From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jan Kiszka <jan.kiszka@web.de>
Subject: Re: assign-dev: Purpose of interrupt_work
Date: Mon, 12 Oct 2009 09:27:19 +0200
Message-ID: <4AD2DA57.6030006@web.de>
References: <4AD2D4B6.7030203@web.de> <20091012071310.GT16702@redhat.com>
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Cc: Avi Kivity <avi@redhat.com>, kvm-devel <kvm@vger.kernel.org>
To: Gleb Natapov <gleb@redhat.com>
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Gleb Natapov wrote:
> On Mon, Oct 12, 2009 at 09:03:18AM +0200, Jan Kiszka wrote:
>> Hi,
>>
>> I was starring at the IRQ delivery path of assigned devices for a whil=
e,
>> wondering why we have a work queue there. Now, after looking at some
>> prehistoric versions, I think the reason is that there once was a mute=
x
>> involved while we now use RCU. Am I right that we could actually drop
>> this indirection today?
>>
> ioapic/pic path still has mutex. If MSIX is used (like it should) we ca=
n
> drop work queue.

I see. Wouldn't it be feasible to convert the fast paths of [io]apic to
spinlocks?

Jan


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