linux-um archives
 help / color / mirror / Atom feed
From: Jeff Dike <jdike@addtoit.com>
To: BlaisorBlade <blaisorblade_spam@yahoo.it>
Cc: user-mode-linux-devel@lists.sourceforge.net
Subject: Re: [uml-devel] Re: The SKAS4 patch?? + ideas for 0 context-switch
Date: Wed, 09 Jun 2004 21:52:05 -0400	[thread overview]
Message-ID: <200406100152.i5A1q5is009173@ccure.user-mode-linux.org> (raw)
In-Reply-To: Your message of "Wed, 09 Jun 2004 23:05:24 +0200." <200406092305.24447.blaisorblade_spam@yahoo.it>

blaisorblade_spam@yahoo.it said:
> I don't think that a flush of fewer TLBs would be faster; what (In My
> Ignorant  Opinion) slows things down is not clearing a buffer (it will
> probably cost 1  cycle, if they put a RESET pin in the TLBs), but
> reloading its content when  memory is read;

> Well, actually it comes to changing 2 segments descriptors (the ones
> for  USER_CS and USER_DS)

> Well, using segments here means that the CS and DS descriptor limit
> are  lowered, not that I increase base_addr - are you sure that this
> would have a  cost? Currently the check is not "disabled" - just the
> check value is MAX_PTR  (0xffff....). Yes, the CPUs could be smart
> enough to optimize the check  out...

You are being way too casual and hard-waving about all this.  I've heard
scary numbers for all of these.

> I'll try to see if Intel manuals say anything about this.

Yes, spend some quality time with the Intel manuals, and see what they say.

> Well, this is the most important one... I'll try to investigate on
> this. 

Actually, the most important factor to me is virtual address space.

				Jeff



-------------------------------------------------------
This SF.Net email is sponsored by: GNOME Foundation
Hackers Unite!  GUADEC: The world's #1 Open Source Desktop Event.
GNOME Users and Developers European Conference, 28-30th June in Norway
http://2004/guadec.org
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

  reply	other threads:[~2004-06-10  1:01 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-06-07 17:49 [uml-devel] The SKAS4 patch?? + ideas for 0 context-switch BlaisorBlade
2004-06-08  4:55 ` [uml-devel] " Jeff Dike
2004-06-09 21:05   ` BlaisorBlade
2004-06-10  1:52     ` Jeff Dike [this message]
2004-06-14 18:17     ` BlaisorBlade
2004-06-14 18:10   ` BlaisorBlade
     [not found]   ` <200406121601.35801.blaisorblade_spam@yahoo.it>
2004-06-15  3:39     ` Jeff Dike

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=200406100152.i5A1q5is009173@ccure.user-mode-linux.org \
    --to=jdike@addtoit.com \
    --cc=blaisorblade_spam@yahoo.it \
    --cc=user-mode-linux-devel@lists.sourceforge.net \
    /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