From: "Paul Rolland" <rol@witbe.net>
To: Jiri Slaby <jslaby@suse.cz>
Cc: LKML <linux-kernel@vger.kernel.org>,
clemens@ladisch.de, venki@google.com,
Thomas Gleixner <tglx@linutronix.de>,
the arch/x86 maintainers <x86@kernel.org>,
rol@witbe.net
Subject: Re: HPET causes tasks to freeze (still in 2.6.36-rc6)
Date: Mon, 4 Oct 2010 17:55:06 +0200 [thread overview]
Message-ID: <20101004175506.3e6b8c2b@tux.DEF.witbe.net> (raw)
In-Reply-To: <4CA9F471.2080704@suse.cz>
Hello,
On Mon, 04 Oct 2010 17:36:17 +0200
Jiri Slaby <jslaby@suse.cz> wrote:
> HPET as a clocksource has still issues in the latest kernels (confirmed
> in 2.6.36-rc6) at least on x86_64. Unless clocksource=jiffies,
> clocksource=tsc or nolapic_timer is used, the system is unusable. Tasks
> are not woken unless mouse is moved, key is pressed (or other hard irq
> triggered). 2.6.32 seems to be the last working.
>
> The bug was originally reported in the bugzilla here:
> https://bugzilla.novell.com/show_bug.cgi?id=579932
>
> To quote:
> "My clock is seriously lagging behind. After having used hpet for 10.5
> hours now, the clock is 5.5 hours too late!"
>
> dmesg is attached. Any ideas what's still wrong with HPET?
I've been experiencing that also with some Supermicro servers...
and last week, I switched to 2.6.35.5, which is now no more exhibiting this
weird behavior, but it may be because the machine has elected tsc as its
clocksource.
I must also say that kernels before 2.6.35.5 (namely 2.6.28.9) were showing
this strange behavior whatever clocksource I was using, so it was not
specifically HPET-related, but the "Tasks are not woken unless mouse is moved,
key is pressed (or other hard irq triggered)" part was exactly what i was
experiencing.
Paul
next prev parent reply other threads:[~2010-10-04 16:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-04 15:36 Jiri Slaby
2010-10-04 15:55 ` Paul Rolland [this message]
2010-10-04 16:31 ` Thomas Gleixner
2010-10-11 22:02 ` Jiri Slaby
2010-10-20 9:38 ` Jiri Slaby
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