From: "H. Peter Anvin" <hpa@zytor.com>
To: Timothy Miller <miller@techsource.com>
Cc: Ulrich Drepper <drepper@redhat.com>, linux-kernel@vger.kernel.org
Subject: Re: hammer: MAP_32BIT
Date: Fri, 09 May 2003 16:24:12 -0700 [thread overview]
Message-ID: <3EBC389C.2010601@zytor.com> (raw)
In-Reply-To: <3EBC2FD7.2080007@techsource.com>
Timothy Miller wrote:
>>
>> The purpose is that there is a slight task-switching speed advantage if
>> the address is in the bottom 4 GB. Since this affects every process,
>> and most processes use very little TLS, this is worthwhile.
>>
>> This is fundamentally due to a K8 design flaw.
>
> Is there an explicit check somewhere for this? Are the page tables laid
> out differently?
>
No, there are two ways to load the FS base register: use a descriptor,
which is limited to 4 GB but is faster, or WRMSR, which is slower, but
unlimited.
-hpa
next prev parent reply other threads:[~2003-05-09 23:12 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-05-09 7:35 hammer: MAP_32BIT Ulrich Drepper
2003-05-09 9:20 ` Andi Kleen
2003-05-09 11:28 ` mikpe
2003-05-09 11:38 ` Andi Kleen
2003-05-09 11:52 ` mikpe
2003-05-09 12:16 ` Andi Kleen
2003-05-09 18:11 ` H. Peter Anvin
2003-05-09 19:24 ` Ulrich Drepper
2003-05-09 20:55 ` H. Peter Anvin
2003-05-09 21:45 ` Ulrich Drepper
2003-05-09 22:07 ` H. Peter Anvin
2003-05-09 22:20 ` Ulrich Drepper
2003-05-09 22:21 ` H. Peter Anvin
2003-05-09 22:20 ` Timothy Miller
2003-05-09 22:20 ` H. Peter Anvin
2003-05-09 22:46 ` Timothy Miller
2003-05-09 23:24 ` H. Peter Anvin [this message]
2003-05-13 14:25 ` Timothy Miller
2003-05-09 22:22 ` Ulrich Drepper
2003-05-09 22:53 ` Timothy Miller
2003-05-09 23:24 ` Ulrich Drepper
2003-05-10 0:00 ` Edgar Toernig
2003-05-10 0:58 ` Ulrich Drepper
2003-05-10 2:51 ` Edgar Toernig
2003-05-09 17:36 ` H. Peter Anvin
2003-05-09 17:39 ` Ulrich Drepper
2003-05-10 1:48 ` Andi Kleen
2003-05-10 20:10 ` David Woodhouse
2003-05-13 18:54 ` H. Peter Anvin
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=3EBC389C.2010601@zytor.com \
--to=hpa@zytor.com \
--cc=drepper@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=miller@techsource.com \
/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