From: Anthony Liguori <anthony@codemonkey.ws>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Asias He <asias@redhat.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH RESEND 5/5] vhost-blk: Add vhost-blk support
Date: Fri, 20 Jul 2012 15:56:19 -0500 [thread overview]
Message-ID: <87obnaup70.fsf@codemonkey.ws> (raw)
In-Reply-To: <20120719130957.GD9303@redhat.com>
"Michael S. Tsirkin" <mst@redhat.com> writes:
> On Thu, Jul 19, 2012 at 08:05:42AM -0500, Anthony Liguori wrote:
>> Of course, the million dollar question is why would using AIO in the
>> kernel be faster than using AIO in userspace?
>
> Actually for me a more important question is how does it compare
> with virtio-blk dataplane?
I'm not even asking for a benchmark comparision. It's the same API
being called from a kernel thread vs. a userspace thread. Why would
there be a 60% performance difference between the two? That doesn't
make any sense.
There's got to be a better justification for putting this in the kernel
than just that we can.
I completely understand why Christoph's suggestion of submitting BIOs
directly would be faster. There's no way to do that in userspace.
Regards,
Anthony Liguori
>
> --
> MST
next prev parent reply other threads:[~2012-07-20 20:56 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-13 8:55 [PATCH RESEND 0/5] Add vhost-blk support Asias He
2012-07-13 8:55 ` Asias He
2012-07-13 8:55 ` [PATCH RESEND 1/5] aio: Export symbols and struct kiocb_batch for in kernel aio usage Asias He
2012-07-13 8:55 ` Asias He
2012-07-13 8:55 ` Asias He
2012-07-13 8:55 ` [PATCH RESEND 2/5] eventfd: Export symbol eventfd_file_create() Asias He
2012-07-13 8:55 ` Asias He
2012-07-13 8:55 ` [PATCH RESEND 3/5] vhost: Make vhost a separate module Asias He
2012-07-13 8:55 ` Asias He
2012-07-13 8:55 ` [PATCH RESEND 4/5] vhost-net: Use VHOST_NET_FEATURES for vhost-net Asias He
2012-07-13 8:55 ` Asias He
2012-07-13 8:55 ` [PATCH RESEND 5/5] vhost-blk: Add vhost-blk support Asias He
2012-07-13 8:55 ` Asias He
2012-07-17 19:10 ` Jeff Moyer
2012-07-17 19:10 ` Jeff Moyer
2012-07-18 1:22 ` Asias He
2012-07-18 1:22 ` Asias He
2012-07-18 14:31 ` Jeff Moyer
2012-07-18 14:45 ` Asias He
2012-07-18 14:45 ` Asias He
2012-07-18 14:31 ` Jeff Moyer
2012-07-19 13:05 ` Anthony Liguori
2012-07-19 13:05 ` Anthony Liguori
2012-07-19 13:09 ` Michael S. Tsirkin
2012-07-19 13:09 ` Michael S. Tsirkin
2012-07-19 13:09 ` Michael S. Tsirkin
2012-07-19 13:09 ` Michael S. Tsirkin
2012-07-20 10:31 ` Stefan Hajnoczi
2012-07-20 10:31 ` Stefan Hajnoczi
2012-07-20 20:56 ` Anthony Liguori
2012-07-20 20:56 ` Anthony Liguori [this message]
2012-07-21 1:07 ` Asias He
2012-07-21 1:07 ` Asias He
2012-07-14 7:49 ` [PATCH RESEND 0/5] " Christoph Hellwig
2012-07-14 7:49 ` Christoph Hellwig
2012-07-14 7:49 ` Christoph Hellwig
2012-07-16 9:05 ` Asias He
2012-07-16 9:05 ` Asias He
2012-07-16 9:05 ` Asias He
2012-07-17 15:09 ` Michael S. Tsirkin
2012-07-17 15:09 ` Michael S. Tsirkin
2012-07-17 15:09 ` Michael S. Tsirkin
2012-07-18 2:09 ` Asias He
2012-07-18 2:09 ` Asias He
2012-07-18 2:09 ` Asias He
2012-07-18 11:42 ` Stefan Hajnoczi
2012-07-18 11:42 ` Stefan Hajnoczi
2012-07-20 19:30 ` Michael S. Tsirkin
2012-07-20 19:30 ` Michael S. Tsirkin
2012-07-20 19:30 ` Michael S. Tsirkin
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