Re: [PATCH] x86: split e820 reserved entries record to late v2

David Witbrodt
2008-08-29T03:59:27Z

> From: Ingo Molnar <mingo@elte.hu>
> To: Yinghai Lu <yhlu.kernel@gmail.com>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>; David Witbrodt <dawitbro@sbcglobal.net>; Thomas Gleixner <tglx@linutronix.de>; H. Peter Anvin <hpa@zytor.com>; Andrew Morton <akpm@linux-foundation.org>; Jesse Barnes <jbarnes@virtuousgeek.org>; linux-kernel@vger.kernel.org
> Sent: Thursday, August 28, 2008 4:58:28 PM
> Subject: Re: [PATCH] x86: split e820 reserved entries record to late v2
>
>
> * Yinghai Lu wrote:
>
> > On Thu, Aug 28, 2008 at 1:40 PM, Linus Torvalds
> > wrote:
> > > On Thu, 28 Aug 2008, Yinghai Lu wrote:
> > >>
> > >> v2: insert e820 reserve resources before pnp_system_init
> > >
> > > Looks ok by me. Now it just needs testing ;)
> > >
> > > Does it actually fix the HPET regression on that odd machine (without the
> > > special hacks to recognize HPET explicitly)?
> >
> > David,
> >
> > can you test attached patch?
> > also you may try to revert the old patch.
>
> great - i've done the revert of a2bd7274b471 and have applied your patch
> and pushed it out into -tip. David, could you please test whether
> tip/master works for you out of box?

===== SHELL OUTPUT (for sanity) =====
commit e3fc96d5aca609bcf6ab0327850a109df65c1dbb
Merge: 6b8c836... a36d241...
Author: Ingo Molnar <mingo@elte.hu>
Date: Thu Aug 28 22:57:20 2008 +0200

Merge branch 'x86/core'
=====================================

Results: both ECS AMD690GM-M2 machines boot fine...

- no need for "hpet=disable"
- no error messages in 'dmesg' (except that annoying TSC b.s.)

More good news: the user who first reported the regression in May
(he uses Intel Q6600 CPU + Abit F-190HD mboard, while I use AMD
Athlon 64 X2 3600+ CPU + ECS mboard) posted a followup on his blog:

===== http://ciaranm.wordpress.com/2008/05/18/yay-for-git/#comments =====
Oh good. Looks like git head works just fine now for me, so whatever
it was appears to be fixed.

Comment by Ciaran McCreesh — August 26, 2008 @ 6:25 pm
=========================================================================

I was afraid that Yinghai's original patch (many days ago) which
worked for me was too AMD-specific, and would not work for this other
user experiencing the regression against commit 3def3d6d...

When you (Ingo) and Yinghai made it more generic afterwards, I
feared that it was too HPET-specific.

I tried to get Ciaran here, so that the problems he and I were
having could both be solved. It's not clear what change solved his
regression -- clearly it's not today's patch, since his blog post
is dated 2 days ago! -- but I'm glad to see that all is well in
the world again.

Ingo, could you do me a favor?

Mr. Anvin's inbox got badly messed up because of me:

> From: H. Peter Anvin <hpa@zytor.com>
[...]
> Sent: Thursday, August 28, 2008 8:21:09 PM
[...]
> This may be a rehash of things previously discussed in this thread; my
> email seems to be a bit flakey to the point that I don't know if I have
> gotten all the messages.

Could you explain this to him for me? I don't want to post any more than
this one message, just making a bad situation worse. (Sorry about the
threading, Peter!)

Since Monday I have gone back to work on my LAN. RAID was quickly set up
on the fileserver, but the backup of the P4 isn't finished so I _still_
haven't been able to pull the hard disk from it for the webserver. Only
after that will I be able to get the MTA arrangement I want, and banish
this webmail client FOREVER! (I should have done all of this while I was
helping you troubleshoot the regression, since my 2.6.25 kernels work fine,
but I was too excited about being able to help to think that clearly.)

Thanks all!
Dave Witbrodt