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From: "Lendacky, Thomas" <Thomas.Lendacky@amd.com>
To: Matt Fleming <matt@codeblueprint.co.uk>,
	Peter Zijlstra <peterz@infradead.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Suthikulpanit, Suravee" <Suravee.Suthikulpanit@amd.com>,
	Mel Gorman <mgorman@techsingularity.net>,
	Borislav Petkov <bp@alien8.de>
Subject: Re: [PATCH] sched/topology: Improve load balancing on AMD EPYC
Date: Tue, 11 Jun 2019 17:22:21 +0000	[thread overview]
Message-ID: <18994abb-a2a8-47f4-9a35-515165c75942@amd.com> (raw)
In-Reply-To: <20190610212620.GA4772@codeblueprint.co.uk>

On 6/10/19 4:26 PM, Matt Fleming wrote:
> On Wed, 05 Jun, at 08:00:35PM, Peter Zijlstra wrote:
>>
>> And then we had two magic values :/
>>
>> Should we not 'fix' RECLAIM_DISTANCE for EPYC or something? Because
>> surely, if we want to load-balance agressively over 30, then so too
>> should we do node_reclaim() I'm thikning.
> 
> Yeah we can fix it just for EPYC, Mel suggested that approach originally.
> 
> Suravee, Tom, what's the best way to detect these EPYC machines that need to
> override RECLAIM_DISTANCE?

You should be able to do it based on the family. There's an init_amd_zn()
function in arch/x86/kernel/cpu/amd.c.  You can add something there or,
since init_amd_zn() sets X86_FEATURE_ZEN, you could check for that if you
prefer putting it in a different location.

Thanks,
Tom

> 

  reply	other threads:[~2019-06-11 17:22 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-05 15:59 Matt Fleming
2019-06-05 18:00 ` Peter Zijlstra
2019-06-10 21:26   ` Matt Fleming
2019-06-11 17:22     ` Lendacky, Thomas [this message]
2019-06-18 10:43       ` Matt Fleming
2019-06-18 12:33         ` Peter Zijlstra
2019-06-19 21:34           ` Matt Fleming
2019-06-24 14:24             ` Mel Gorman
2019-06-26 21:18               ` Suthikulpanit, Suravee
2019-06-28 15:15                 ` Matt Fleming
2019-07-22 14:11                   ` Suthikulpanit, Suravee

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