linux-kernel - Re: [PATCH 1/6] x86/intel_rdt/mba_sc: Add documentation for MBA software controller

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 4 Apr 2018 11:30:41 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Shivappa Vikas <vikas.shivappa@...el.com>
cc:     Vikas Shivappa <vikas.shivappa@...ux.intel.com>,
        tony.luck@...el.com, ravi.v.shankar@...el.com,
        fenghua.yu@...el.com, sai.praneeth.prakhya@...el.com,
        x86@...nel.org, hpa@...or.com, linux-kernel@...r.kernel.org,
        ak@...ux.intel.com
Subject: Re: [PATCH 1/6] x86/intel_rdt/mba_sc: Add documentation for MBA
 software controller

On Tue, 3 Apr 2018, Shivappa Vikas wrote:
> On Tue, 3 Apr 2018, Thomas Gleixner wrote:
> >  The proposed new interface has no upper limit. The existing percentage
> >  based implementation has at least some notion of limit and scale; not
> >  really helpful either because of the hardware implementation. but I
> > 
> >  How is the poor admin supposed to configure that new thing without
> >  knowing what the actual hardware limits are in the first place?
> 
> That is true. The default values only put it to a very high bandwidth which
> means user gets to use everything. There seems no other way other than
> caliberating to know the actual max bandwidth in bytes. That could be a better
> value to have as default so admin knows the limit. I will explore if there is
> a way to calculate the same without caliberating.

Right, ideally we get that information from the hardware.

Thanks,

	tglx