From: Avi Kivity <avi@redhat.com>
To: "David S. Ahern" <daahern@cisco.com>
Cc: BRUNO CESAR RIBAS <ribas@c3sl.ufpr.br>,
Zachary Amsden <zamsden@redhat.com>,
Brian Jackson <iggy@theiggy.com>, kvm-devel <kvm@vger.kernel.org>
Subject: Re: RHEL5.5, 32-bit VM repeatedly locks up due to kvmclock
Date: Sat, 24 Apr 2010 21:40:42 +0300 [thread overview]
Message-ID: <4BD33B2A.1070207@redhat.com> (raw)
In-Reply-To: <4BD22B67.6030800@cisco.com>
On 04/24/2010 02:21 AM, David S. Ahern wrote:
>
> On 04/23/2010 04:21 PM, BRUNO CESAR RIBAS wrote:
>
>> Could you try hpet? I had similar problem with multicore and multiCPU (per
>> mother board) [even with constant_tsc].
>>
>> Since I changed the guest to hpet i had no more problems.
>>
> It's stable in the sense of no lockups yet, but is a much slower time
> source from a gettimeofday perspective compared to tsc and jiffies
> (based on speed jiffies appears to be tsc-based).
>
Jiffies doesn't sample any hardware; instead, a timer interrupt causes a
counter to be incremented, and that counter is sampled. The downside is
that clock granularity is very low - you can't use it for accurate timing.
--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.
prev parent reply other threads:[~2010-04-24 18:41 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-23 17:08 RHEL5.5, 32-bit VM repeatedly locks up due to kvmclock David S. Ahern
2010-04-23 20:39 ` Brian Jackson
2010-04-23 21:39 ` Zachary Amsden
2010-04-23 21:42 ` David S. Ahern
2010-04-23 22:21 ` BRUNO CESAR RIBAS
2010-04-23 23:21 ` David S. Ahern
2010-04-24 18:40 ` Avi Kivity [this message]
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