linux-kernel - Re: One-shot high-resolution POSIX timer periodically late

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 for Android: free password hash cracker in your pocket

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

Date:	Tue, 6 Feb 2007 13:37:16 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	John <shill@...e.fr>
Cc:	linux-kernel@...r.kernel.org, tglx@...esys.com,
	johnstul@...ibm.com, akpm@...l.org
Subject: Re: One-shot high-resolution POSIX timer periodically late


* John <shill@...e.fr> wrote:

> > 2.6.18-rt7 is pretty old, do you see the problem in 2.6.20-rc6-rt5 
> > too?
> 
> Ingo, Thomas,
> 
> I cannot reproduce in 2.6.20-rc6-rt6, but it is not strictly an 
> apples-to-apples comparison because I get a tsc clocksource in 
> 2.6.20-rc6-rt6, and an acpi_pm clocksource in 2.6.18.6-rt7.

that suggests that the TSC was not deemed reliable by the newer kernel - 
which almost always means it's not realiable. I think the problems you 
were seeing are consistent with TSC being non-monotonic - so the fix is 
to not use the TSC - and the newer kernel does this automatically.

	Ingo
-
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/