archive mirror
 help / color / mirror / Atom feed
From: Adrian Bunk <>
To: Andi Kleen <>
Subject: Re: [PATCH] Support worst case cache line sizes as config option
Date: Mon, 28 Apr 2003 14:19:20 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <20030428114717.GA6904@averell>

On Mon, Apr 28, 2003 at 01:47:17PM +0200, Andi Kleen wrote:
> On Mon, Apr 28, 2003 at 11:16:16AM +0200, Adrian Bunk wrote:
> > Your X86_GENERIC is semantically equivalent to M386.
> M386 is tuning for the Intel 386
> X86_GENERIC is "try to tune for all CPUs if possible" 

M386 says that the minimum CPU supported is the 386 - and all CPUs 
above are supported, too. E.g.:

config X86_PPRO_FENCE
        depends on M686 || M586MMX || M586TSC || M586 || M486 || M386
        default y

config X86_F00F_BUG
        depends on M586MMX || M586TSC || M586 || M486 || M386
        default y

> > This doesn't work. E.g. MPENTIUMIII has the semantics of "support 
> > Pentium-III and above". If you want to compile a kernel that runs on 
> > both a Pentium-III and a Pentium-4 you choose MPENTIUMIII which implies 
> > X86_L1_CACHE_SHIFT=5 ...
> Admittedly the other options could be changed to 
> default "4" if (MELAN || M486 || M386) && !X86_GENERIC
> but that looked a bit too ugly and it seems to work even without.

Your approach as well as the approach I'm currently working on breaks
the current semantics that a plain M386 produces a kernel that runs on
all CPUs.

> -Andi



       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

  reply	other threads:[~2003-04-28 12:07 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-04-27  2:23 [PATCH] Support worst case cache line sizes as config option Andi Kleen
     [not found] ` <BKEGKPICNAKILKJKMHCAAEPNCIAA.Riley@Williams.Name>
2003-04-27 12:52   ` Andi Kleen
2003-04-28  9:16 ` Adrian Bunk
2003-04-28 11:47   ` Andi Kleen
2003-04-28 12:19     ` Adrian Bunk [this message]
2003-04-28 12:48       ` Jamie Lokier
2003-04-28 22:00       ` Andi Kleen

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:

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

  git send-email \ \ \ \ \ \

* 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 NNTP newsgroup(s).