Re: [PATCH 1/2] x86/CPU/AMD: Present package as die instead of socket

From: Borislav Petkov <bp@alien8.de>
To: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	x86@kernel.org, linux-kernel@vger.kernel.org, leo.duran@amd.com,
	yazen.ghannam@amd.com, Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH 1/2] x86/CPU/AMD: Present package as die instead of socket
Date: Tue, 27 Jun 2017 18:16:57 +0200	[thread overview]
Message-ID: <20170627161657.p4kurw2f3gcavfvz@pd.tnic> (raw)
In-Reply-To: <122fd136-e3a1-1d59-87c8-a24de6b078c1@amd.com>

On Tue, Jun 27, 2017 at 10:55:52PM +0700, Suravee Suthikulpanit wrote:
> The reason we are trying to present "package == NUMA node (die)" here is
> because the topology.txt defines package to contain a number of cores plus
> shared resources (e.g. DRAM controller, shared caches, etc). Since the
> cpuinfo_x86.phys_proc_id is also defined as the physical ID of the package,

Ok, it seems we will continue talking past each other here. So let's
look at the issues separately:

 * irqbalance fails to allocating IRQs to individual CPU within the die.

Why does it fail? What is the root cause for this?

 * The scheduler fails to load-balance across 8 threads within a die
   (e.g. running 8-thread application w/ taskset -c 0-7 ) with
   the DIE schedule domain omitted due to x86_has_numa_in_package.

Why do you need to load-balance within the die? Why not load-balance
within the 0-15 threads?

What are the disadvantages of the situation now?

-- 
Regards/Gruss,
    Boris.

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