Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 10 Jun 2019 22:26:20 +0100
From:   Matt Fleming <matt@codeblueprint.co.uk>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     linux-kernel@vger.kernel.org,
        "Suthikulpanit, Suravee" <Suravee.Suthikulpanit@amd.com>,
        Mel Gorman <mgorman@techsingularity.net>,
        "Lendacky, Thomas" <Thomas.Lendacky@amd.com>,
        Borislav Petkov <bp@alien8.de>
Subject: Re: [PATCH] sched/topology: Improve load balancing on AMD EPYC
Message-ID: <20190610212620.GA4772@codeblueprint.co.uk>
References: <20190605155922.17153-1-matt@codeblueprint.co.uk>
 <20190605180035.GA3402@hirez.programming.kicks-ass.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20190605180035.GA3402@hirez.programming.kicks-ass.net>
User-Agent: Mutt/1.5.24 (2015-08-30)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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?