From: Alexander Duyck <alexander.duyck@gmail.com>
To: "Michael S. Tsirkin" <mst@redhat.com>, Avi Kivity <avi@scylladb.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: Having troubles binding an SR-IOV VF to uio_pci_generic on Amazon instance
Date: Thu, 1 Oct 2015 14:17:49 -0700 [thread overview]
Message-ID: <560DA2FD.1050507@gmail.com> (raw)
In-Reply-To: <20151001123335-mutt-send-email-mst@redhat.com>
On 10/01/2015 02:42 AM, Michael S. Tsirkin wrote:
> On Thu, Oct 01, 2015 at 12:22:46PM +0300, Avi Kivity wrote:
>> even when they are some users
>> prefer to avoid the performance penalty.
> I don't think there's a measureable penalty from passing through the
> IOMMU, as long as mappings are mostly static (i.e. iommu=pt). I sure
> never saw any numbers that show such.
It depends on the IOMMU. I believe Intel had a performance penalty on
all CPUs prior to Ivy Bridge. Since then things have improved to where
they are comparable to bare metal.
The graph on page 5 of
https://networkbuilders.intel.com/docs/Network_Builders_RA_vBRAS_Final.pdf
shows the penalty clear as day. Pretty much anything before Ivy Bridge
w/ small packets is slowed to a crawl with an IOMMU enabled.
- Alex
next prev parent reply other threads:[~2015-10-01 21:17 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-27 7:05 Having troubles binding an SR-IOV VF to uio_pci_generic on Amazon instance Vlad Zolotarov
2015-09-27 9:43 ` Michael S. Tsirkin
2015-09-27 10:50 ` Vladislav Zolotarov
2015-09-29 16:41 ` Vlad Zolotarov
2015-09-29 20:54 ` Michael S. Tsirkin
2015-09-29 21:46 ` Stephen Hemminger
2015-09-29 21:49 ` Michael S. Tsirkin
2015-09-30 10:37 ` Vlad Zolotarov
2015-09-30 10:58 ` Michael S. Tsirkin
2015-09-30 11:26 ` Vlad Zolotarov
2015-09-30 11:41 ` Michael S. Tsirkin
2015-09-30 11:53 ` Vlad Zolotarov
2015-09-30 12:03 ` Michael S. Tsirkin
2015-09-30 12:16 ` Vlad Zolotarov
2015-09-30 12:27 ` Michael S. Tsirkin
2015-09-30 12:50 ` Vlad Zolotarov
2015-09-30 15:26 ` Michael S. Tsirkin
2015-09-30 18:15 ` Vlad Zolotarov
2015-09-30 18:55 ` Michael S. Tsirkin
2015-09-30 19:06 ` Vlad Zolotarov
2015-09-30 19:10 ` Vlad Zolotarov
2015-09-30 19:11 ` Vlad Zolotarov
2015-09-30 19:39 ` Michael S. Tsirkin
2015-09-30 20:09 ` Vlad Zolotarov
2015-09-30 21:36 ` Stephen Hemminger
2015-09-30 21:53 ` Michael S. Tsirkin
2015-09-30 22:20 ` Vlad Zolotarov
2015-10-01 8:00 ` Vlad Zolotarov
2015-10-01 14:47 ` Stephen Hemminger
2015-10-01 15:03 ` Vlad Zolotarov
2015-09-30 13:05 ` Avi Kivity
2015-09-30 14:39 ` Michael S. Tsirkin
2015-09-30 14:53 ` Avi Kivity
2015-09-30 15:21 ` Michael S. Tsirkin
2015-09-30 15:36 ` Avi Kivity
2015-09-30 20:40 ` Michael S. Tsirkin
2015-09-30 21:00 ` Avi Kivity
2015-10-01 8:44 ` Michael S. Tsirkin
2015-10-01 8:46 ` Vlad Zolotarov
2015-10-01 8:52 ` Avi Kivity
2015-10-01 9:15 ` Michael S. Tsirkin
2015-10-01 9:22 ` Avi Kivity
2015-10-01 9:42 ` Michael S. Tsirkin
2015-10-01 9:53 ` Avi Kivity
2015-10-01 10:17 ` Michael S. Tsirkin
2015-10-01 10:24 ` Avi Kivity
2015-10-01 10:25 ` Avi Kivity
2015-10-01 10:44 ` Michael S. Tsirkin
2015-10-01 10:55 ` Avi Kivity
2015-10-01 21:17 ` Alexander Duyck [this message]
2015-10-02 13:50 ` Michael S. Tsirkin
2015-10-01 9:42 ` Vincent JARDIN
2015-10-01 9:43 ` Avi Kivity
2015-10-01 9:48 ` Vincent JARDIN
2015-10-01 9:54 ` Avi Kivity
2015-10-01 10:14 ` Michael S. Tsirkin
2015-10-01 10:23 ` Avi Kivity
2015-10-01 14:55 ` Stephen Hemminger
2015-10-01 15:49 ` Michael S. Tsirkin
2015-10-01 14:54 ` Stephen Hemminger
2015-10-01 16:02 ` Michael S. Tsirkin
2015-10-01 9:55 ` Michael S. Tsirkin
2015-10-01 9:59 ` Avi Kivity
2015-10-01 10:38 ` Michael S. Tsirkin
2015-10-01 10:50 ` Avi Kivity
2015-10-01 11:09 ` Michael S. Tsirkin
2015-10-01 11:20 ` Avi Kivity
2015-10-01 11:27 ` Michael S. Tsirkin
2015-10-01 11:32 ` Avi Kivity
2015-10-01 15:01 ` Stephen Hemminger
2015-10-01 15:08 ` Avi Kivity
2015-10-01 15:46 ` Michael S. Tsirkin
2015-10-01 15:11 ` Michael S. Tsirkin
2015-10-01 15:19 ` Avi Kivity
2015-10-01 15:40 ` Michael S. Tsirkin
2015-10-01 11:31 ` Michael S. Tsirkin
2015-10-01 11:34 ` Avi Kivity
2015-10-01 11:08 ` Bruce Richardson
2015-10-01 11:23 ` Michael S. Tsirkin
2015-10-01 12:07 ` Bruce Richardson
2015-10-01 13:14 ` Michael S. Tsirkin
2015-10-01 16:04 ` Michael S. Tsirkin
2015-10-01 21:02 ` Alexander Duyck
2015-10-02 14:00 ` Michael S. Tsirkin
2015-10-02 14:07 ` Bruce Richardson
2015-10-04 9:07 ` Michael S. Tsirkin
2015-10-02 15:56 ` Gleb Natapov
2015-10-02 16:57 ` Alexander Duyck
2015-10-01 9:15 ` Avi Kivity
2015-10-01 9:29 ` Michael S. Tsirkin
2015-10-01 9:38 ` Avi Kivity
2015-10-01 10:07 ` Michael S. Tsirkin
2015-10-01 10:11 ` Avi Kivity
2015-10-01 9:16 ` Michael S. Tsirkin
2015-09-30 17:28 ` Stephen Hemminger
2015-09-30 17:39 ` Michael S. Tsirkin
2015-09-30 17:43 ` Stephen Hemminger
2015-09-30 18:50 ` Michael S. Tsirkin
2015-09-30 20:00 ` Gleb Natapov
2015-09-30 20:36 ` Michael S. Tsirkin
2015-10-01 5:04 ` Gleb Natapov
2015-09-30 17:44 ` Gleb Natapov
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