linux-kernel - Re: 2.6.19.2 sky2/acpi crashes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <200701232136.54731.lenb@kernel.org>
Date:	Tue, 23 Jan 2007 21:36:54 -0500
From:	Len Brown <lenb@...nel.org>
To:	"Luming Yu" <luming.yu@...il.com>
Cc:	"Lionel Landwerlin" <landwer@...e.fr>,
	linux-kernel@...r.kernel.org, venkatesh.pallipadi@...el.com
Subject: Re: 2.6.19.2 sky2/acpi crashes

> > > Apple Macbook 2GHz (x86, not amd64)

> > > > > Please try to remove processor module.
> > > >
> > > > Ok, that's done. Same problem.
> > >
> > > any difference with "idle=poll"?
> > > if yes, how about "idle=halt"?
> >
> > idle=poll seems to fix the problem (cpu fan is running almost at full
> > speed). Maybe I should run a longer test... For now it consists to run
> > about 15 torrents and watching HDTV through ethernet device.
> >
> > idle=halt does not :
> 
> It sounds like issues relative to Processor C state.
> Please enter a bug in ACPI category on bugzilla.kernel.org

Actually, the test above with the processor module removed proved
that it isn't ACPI C-states -- as they will not be available.
You should be able to observe that /proc/acpi/processor/*/power
does not indicate any C-state use when processor is unloaded.

My guess was that some deep C-state with long exit latency
was interfering with the device.  booting w/o the processor
module should have left you running the native mwait idle.
booting with idle=halt should have left you running the HLT idle.
booting with idle=poll is a busy spin loop that never enters
any hardware power saving state.

I'm quite puzzled that idle=halt was not sufficient to solve the issue,
because that should be the lowest exit latency idle loop.
So maybe I'm wrong about the cause -- though I can't then
explain why idle=poll helps...

All of the idle selection options cause the kernel to print
a line with the word "idle" in it.  Perhaps you could search
your dmesg for "idle" to verify that it is running what we
think it is?

-Len

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/