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From: Avi Kivity <avi@redhat.com>
To: Gleb Natapov <gleb@redhat.com>
Cc: Jan Kiszka <jan.kiszka@web.de>, kvm-devel <kvm@vger.kernel.org>
Subject: Re: assign-dev: Purpose of interrupt_work
Date: Mon, 12 Oct 2009 11:40:59 +0200	[thread overview]
Message-ID: <4AD2F9AB.90607@redhat.com> (raw)
In-Reply-To: <20091012093831.GB16702@redhat.com>

On 10/12/2009 11:38 AM, Gleb Natapov wrote:
>
>> irqfd can work from interrupt context, so if we only use the
>> workqueue for the many-vcpu cases, we should be fine.
>>
>> I think we can do it cleanly, too: in ioapic code, if we're talking
>> to one vcpu, wake it immediately; otherwise schedule work to
>> continue in process context.  This was the common code can always
>> work in interrupt context and not worry about the work queue.
>>
>>      
> Even if we are talking to one cpu locking is still needed, so unless we
> make it spinlock we can't inject from irq context. If we change mutex to
> spinlock what is the point of work queue?
>    

Not to loop over 4096 vcpus with interrupts disabled, triggered by guest 
action.

-- 
error compiling committee.c: too many arguments to function


  reply	other threads:[~2009-10-12  9:41 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-12  7:03 assign-dev: Purpose of interrupt_work Jan Kiszka
2009-10-12  7:13 ` Gleb Natapov
2009-10-12  7:27   ` Jan Kiszka
2009-10-12  7:45     ` Gleb Natapov
2009-10-12  7:50       ` Jan Kiszka
2009-10-12  7:57         ` Gleb Natapov
2009-10-12  8:16           ` Jan Kiszka
2009-10-12  8:39             ` Gleb Natapov
2009-10-12  9:04               ` Jan Kiszka
2009-10-12  9:14                 ` Avi Kivity
2009-10-12  9:25                   ` Jan Kiszka
2009-10-12  9:30                     ` Avi Kivity
2009-10-12  9:38                       ` Gleb Natapov
2009-10-12  9:40                         ` Avi Kivity [this message]
2009-10-12  9:42                           ` Gleb Natapov
2009-10-12  9:14                 ` Gleb Natapov
2009-10-12  8:39         ` Avi Kivity
2009-10-12  9:05           ` Gleb Natapov
2009-10-12  9:07             ` Avi Kivity
2009-10-12  9:07           ` Jan Kiszka
2009-10-12  9:16             ` Avi Kivity
2009-10-12 17:36             ` Marcelo Tosatti
2009-10-12 20:44               ` Jan Kiszka

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