linux-kernel - Re: [RFC] Fast assurate clock readable from user space and NMI handler

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]

Date:	Tue, 27 Feb 2007 01:59:43 -0800
From:	Daniel Walker <dwalker@...sta.com>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>,
	mbligh@...gle.com, linux-kernel@...r.kernel.org,
	johnstul@...ibm.com, Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [RFC] Fast assurate clock readable from user space and NMI
	handler

On Tue, 2007-02-27 at 07:29 +0100, Ingo Molnar wrote:
> * Daniel Walker <dwalker@...sta.com> wrote:
> 
> > The pit clocksource could be dropped pretty easy with my clocksource 
> > update patches, which I'm still working on but you could easily drop 
> > clock sources that aren't atomic like the pit .. Also the pit is 
> > generally undesirable, so it's not going to be missed.
> 
> that's totally unacceptable, and i'm amazed you are even suggesting it - 
> often the PIT ends up being the most reliable hardware clock in a PC. 
> Btw., what's wrong with the spinlock that is protecting PIT access? It 
> expresses the non-atomic property of the PIT just fine.

Just considering the rating is lower than the acpi_pm (and the TSC), and
it's not even considered on SMP systems is enough for me .. It's just a
problematic clock.. 

Again, I'm not suggesting we drop it all the time, just for a special
case when Mathieu needs it dropped.

Daniel

-
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/