel_rdt: Support schemata write - pseudo-locking core
Date: Tue, 27 Feb 2018 16:38:59 +0100 (CET)	[thread overview]
Message-ID: <alpine.DEB.2.21.1802271553560.1886@nanos.tec.linutronix.de> (raw)
In-Reply-To: <alpine.DEB.2.21.1802271109300.1886@nanos.tec.linutronix.de>

On Tue, 27 Feb 2018, Thomas Gleixner wrote:
> On Mon, 26 Feb 2018, Reinette Chatre wrote:
> > Moving to "exclusive" mode it appears that, when enabled for a resource
> > group, all domains of all resources are forced to have an "exclusive"
> > region associated with this resource group (closid). This is because the
> > schemata reflects the hardware settings of all resources and their
> > domains and the hardware does not accept a "zero" bitmask. A user thus
> > cannot just specify a single region of a particular cache instance as
> > "exclusive". Does this match your intention wrt "exclusive"?
> 
> Interesting question. I really did not think about that yet. 

Actually we could solve that problem similar to the locked one and share
most of the functionality:

mkdir group
echo exclusive > mode
echo L3:0 > restrict

and for locked:

mkdir group
echo locksetup > mode
echo L2:0 > restrict
echo 'L2:0=0xf' > schemata
echo locked > mode

The 'restrict' file (feel free to come up with a better name) is only
available/writeable in exclusive and locksetup mode. In case of exclusive
mode it can contain several domains/resources, but in locked mode its only
allowed to contain a single domain/resource.

A write to schemata for exclusive or locksetup mode will apply the
exclusiveness restrictions only to the resources/domains selected in the
'restrict' file. 

Thanks,

	tglx

  reply	other threads:[~2018-02-27 15:39 UTC|newest]

Thread overview: 65+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-13 15:46 [RFC PATCH V2 00/22] Intel(R) Resource Director Technology Cache Pseudo-Locking enabling Reinette Chatre
2018-02-13 15:46 ` [RFC PATCH V2 01/22] x86/intel_rdt: Documentation for Cache Pseudo-Locking Reinette Chatre
2018-02-19 20:35   ` Thomas Gleixner
2018-02-19 22:15     ` Reinette Chatre
2018-02-19 22:19       ` Thomas Gleixner
2018-02-19 22:24         ` Reinette Chatre
2018-02-19 21:27   ` Randy Dunlap
2018-02-19 22:21     ` Reinette Chatre
2018-02-13 15:46 ` [RFC PATCH V2 02/22] x86/intel_rdt: Make useful functions available internally Reinette Chatre
2018-02-13 15:46 ` [RFC PATCH V2 03/22] x86/intel_rdt: Introduce hooks to create pseudo-locking files Reinette Chatre
2018-02-13 15:46 ` [RFC PATCH V2 04/22] x86/intel_rdt: Introduce test to determine if closid is in use Reinette Chatre
2018-02-13 15:46 ` [RFC PATCH V2 05/22] x86/intel_rdt: Print more accurate pseudo-locking availability Reinette Chatre
2018-02-13 15:46 ` [RFC PATCH V2 06/22] x86/intel_rdt: Create pseudo-locked regions Reinette Chatre
2018-02-19 20:57   ` Thomas Gleixner
2018-02-19 23:02     ` Reinette Chatre
2018-02-19 23:16       ` Thomas Gleixner
2018-02-20  3:21         ` Reinette Chatre
2018-02-13 15:46 ` [RFC PATCH V2 07/22] x86/intel_rdt: Connect pseudo-locking directory to operations Reinette Chatre
2018-02-13 15:46 ` [RFC PATCH V2 08/22] x86/intel_rdt: Introduce pseudo-locking resctrl files Reinette Chatre
2018-02-19 21:01   ` Thomas Gleixner
2018-02-13 15:46 ` [RFC PATCH V2 09/22] x86/intel_rdt: Discover supported platforms via prefetch disable bits Reinette Chatre
2018-02-13 15:46 ` [RFC PATCH V2 10/22] x86/intel_rdt: Disable pseudo-locking if CDP enabled Reinette Chatre
2018-02-13 15:46 ` [RFC PATCH V2 11/22] x86/intel_rdt: Associate pseudo-locked regions with its domain Reinette Chatre
2018-02-19 21:19   ` Thomas Gleixner
2018-02-19 23:00     ` Reinette Chatre
2018-02-19 23:19       ` Thomas Gleixner
2018-02-20  3:17         ` Reinette Chatre
2018-02-20 10:00           ` Thomas Gleixner
2018-02-20 16:02             ` Reinette Chatre
2018-02-20 17:18               ` Thomas Gleixner
2018-02-13 15:46 ` [RFC PATCH V2 12/22] x86/intel_rdt: Support CBM checking from value and character buffer Reinette Chatre
2018-02-13 15:46 ` [RFC PATCH V2 13/22] x86/intel_rdt: Support schemata write - pseudo-locking core Reinette Chatre
2018-02-20 17:15   ` Thomas Gleixner
2018-02-20 18:47     ` Reinette Chatre
2018-02-20 23:21       ` Thomas Gleixner
2018-02-21  1:58         ` Mike Kravetz
2018-02-21  6:10           ` Reinette Chatre
2018-02-21  8:34           ` Thomas Gleixner
2018-02-21  5:58         ` Reinette Chatre
2018-02-27  0:34     ` Reinette Chatre
2018-02-27 10:36       ` Thomas Gleixner
2018-02-27 15:38         ` Thomas Gleixner [this message]
2018-02-27 19:52         ` Reinette Chatre
2018-02-27 21:33           ` Reinette Chatre
2018-02-28 18:39           ` Thomas Gleixner
2018-02-28 19:17             ` Reinette Chatre
2018-02-28 19:40               ` Thomas Gleixner
2018-02-27 21:01     ` Reinette Chatre
2018-02-28 17:57       ` Thomas Gleixner
2018-02-28 17:59         ` Thomas Gleixner
2018-02-28 18:34           ` Reinette Chatre
2018-02-28 18:42             ` Thomas Gleixner
2018-02-13 15:46 ` [RFC PATCH V2 14/22] x86/intel_rdt: Enable testing for pseudo-locked region Reinette Chatre
2018-02-13 15:46 ` [RFC PATCH V2 15/22] x86/intel_rdt: Prevent new allocations from pseudo-locked regions Reinette Chatre
2018-02-13 15:47 ` [RFC PATCH V2 16/22] x86/intel_rdt: Create debugfs files for pseudo-locking testing Reinette Chatre
2018-02-13 15:47 ` [RFC PATCH V2 17/22] x86/intel_rdt: Create character device exposing pseudo-locked region Reinette Chatre
2018-02-13 15:47 ` [RFC PATCH V2 18/22] x86/intel_rdt: More precise L2 hit/miss measurements Reinette Chatre
2018-02-13 15:47 ` [RFC PATCH V2 19/22] x86/intel_rdt: Support L3 cache performance event of Broadwell Reinette Chatre
2018-02-13 15:47 ` [RFC PATCH V2 20/22] x86/intel_rdt: Limit C-states dynamically when pseudo-locking active Reinette Chatre
2018-02-13 15:47 ` [RFC PATCH V2 21/22] mm/hugetlb: Enable large allocations through gigantic page API Reinette Chatre
2018-02-13 15:47 ` [RFC PATCH V2 22/22] x86/intel_rdt: Support contiguous memory of all sizes Reinette Chatre
2018-02-14 18:12 ` [RFC PATCH V2 00/22] Intel(R) Resource Director Technology Cache Pseudo-Locking enabling Mike Kravetz
2018-02-14 18:31   ` Reinette Chatre
2018-02-15 20:39     ` Reinette Chatre
2018-02-15 21:10       ` Mike Kravetz

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