public inbox for libc-ports@sourceware.org
 help / color / mirror / Atom feed
From: Will Newton <will.newton@linaro.org>
To: Andrew Haley <aph@redhat.com>
Cc: "Carlos O'Donell" <carlos@redhat.com>,
		"libc-ports@sourceware.org" <libc-ports@sourceware.org>,
	Patch Tracking <patches@linaro.org>
Subject: Re: [PATCH] ARM: Add pointer guard support.
Date: Wed, 25 Sep 2013 19:32:00 -0000	[thread overview]
Message-ID: <CANu=DmhKf7u=L4f9ggcOuSQYBvm61L9gA5=Jvqxg+WMNDSHKnA@mail.gmail.com> (raw)
In-Reply-To: <5243165F.804@redhat.com>

On 25 September 2013 17:59, Andrew Haley <aph@redhat.com> wrote:
> On 09/25/2013 05:23 PM, Will Newton wrote:
>> From a back of the envelope calculation the cost of accessing TLS is
>> one cycle faster than accessing a global in best case (e.g.
>> Cortex-A15)
>
> Why is TLS so fast on Cortex-A15?

I don't have exact numbers but the mrc instruction used to load the
thread pointer into a general purpose register has very variable
timings depending on which core you have. A15 is the fastest of the
Cortex-A cores in this regard.


-- 
Will Newton
Toolchain Working Group, Linaro

  reply	other threads:[~2013-09-25 19:32 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-25  9:06 Will Newton
2013-09-25 16:09 ` Carlos O'Donell
2013-09-25 16:20   ` pinskia
2013-09-25 16:23   ` Will Newton
2013-09-25 16:25     ` Carlos O'Donell
2013-09-25 16:59     ` Andrew Haley
2013-09-25 19:32       ` Will Newton [this message]
2013-09-26 15:02 ` Carlos O'Donell

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='CANu=DmhKf7u=L4f9ggcOuSQYBvm61L9gA5=Jvqxg+WMNDSHKnA@mail.gmail.com' \
    --to=will.newton@linaro.org \
    --cc=aph@redhat.com \
    --cc=carlos@redhat.com \
    --cc=libc-ports@sourceware.org \
    --cc=patches@linaro.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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).