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From: Daniel Jacobowitz <drow@false.org>
To: Dan Malek <dan@embeddededge.com>
Cc: Joakim Tjernlund <Joakim.Tjernlund@lumentis.se>,
	linuxppc-dev@lists.linuxppc.org
Subject: Re: Improved copy_page() function, about 30% speed up for mpc860!
Date: Mon, 3 Mar 2003 19:54:05 -0500	[thread overview]
Message-ID: <20030304005405.GA29518@nevyn.them.org> (raw)
In-Reply-To: <3E63F69C.80001@embeddededge.com>


On Mon, Mar 03, 2003 at 07:43:08PM -0500, Dan Malek wrote:
> Joakim Tjernlund wrote:
>
> >OK so this is not it then, but what is it then? Are you 100% that
> >the bug(whatever this may be) is present for mpc860, rev D4 or later?
> >How can I make it bite me on kernel space memory?
> >I can't find that info in the archives, if it's there please give me a
> >hint.
>
> I guess once again I don't understand the questions or failed to express
> my responses properly.
>
> In the previous message, you included a link that indicated a problem
> setting the DAR, cache instructions, and asked if this was a problem.
> In this case, due to the way we map kernel space and use the cache
> instructions,
> we have "fixed" this bug.  I believe it was found because of the way we
> copy instructions in the C library, and it affected user applications.
> The specific problem described in this link is not a problem with Linux.

That is, in fact, incorrect.  It's fatal from userland.  I experimented
with it just a couple of months ago.

Only way to sort it out would be to do instruction decoding on the
faulting address, which is hideous beyond words.

--
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

  reply	other threads:[~2003-03-04  0:54 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-03-02 17:50 Improved copy_page() function, about 30% speed up for mpc860! Joakim Tjernlund
2003-03-03 21:18 ` Dan Malek
2003-03-03 23:16   ` Joakim Tjernlund
2003-03-04  0:43     ` Dan Malek
2003-03-04  0:54       ` Daniel Jacobowitz [this message]
2003-03-04  3:38         ` Dan Malek
2003-03-04  8:29           ` Joakim Tjernlund
2003-03-04 13:33             ` Dan Malek
2003-03-04 15:24               ` Joakim Tjernlund
2003-03-04 17:00                 ` Dan Malek
2003-03-04 22:01                   ` Joakim Tjernlund
2003-03-04 22:41                     ` Dan Malek
2003-03-04 23:20                       ` Joakim Tjernlund
2003-03-04 23:35                     ` Tom Rini
2003-03-04 23:45                       ` Joakim Tjernlund
2003-03-05  0:05                         ` Tom Rini
2003-03-05  0:19                           ` Joakim Tjernlund
2003-03-05 17:12                             ` Tom Rini
2003-03-05 17:50                               ` Joakim Tjernlund
2003-03-05 17:15                       ` Dan Malek
     [not found]     ` <1046737789.885.15.camel@zion.wanadoo.fr>
2003-03-04  0:51       ` Dan Malek
  -- strict thread matches above, loose matches on Subject: below --
2003-02-27 13:08 Joakim Tjernlund
2003-02-27 15:45 ` Joakim Tjernlund
2003-02-28 17:31 ` Joakim Tjernlund
2003-03-03 21:28 ` Dan Malek
2003-03-04  0:09   ` Joakim Tjernlund
2003-03-04  0:19   ` Paul Mackerras

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