From: Andrea Arcangeli <andrea@suse.de>
To: Bill Davidsen <davidsen@tmr.com>
Cc: Dave Jones <davej@suse.de>, Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: 2.4.19pre3aa2
Date: Thu, 14 Mar 2002 17:12:59 +0100 [thread overview]
Message-ID: <20020314171259.I22054@dualathlon.random> (raw)
In-Reply-To: <20020314133223.B19636@suse.de> <Pine.LNX.3.96.1020314104230.9248A-100000@gatekeeper.tmr.com>
In-Reply-To: <Pine.LNX.3.96.1020314104230.9248A-100000@gatekeeper.tmr.com>
On Thu, Mar 14, 2002 at 10:53:01AM -0500, Bill Davidsen wrote:
> On Thu, 14 Mar 2002, Dave Jones wrote:
>
> > On Thu, Mar 14, 2002 at 03:28:01AM +0100, Andrea Arcangeli wrote:
> > > Only in 2.4.19pre3aa2: 21_pte-highmem-f00f-1
> > >
> > > vmalloc called before smp_init was an hack, right way
> > > is to use fixmap. CONFIG_M686 doesn't mean much these
> > > days, but it's ok and probably most vendors will use it
> > > for the smp kernels, so it will save 4096 of the vmalloc space.
> > > I just didn't wanted to clobber the code with || CONFIG_K7 ||
> > > CONFIG_... | ... given all the other f00f stuff is also
> > > conditional only to M686 and probably nobody bothered to compile
> > > it out for my same reason
> >
> > Brian Gerst had a patch a few months back to introduce a CONFIG_F00F
> > if a relevant CONFIG_Mxxx was chosen[1]. It never got applied anywhere, but makes
> > more sense than the CONFIG_M686 we currently use.
> >
> > [1] 386/486/586. With addition of my Vendor choice menu, we could even further
> > narrow it down to Intel only.
>
> Since vendors (and consultants) like to build a single kernel for use on
> multiple machines, it would be nice if this could be done by some init
> code (released) and a module. I don't know what the overhead would be,
> perhaps the runtime code is so small it's not worth doing. Does that mean
Correct. I think the CONFIG option isn't worthwhile in the first place
and this is why I only left the CONFIG_M686 knowing most smp kernels are
compiled that way. 4096bytes of virtual vmallc space and some houndred
bytes of bytecode doesn't worth the config option. If something the
CONFIG_F00F would be more a documentation effort 8). But nevertheless if
somebody really cares, that still make sense and it doesn't hurt. At the
very least it is better than the current halfway broken CONFIG_M686.
But personally I'm not going to implement it and if I would really be
bothered by the halfway broken CONFIG_M686 I would drop it instead.
> it's not worth doing the option either? It certainly would seen desirable
> to check for the F00F bug and if the code to handle it was not present
> refuse to boot right away.
>
> The code actually looks so small as to be unworthy of an option, given
> that many people would set it off not knowing was it was much less whether
> they needed it. This is not like a missing FPU where you can do a graceful
> reject of the instructions, if you have the bug and not the fix you are
> vulnerable to sudden total failures, correct?
>
> --
> bill davidsen <davidsen@tmr.com>
> CTO, TMR Associates, Inc
> Doing interesting things with little computers since 1979.
Andrea
next prev parent reply other threads:[~2002-03-14 16:14 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-03-14 2:28 2.4.19pre3aa2 Andrea Arcangeli
2002-03-14 12:32 ` 2.4.19pre3aa2 Dave Jones
2002-03-14 12:37 ` 2.4.19pre3aa2 Andrea Arcangeli
2002-03-14 12:46 ` 2.4.19pre3aa2 Jeff Garzik
2002-03-14 12:59 ` 2.4.19pre3aa2 Dave Jones
2002-03-14 15:53 ` 2.4.19pre3aa2 Bill Davidsen
2002-03-14 16:12 ` Andrea Arcangeli [this message]
2002-03-14 16:16 ` 2.4.19pre3aa2 Dave Jones
2002-03-14 16:32 ` 2.4.19pre3aa2 Andrea Arcangeli
2002-03-16 1:26 ` 2.4.19pre3aa2 Mike Fedyk
2002-03-14 16:13 ` 2.4.19pre3aa2 Dave Jones
2002-03-14 17:16 ` 2.4.19pre3aa2 Bill Davidsen
2002-03-14 21:16 ` 2.4.19pre3aa2 H. Peter Anvin
2002-03-14 18:00 ` 2.4.19pre3aa2 Andrew Morton
2002-03-14 22:57 ` 2.4.19pre3aa2 Jari Ruusu
2002-03-15 10:56 ` 2.4.19pre3aa2 Jens Axboe
2002-03-15 11:06 ` 2.4.19pre3aa2 Jens Axboe
2002-03-15 17:35 ` 2.4.19pre3aa2 Jari Ruusu
2002-03-15 17:57 ` 2.4.19pre3aa2 Andrea Arcangeli
2002-03-16 12:10 ` 2.4.19pre3aa2 Jari Ruusu
2002-03-16 13:54 ` 2.4.19pre3aa2 Andrea Arcangeli
2002-03-18 19:13 ` 2.4.19pre3aa2 Jens Axboe
2002-03-19 23:26 ` 2.4.19pre3aa2 Jari Ruusu
2002-03-20 7:54 ` 2.4.19pre3aa2 Jens Axboe
2002-03-20 18:16 ` 2.4.19pre3aa2 Jari Ruusu
2002-03-20 14:21 ` 2.4.19pre3aa2 Herbert Valerio Riedel
2002-03-15 12:19 ` 2.4.19pre3aa2 Herbert Valerio Riedel
2002-03-15 17:36 ` 2.4.19pre3aa2 Jari Ruusu
2002-03-15 18:36 ` 2.4.19pre3aa2 Herbert Valerio Riedel
2002-03-16 12:12 ` 2.4.19pre3aa2 Jari Ruusu
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