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Date: Tue, 26 Nov 2013 14:13:25 +0100
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [RFC] create a single workqueue for each vm to
 update vm irq routing table
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To: Gleb Natapov <gleb@redhat.com>
Cc: "Huangweidong (C)" <weidong.huang@huawei.com>, KVM <kvm@vger.kernel.org>, "Michael S. Tsirkin" <mst@redhat.com>, "Jinxin (F)" <jinxin712@huawei.com>, "Zhanghaoyu (A)" <haoyu.zhang@huawei.com>, Luonengjun <luonengjun@huawei.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, Zanghongyong <zanghongyong@huawei.com>

Il 26/11/2013 13:56, Gleb Natapov ha scritto:
> > I don't think a workqueue is even needed.  You just need to use call_rcu
> > to free "old" after releasing kvm->irq_lock.
> > 
> > What do you think?
> 
> It should be rate limited somehow. Since it guest triggarable guest may cause
> host to allocate a lot of memory this way.

True, though if I understand Zhanghaoyu's proposal a workqueue would be
even worse.

Paolo