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From: Avi Kivity <avi@redhat.com>
To: kvm-ia64@vger.kernel.org
Subject: Re: switching from KVM guest to the host .... TLBs not present?
Date: Thu, 16 Apr 2009 08:59:15 +0000	[thread overview]
Message-ID: <49E6F363.3040908@redhat.com> (raw)
In-Reply-To: <49DE0856.8010700@sgi.com>

Jes Sorensen wrote:
> Avi Kivity wrote:
>> Applied, but I note that entering the guest with any lock held is 
>> problematic, as the guest may spend an arbitrary amount of time in 
>> guest mode.  Really, entering the guest is almost exactly like 
>> exiting to userspace.
>
> Hi Avi,
>
> I had a look at this and reworked the locking some, so we don't hold
> the slots_lock when entering the guest.
>
> How does this look? Xiantao any thoughts of whether it's unsafe to call
> kvm_vcpu_post_transition without holding that semaphore? I believe it
> should be fine.
>
> I am still seeing issues where the host can get a lock timeout when
> running large guests, but the situation seems to be better with this
> patch applied.
>

It looks fine, though I'm hardly qualified to review ia64 code.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.


  parent reply	other threads:[~2009-04-16  8:59 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-09 14:38 switching from KVM guest to the host .... TLBs not present? Jes Sorensen
2009-04-10 12:47 ` Zhang, Xiantao
2009-04-11 16:04 ` Avi Kivity
2009-04-14 11:43 ` Jes Sorensen
2009-04-16  8:43 ` Jes Sorensen
2009-04-16  8:59 ` Avi Kivity [this message]
2009-04-16  9:41 ` Zhang, Xiantao
2009-04-16  9:55 ` Avi Kivity
2009-04-16  9:57 ` Zhang, Xiantao

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