From: Pekka Enberg <penberg@kernel.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Asias He <asias.hejun@gmail.com>,
Cyrill Gorcunov <gorcunov@gmail.com>,
Sasha Levin <levinsasha928@gmail.com>,
Prasad Joshi <prasadjoshi124@gmail.com>,
kvm@vger.kernel.org
Subject: Re: [PATCH 3/3] kvm tools: Make virtio-blk kvm__irq_line thread safe
Date: Fri, 29 Apr 2011 09:55:13 +0300 [thread overview]
Message-ID: <BANLkTik_wXBA+4X-BRE_H-yUEkbSTcOt5A@mail.gmail.com> (raw)
In-Reply-To: <20110429064433.GB13893@elte.hu>
On Fri, Apr 29, 2011 at 9:44 AM, Ingo Molnar <mingo@elte.hu> wrote:
> Hm, this looks a bit strange (the mutex here protects only a kernel call - that
> cannot be right) and there's no explanation why it's needed. Why do
> VIRTIO_BLK_IRQ (== KVM_IRQ_LINE ioctl()) calls have to be covered by the mutex?
>
> A short blurb about expected behavior on SMP and locking rules at the top of
> virtio-blk.c would be nice.
Yes, looks strange. Asias, did you see some bad behavior that this
fixes? The per-device mutexes are there to protect device state. The
assumption here is that KVM handles KVM_IRQ_LINE ioctl() serialization
by titself.
next prev parent reply other threads:[~2011-04-29 6:55 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-29 6:36 [PATCH 1/3] kvm tools: Make virtio-net kvm__irq_line thread safe Asias He
2011-04-29 6:36 ` [PATCH 2/3] kvm tools: Make virtio-console " Asias He
2011-04-29 6:44 ` Ingo Molnar
2011-04-29 6:36 ` [PATCH 3/3] kvm tools: Make virtio-blk " Asias He
2011-04-29 6:44 ` Ingo Molnar
2011-04-29 6:55 ` Pekka Enberg [this message]
2011-04-29 7:26 ` Asias He
2011-04-29 7:55 ` Pekka Enberg
2011-04-29 8:29 ` Sasha Levin
2011-04-29 6:46 ` [PATCH 1/3] kvm tools: Make virtio-net " Ingo Molnar
2011-04-29 6:52 ` Pekka Enberg
2011-04-29 7:13 ` Asias He
2011-04-29 7:15 ` Pekka Enberg
2011-04-29 7:38 ` Asias He
2011-04-29 7:45 ` Ingo Molnar
2011-04-29 7:53 ` Sasha Levin
2011-04-29 10:02 ` Cyrill Gorcunov
2011-04-29 10:37 ` Pekka Enberg
2011-04-29 10:47 ` Cyrill Gorcunov
2011-04-29 10:22 ` Ingo Molnar
2011-04-29 16:52 ` Sasha Levin
2011-04-29 20:39 ` Ingo Molnar
2011-04-29 7:30 ` Ingo Molnar
2011-04-29 7:47 ` Asias He
2011-04-29 10:32 ` Ingo Molnar
2011-04-29 10:42 ` Pekka Enberg
2011-04-29 17:43 ` Pekka Enberg
2011-04-29 19:59 ` Ingo Molnar
2011-04-30 7:44 ` Pekka Enberg
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