From: Borislav Petkov <bp@alien8.de>
To: Huang Rui <ray.huang@amd.com>
Cc: Sherry Hurwitz <sherry.hurwitz@amd.com>,
Peter Zijlstra <peterz@infradead.org>,
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 09:23:41 +0100 [thread overview]
Message-ID: <20160321082340.GA15904@pd.tnic> (raw)
In-Reply-To: <20160321030744.GA26269@hr-amur2>
On Mon, Mar 21, 2016 at 11:07:46AM +0800, Huang Rui wrote:
> OK, we will find some fam15h, fam16h platforms to verify it. Please
> wait for my feedback.
>
> 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, it is the cores and each core can contain two or more logical
threads. In AMD speak, that's the compute unit count. We read it in
detect_ht() from CPUID(1).EBX[23:16] which is LogicalProcessorCount,
i.e., CPUID(8000_0008).ECX[NC] + 1, i.e., the number of cores. And
"cores" in BKDG speak is the number of all cores in a processor which
are distributed across compute units....
That's why we divide by the number of siblings, i.e., the number of
cores in a CU, in AMD speak.
I know, it is confusing but once we're fine with the nomenclature, it'll
become as clear as day. :-)
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
next prev 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
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 [this message]
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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