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From: Peter Zijlstra <peterz@infradead.org>
To: Huang Rui <ray.huang@amd.com>
Cc: Borislav Petkov <bp@alien8.de>,
	Sherry Hurwitz <sherry.hurwitz@amd.com>,
	tglx@linutronix.de, linux-kernel@vger.kernel.org,
	mingo@kernel.org, aherrmann@suse.com, jencce.kernel@gmail.com,
	Gang Long <gang.long@amd.com>
Subject: Re: [PATCH 2/3] x86/topology: Fix AMD core count
Date: Mon, 21 Mar 2016 09:21:29 +0100	[thread overview]
Message-ID: <20160321082129.GP6344@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20160321030744.GA26269@hr-amur2>

On Mon, Mar 21, 2016 at 11:07:46AM +0800, Huang Rui wrote:
> > > The issue is that Linux assumes:
> > > 
> > > 	nr_logical_cpus = nr_cores * nr_siblings
> > > 
> > > But AMD reports its CU unit as 2 cores, but then sets num_smp_siblings
> > > to 2 as well.

> But I am confused with c->x86_max_cores /= smp_num_siblings, what is
> the real meaning of c->x86_max_cores here for AMD, the whole compute
> unit numbers per socket?

Yes, with the whole Compute Unit being the Core, each logical CPU
becomes a Thread. This is the direct consequence of using the SMT
topology to model the CU thing.

  parent reply	other threads:[~2016-03-21  8:23 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-18 15:03 [PATCH 0/3] x86 topology fixes Peter Zijlstra
2016-03-18 15:03 ` [PATCH 1/3] x86/topology: Fix logical pkg mapping Peter Zijlstra
2016-03-19  9:30   ` [tip:x86/urgent] x86/topology: Fix logical package mapping tip-bot for Peter Zijlstra
2016-03-18 15:03 ` [PATCH 2/3] x86/topology: Fix AMD core count Peter Zijlstra
2016-03-18 16:41   ` Borislav Petkov
2016-03-21  3:07     ` Huang Rui
2016-03-21  3:46       ` Huang Rui
2016-03-21  8:26         ` Borislav Petkov
2016-03-21  9:18           ` Huang Rui
2016-03-21  8:56         ` Thomas Gleixner
2016-03-21  8:21       ` Peter Zijlstra [this message]
2016-03-21  9:46         ` Huang Rui
2016-03-21 13:57           ` Borislav Petkov
2016-03-22  8:10             ` Sherry Hurwitz
2016-03-22 11:22               ` Borislav Petkov
2016-03-21  8:23       ` Borislav Petkov
2016-03-21 10:05         ` Huang Rui
2016-03-21 10:23           ` Borislav Petkov
2016-03-19  9:24   ` Thomas Gleixner
2016-03-19 15:56     ` Borislav Petkov
2016-03-20 10:39     ` Peter Zijlstra
2016-03-20 11:04       ` Borislav Petkov
2016-03-20 12:32         ` Peter Zijlstra
2016-03-20 12:46           ` Peter Zijlstra
2016-03-20 13:09             ` Borislav Petkov
2016-03-20 17:08               ` Peter Zijlstra
2016-03-20 18:46                 ` Borislav Petkov
2016-03-29  8:49             ` [tip:x86/urgent] perf/x86/amd: Cleanup Fam10h NB event constraints tip-bot for Peter Zijlstra
2016-03-22  7:56   ` [PATCH 2/3] x86/topology: Fix AMD core count Huang Rui
2016-03-18 15:03 ` [PATCH 3/3] x86/topology: Fix Intel HT disable Peter Zijlstra
2016-03-19  9:31   ` [tip:x86/urgent] " tip-bot for Peter Zijlstra
  -- strict thread matches above, loose matches on Subject: below --
2016-03-16  6:48 4.5.0+ panic when setup loop device Xiong Zhou
2016-03-16 15:26 ` Thomas Gleixner
2016-03-17  1:56   ` Xiong Zhou
2016-03-17  9:52     ` Peter Zijlstra
2016-03-17  9:56       ` Peter Zijlstra
2016-03-17 10:21       ` Thomas Gleixner
2016-03-17 10:26         ` Peter Zijlstra
2016-03-17 11:39           ` Thomas Gleixner
2016-03-17 11:51             ` Peter Zijlstra
2016-03-17 11:57               ` Borislav Petkov
2016-03-17 12:01               ` Thomas Gleixner
2016-03-17 16:42                 ` Jens Axboe
2016-03-17 18:26                   ` Jens Axboe
2016-03-17 20:20                     ` Thomas Gleixner
2016-03-17 20:23                       ` Jens Axboe
2016-03-17 20:30                         ` Thomas Gleixner
2016-03-17 20:41                           ` Jens Axboe
2016-03-18  2:31             ` Xiong Zhou
2016-03-18  4:11       ` Mike Galbraith
2016-03-18  7:51         ` Peter Zijlstra
2016-03-18 10:15         ` Peter Zijlstra
2016-03-18 12:39           ` Mike Galbraith
2016-03-18 13:32             ` Peter Zijlstra
2016-03-18 14:07               ` Mike Galbraith
2016-03-18 11:55         ` Thomas Gleixner
2016-03-18 12:39           ` Mike Galbraith
2016-03-19  9:31           ` [tip:x86/urgent] x86/topology: Use total_cpus not nr_cpu_ids for logical packages tip-bot for Thomas Gleixner
2016-03-29  8:48       ` [tip:x86/urgent] x86/topology: Fix AMD core count tip-bot for Peter Zijlstra

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