public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Borislav Petkov <bp@alien8.de>
To: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de,
	mingo@redhat.com
Subject: Re: [PATCH] x86/CPU/AMD: Fix LLC ID bit-shift calculation
Date: Mon, 18 Jun 2018 19:20:48 +0200	[thread overview]
Message-ID: <20180618172048.GD24921@zn.tnic> (raw)
In-Reply-To: <1528915390-30533-1-git-send-email-suravee.suthikulpanit@amd.com>

On Wed, Jun 13, 2018 at 01:43:10PM -0500, Suravee Suthikulpanit wrote:
> The current logic incorrectly calculates the LLC ID from the APIC ID.
> Unless specified otherwise, the LLC ID should be calculated from
> the count order of the number of threads sharing cache.

Don't you mean:

"... should be calculated by removing the Core and Thread ID bits"?

here?

I'm looking at

"2.1.10.2.1.3 ApicId Enumeration Requirements

...

Each Core::X86::Apic::ApicId[ApicId] register is preset as follows:
• ApicId[6] = Socket ID.
• ApicId[5:4] = Node ID.
• ApicId[3] = Logical CCX L3 complex ID
• ApicId[2:0]= (SMT) ? {LogicalCoreID[1:0],ThreadId} : {1'b0,LogicalCoreID[1:0]}.

and in order to get a unique LLC ID, you simply need to shift out the
CoreID and the ThreadId, right?

Or am I misreading it?

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

  reply	other threads:[~2018-06-18 17:20 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-13 18:43 [PATCH] x86/CPU/AMD: Fix LLC ID bit-shift calculation Suravee Suthikulpanit
2018-06-18 17:20 ` Borislav Petkov [this message]
2018-06-18 18:14   ` Suthikulpanit, Suravee
2018-06-18 18:23     ` Borislav Petkov
2018-06-18 18:46       ` Suthikulpanit, Suravee
2018-06-18 18:57         ` Borislav Petkov
2018-06-22 19:24 ` [tip:x86/urgent] " tip-bot for Suravee Suthikulpanit

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180618172048.GD24921@zn.tnic \
    --to=bp@alien8.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=suravee.suthikulpanit@amd.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox