From: Stephen Hemminger <stephen@networkplumber.org>
To: edgar helmut <helmut.edgar100@gmail.com>
Cc: "Hu, Xuekun" <xuekun.hu@intel.com>,
"Wiles, Keith" <keith.wiles@intel.com>,
"users@dpdk.org" <users@dpdk.org>
Subject: Re: [dpdk-users] Dpdk poor performance on virtual machine
Date: Thu, 15 Dec 2016 11:14:27 -0800 [thread overview]
Message-ID: <20161215111427.3e9e72a2@xeon-e3> (raw)
In-Reply-To: <CABc_bMBa76QbrZ2Lg4Aeii8-3R-_uN8VtCAK35SMBDDT7E1LcQ@mail.gmail.com>
On Thu, 15 Dec 2016 19:29:54 +0200
edgar helmut <helmut.edgar100@gmail.com> wrote:
> Stephen, this is not the case, it relies on using the transparent hugepages
> which looks like 2M hugepages size.
> Why should be a problem to back 1G pages of the guest to 2M pages at the
> host?
> the transparent hugepages makes the deployment much more flexible.
The IOMMU has a cache (like TLB) which has a limited number of slots.
If using 2M pages then the IOMMU cache misses will cause a performance drop
just like CPU cache misses. I think Intel had some slides back at IDF 2012
that showed the impact.
next prev parent reply other threads:[~2016-12-15 19:14 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CABc_bMBYNa7jdhqu2SNZkwtoJskCwQWGOZrB71RYzBZx5-OTfw@mail.gmail.com>
[not found] ` <CABc_bMBMxhbkGSg82tw7CKLw7AiccEESLAJaHGA6PAaYAPCmTg@mail.gmail.com>
[not found] ` <CABc_bMB2vnXEpacfeiWiC5X-x8iuB7jO6fR67n5jj67Pspcf2g@mail.gmail.com>
[not found] ` <CABc_bMB7C2zRjEkFbtAyk7buaP=QWwxCSwz=60AVJT_rjoPZTQ@mail.gmail.com>
[not found] ` <CABc_bMDgU62=i5uE52d12VGd8wUzqHq9siOjYKSh8v811TYpug@mail.gmail.com>
[not found] ` <CABc_bMCn9LivEn_PJCh+dQy7pPypLdmE+eZFQZtzphsHEgr08g@mail.gmail.com>
[not found] ` <CABc_bMADQ3PaZz5ovLmGu=3_w2pTO3c6BvNPM6-BUzJ5BXjxLQ@mail.gmail.com>
[not found] ` <CABc_bMBJ+NZLuo___qw_cBB=z=5nzgVx6rMd15nMiSYf_q3WoQ@mail.gmail.com>
[not found] ` <CABc_bMC6qP3K-kqVQORc9XKfbcXX63UfN=AdZ+sksHUN+Bx5kw@mail.gmail.com>
[not found] ` <CABc_bMDowcZKMrKc8omf-JqpUW=uPn-fq8sfLYk=AktbH9-aNw@mail.gmail.com>
[not found] ` <CABc_bMACisgaHBZedG05ZzJ3wzmudgBeTHdRr93M3-QOGKDKNw@mail.gmail.com>
[not found] ` <CABc_bMCTRDYy+9ZO6py+KupRStR=Rc4md+J0NhPcyTqaZhKxTA@mail.gmail.com>
[not found] ` <CABc_bMAu8BkZXzBSZLWNs=R6AJgMAw9WrTki=cEzMzjC7Z8LAQ@mail.gmail.com>
[not found] ` <CABc_bMDtzYE4NvhAT8nqi3qZbzV4WauzJLW-tcY_Wi5i88F7yQ@mail.gmail.com>
[not found] ` <CABc_bMAr0EjgH4f7UT-oi353FBqYwxt-UgfP6candcP=jkuyLg@mail.gmail.com>
[not found] ` <CABc_bMCyJ4o94T=VRWPjfyhXP1T3uDmeYVsu+0OrXi1AqUkLrg@mail.gmail.com>
[not found] ` <CABc_bMBK=AQ31=mQX0f7HMXs6REqj_bkqQ9KPD96vbtoKKHWCw@mail.gmail.com>
[not found] ` <CABc_bMA8z6XBEtnxwPE_LDpngx_DYRathn17KqFxNx2V5DFbng@mail.gmail.com>
[not found] ` <CABc_bMBwFAL5rc5goMP9pt+2z=TOM=VNfp76AznZ3jend9aS_Q@mail.gmail.com>
[not found] ` <CABc_bMBr1c_Evd5zxB89SinNFVMUGHFTBDoLusVHdMySBCyaBA@mail.gmail.com>
[not found] ` <CABc_bMChD5hpWmj1zhvZ5tocsxDCFH0QdE34TKWXsdo_danH-Q@mail.gmail.com>
[not found] ` <CABc_bMCqu-4V4gn=JPqO491BF6Cnjj=4SaAey9qyTQcha134yw@mail.gmail.com>
2016-12-15 7:20 ` edgar helmut
2016-12-15 12:54 ` Wiles, Keith
2016-12-15 13:32 ` edgar helmut
2016-12-15 14:33 ` Hu, Xuekun
2016-12-15 17:17 ` Stephen Hemminger
2016-12-15 17:29 ` edgar helmut
2016-12-15 19:14 ` Stephen Hemminger [this message]
2016-12-15 19:29 ` Jes Nielsen
2016-12-15 17:24 ` edgar helmut
2016-12-16 1:14 ` Hu, Xuekun
2016-12-17 12:56 ` edgar helmut
2016-12-23 19:22 ` edgar helmut
2016-12-24 7:06 ` Hu, Xuekun
2016-12-24 8:06 ` edgar helmut
2016-12-24 15:52 ` edgar helmut
2016-12-26 0:52 ` Hu, Xuekun
2016-12-27 15:52 ` edgar helmut
2016-12-27 15:59 ` edgar helmut
2016-12-27 18:52 ` Stephen Hemminger
2016-12-28 8:09 ` edgar helmut
2017-01-04 6:44 ` edgar helmut
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=20161215111427.3e9e72a2@xeon-e3 \
--to=stephen@networkplumber.org \
--cc=helmut.edgar100@gmail.com \
--cc=keith.wiles@intel.com \
--cc=users@dpdk.org \
--cc=xuekun.hu@intel.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).