From: Avi Kivity <avi@redhat.com>
To: Gregory Haskins <ghaskins@novell.com>
Cc: Anthony Liguori <anthony@codemonkey.ws>,
Andi Kleen <andi@firstfloor.org>,
linux-kernel@vger.kernel.org, agraf@suse.de,
pmullaney@novell.com, pmorreale@novell.com,
rusty@rustcorp.com.au, netdev@vger.kernel.org,
kvm@vger.kernel.org
Subject: Re: [RFC PATCH 00/17] virtual-bus
Date: Thu, 02 Apr 2009 17:32:01 +0300 [thread overview]
Message-ID: <49D4CC61.6010105@redhat.com> (raw)
In-Reply-To: <49D4CAA7.3020004@novell.com>
Gregory Haskins wrote:
>> If you have a request-response workload with the wire idle and latency
>> critical, then there's no problem having an exit per packet because
>> (a) there aren't that many packets and (b) the guest isn't doing any
>> batching, so guest overhead will swamp the hypervisor overhead.
>>
> Right, so the trick is to use an algorithm that adapts here. Batching
> solves the first case, but not the second. The bidir napi thing solves
> both, but it does assume you have ample host processing power to run the
> algorithm concurrently. This may or may not be suitable to all
> applications, I admit.
>
The alternative is to get a notification from the stack that the packet
is done processing. Either an skb destructor in the kernel, or my new
API that everyone is not rushing out to implement.
>>> Right now its way way way worse than 2us. In fact, at my last reading
>>> this was more like 3060us (3125-65). So shorten that 3125 to 67 (while
>>> maintaining line-rate) and I will be impressed. Heck, shorten it to
>>> 80us and I will be impressed.
>>>
>>>
>> The 3060us thing is a timer, not cpu time.
>>
> Agreed, but its still "state of the art" from an observer perspective.
> The reason "why", though easily explainable, is inconsequential to most
> people. FWIW, I have seen virtio-net do a much more respectable 350us
> on an older version, so I know there is plenty of room for improvement.
>
All I want is the notification, and the timer is headed into the nearest
landfill.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2009-04-02 14:32 UTC|newest]
Thread overview: 164+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-31 18:42 [RFC PATCH 00/17] virtual-bus Gregory Haskins
2009-03-31 18:42 ` [RFC PATCH 01/17] shm-signal: shared-memory signals Gregory Haskins
2009-03-31 20:44 ` Avi Kivity
2009-03-31 20:58 ` Gregory Haskins
2009-03-31 21:05 ` Avi Kivity
2009-04-01 12:12 ` Gregory Haskins
2009-04-01 12:24 ` Avi Kivity
2009-04-01 13:57 ` Gregory Haskins
2009-03-31 18:42 ` [RFC PATCH 02/17] vbus: add virtual-bus definitions Gregory Haskins
2009-04-02 16:06 ` Ben Hutchings
2009-04-02 18:13 ` Gregory Haskins
2009-03-31 18:43 ` [RFC PATCH 03/17] vbus: add connection-client helper infrastructure Gregory Haskins
2009-03-31 18:43 ` [RFC PATCH 04/17] vbus: add bus-registration notifiers Gregory Haskins
2009-03-31 18:43 ` [RFC PATCH 05/17] vbus: add a "vbus-proxy" bus model for vbus_driver objects Gregory Haskins
2009-03-31 18:43 ` [RFC PATCH 06/17] ioq: Add basic definitions for a shared-memory, lockless queue Gregory Haskins
2009-03-31 18:43 ` [RFC PATCH 07/17] ioq: add vbus helpers Gregory Haskins
2009-03-31 18:43 ` [RFC PATCH 08/17] venet: add the ABI definitions for an 802.x packet interface Gregory Haskins
2009-03-31 18:43 ` [RFC PATCH 09/17] net: Add vbus_enet driver Gregory Haskins
2009-03-31 20:39 ` Stephen Hemminger
2009-04-02 11:43 ` Gregory Haskins
2009-03-31 18:43 ` [RFC PATCH 10/17] venet-tap: Adds a "venet" compatible "tap" device to VBUS Gregory Haskins
2009-03-31 18:43 ` [RFC PATCH 11/17] venet: add scatter-gather support Gregory Haskins
2009-03-31 18:43 ` [RFC PATCH 12/17] venettap: " Gregory Haskins
2009-03-31 18:43 ` [RFC PATCH 13/17] x86: allow the irq->vector translation to be determined outside of ioapic Gregory Haskins
2009-03-31 19:16 ` Alan Cox
2009-03-31 20:02 ` Gregory Haskins
2009-03-31 18:44 ` [RFC PATCH 14/17] kvm: add a reset capability Gregory Haskins
2009-03-31 19:22 ` Avi Kivity
2009-03-31 20:02 ` Gregory Haskins
2009-03-31 20:18 ` Avi Kivity
2009-03-31 20:37 ` Gregory Haskins
2009-03-31 18:44 ` [RFC PATCH 15/17] kvm: add dynamic IRQ support Gregory Haskins
2009-03-31 19:20 ` Avi Kivity
2009-03-31 19:39 ` Gregory Haskins
2009-03-31 20:13 ` Avi Kivity
2009-03-31 20:32 ` Gregory Haskins
2009-03-31 20:59 ` Avi Kivity
2009-03-31 18:44 ` [RFC PATCH 16/17] kvm: Add VBUS support to the host Gregory Haskins
2009-03-31 18:44 ` [RFC PATCH 17/17] kvm: Add guest-side support for VBUS Gregory Haskins
2009-03-31 20:18 ` [RFC PATCH 00/17] virtual-bus Andi Kleen
2009-04-01 12:03 ` Gregory Haskins
2009-04-01 13:23 ` Andi Kleen
2009-04-01 14:19 ` Gregory Haskins
2009-04-01 14:42 ` Gregory Haskins
2009-04-01 17:01 ` Andi Kleen
2009-04-01 18:45 ` Anthony Liguori
2009-04-01 20:40 ` Chris Wright
2009-04-01 21:11 ` Gregory Haskins
2009-04-01 21:28 ` Chris Wright
2009-04-01 22:10 ` Gregory Haskins
2009-04-02 6:00 ` Chris Wright
2009-04-02 3:11 ` Herbert Xu
2009-04-01 21:09 ` Gregory Haskins
2009-04-02 0:29 ` Anthony Liguori
2009-04-02 3:11 ` Gregory Haskins
2009-04-02 6:51 ` Avi Kivity
2009-04-02 8:52 ` Herbert Xu
2009-04-02 9:02 ` Avi Kivity
2009-04-02 9:16 ` Herbert Xu
2009-04-02 9:27 ` Avi Kivity
2009-04-02 9:29 ` Herbert Xu
2009-04-02 9:33 ` Herbert Xu
2009-04-02 9:38 ` Avi Kivity
2009-04-02 9:41 ` Herbert Xu
2009-04-02 9:43 ` Avi Kivity
2009-04-02 9:44 ` Herbert Xu
2009-04-02 11:06 ` Gregory Haskins
2009-04-02 11:59 ` Avi Kivity
2009-04-02 12:30 ` Gregory Haskins
2009-04-02 12:43 ` Avi Kivity
2009-04-02 13:03 ` Gregory Haskins
2009-04-02 12:13 ` Rusty Russell
2009-04-02 12:50 ` Gregory Haskins
2009-04-02 12:52 ` Gregory Haskins
2009-04-02 13:07 ` Avi Kivity
2009-04-02 13:22 ` Gregory Haskins
2009-04-02 13:27 ` Avi Kivity
2009-04-02 14:05 ` Gregory Haskins
2009-04-02 14:50 ` Herbert Xu
2009-04-02 15:00 ` Avi Kivity
2009-04-02 15:40 ` Herbert Xu
2009-04-02 15:57 ` Avi Kivity
2009-04-02 16:09 ` Herbert Xu
2009-04-02 16:54 ` Avi Kivity
2009-04-02 17:06 ` Herbert Xu
2009-04-02 17:17 ` Herbert Xu
2009-04-03 12:25 ` Avi Kivity
2009-04-02 15:10 ` Michael S. Tsirkin
2009-04-03 4:43 ` Jeremy Fitzhardinge
2009-04-02 10:55 ` Gregory Haskins
2009-04-02 11:48 ` Avi Kivity
2009-04-03 10:58 ` Gerd Hoffmann
2009-04-03 11:03 ` Avi Kivity
2009-04-03 11:12 ` Herbert Xu
2009-04-03 11:46 ` Avi Kivity
2009-04-03 11:48 ` Herbert Xu
2009-04-03 11:54 ` Avi Kivity
2009-04-03 11:55 ` Herbert Xu
2009-04-03 12:02 ` Avi Kivity
2009-04-03 13:05 ` Herbert Xu
2009-04-03 11:18 ` Andi Kleen
2009-04-03 11:34 ` Herbert Xu
2009-04-03 11:46 ` Avi Kivity
2009-04-03 11:28 ` Gregory Haskins
2009-04-02 10:46 ` Gregory Haskins
2009-04-02 11:43 ` Avi Kivity
2009-04-02 12:22 ` Gregory Haskins
2009-04-02 12:42 ` Avi Kivity
2009-04-02 12:54 ` Gregory Haskins
2009-04-02 13:08 ` Avi Kivity
2009-04-02 13:36 ` Gregory Haskins
2009-04-02 13:45 ` Avi Kivity
2009-04-02 14:24 ` Gregory Haskins
2009-04-02 14:32 ` Avi Kivity [this message]
2009-04-02 14:41 ` Avi Kivity
2009-04-02 14:49 ` Anthony Liguori
2009-04-02 16:09 ` Anthony Liguori
2009-04-02 16:19 ` Avi Kivity
2009-04-02 18:18 ` Anthony Liguori
2009-04-03 1:11 ` Herbert Xu
2009-04-20 18:02 ` [kvm] " Alex Williamson
2009-04-20 18:02 ` Alex Williamson
2009-04-03 12:03 ` Gregory Haskins
2009-04-03 12:15 ` Avi Kivity
2009-04-03 13:13 ` Gregory Haskins
2009-04-03 13:37 ` Avi Kivity
2009-04-03 13:37 ` Avi Kivity
2009-04-03 16:28 ` Gregory Haskins
2009-04-03 16:28 ` Gregory Haskins
2009-04-05 10:00 ` Avi Kivity
2009-04-05 10:00 ` Avi Kivity
2009-04-02 3:09 ` Herbert Xu
2009-04-02 6:46 ` Avi Kivity
2009-04-02 8:54 ` Herbert Xu
2009-04-02 9:03 ` Avi Kivity
2009-04-02 9:05 ` Herbert Xu
2009-04-01 20:29 ` Gregory Haskins
2009-04-01 22:23 ` Andi Kleen
2009-04-01 23:05 ` Gregory Haskins
2009-04-01 6:08 ` Rusty Russell
2009-04-01 11:35 ` Gregory Haskins
2009-04-02 1:24 ` Rusty Russell
2009-04-02 2:27 ` Gregory Haskins
2009-04-01 16:10 ` Anthony Liguori
2009-04-05 3:44 ` Rusty Russell
2009-04-05 8:06 ` Avi Kivity
2009-04-05 14:13 ` Anthony Liguori
2009-04-05 16:10 ` Avi Kivity
2009-04-05 16:45 ` Anthony Liguori
2009-04-02 3:15 ` Herbert Xu
[not found] <49D469D2020000A100045FA1@lucius.provo.novell.com>
2009-04-02 14:14 ` Patrick Mullaney
2009-04-02 14:27 ` Avi Kivity
2009-04-02 15:31 ` Gregory Haskins
2009-04-02 15:49 ` Avi Kivity
2009-04-02 16:06 ` Herbert Xu
2009-04-02 16:51 ` Avi Kivity
2009-04-02 17:44 ` Gregory Haskins
2009-04-03 11:43 ` Avi Kivity
2009-04-03 14:58 ` Gregory Haskins
2009-04-03 15:37 ` Avi Kivity
2009-04-03 18:19 ` Gregory Haskins
2009-04-05 10:50 ` Avi Kivity
2009-04-03 17:09 ` Chris Wright
2009-04-03 18:32 ` Gregory Haskins
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=49D4CC61.6010105@redhat.com \
--to=avi@redhat.com \
--cc=agraf@suse.de \
--cc=andi@firstfloor.org \
--cc=anthony@codemonkey.ws \
--cc=ghaskins@novell.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pmorreale@novell.com \
--cc=pmullaney@novell.com \
--cc=rusty@rustcorp.com.au \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.