From: Udo Lembke <ulembke@polarzone.de>
To: Avi Kivity <avi@redhat.com>
Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org
Subject: [Qemu-devel] Re: [PATCH 10/12] kvm: enable smp > 1
Date: Wed, 19 May 2010 22:02:50 +0200 [thread overview]
Message-ID: <4BF443EA.3020405@polarzone.de> (raw)
In-Reply-To: <4BF41025.9020107@redhat.com>
Avi Kivity schrieb:
> On 05/19/2010 12:57 PM, Udo Lembke wrote:
>> Jan Kiszka schrieb:
>>> ...
>>> --enable-io-thread?
>>>
>>> If you had it disabled, it would also answer my question if -smp works
>>> without problems without that feature.
>>>
>>> Jan
>>>
>> Hi,
>> i have a dumb question: what is the "--enable-io-thread"? Is this a
>> kvm-switch?
>
> It's a ./configure switch for upstream qemu (don't use with qemu-kvm
> yet).
>
>> My kvm 0.12.4 don't accept this switch. I'm know only "threads=n" as
>> smp-parameter and "aio=threads" as drive-parameter.
>>
>> Because i look for a solution for a better io-performance of
>> windows-guest with more than one cpu...
>
> Unrelated, what are your smp issues?
>
If i use one cpu i got a good io-performance:
e.g. over 500MB/s at the profile "install" of the io-benchmark h2benchw.exe.
( aio=threads | SAS-Raid-0 | ftp://ftp.heise.de/pub/ct/ctsi/h2benchw.zip
| hwbenchw.exe -p -w iotest 0)
The same test but with two cpus gives results between 27 and 298 MB/s!
Also in real life it's noticeable not only with an benchmark. I use a
win-vm with two cpu for postscript-ripping and have a performance drop
due to the bad io.
Udo
next prev parent reply other threads:[~2010-05-19 20:03 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-12 21:24 [Qemu-devel] [PATCH 00/12] [PULL] qemu-kvm.git uq/master queue Marcelo Tosatti
2010-05-12 21:24 ` [Qemu-devel] [PATCH 01/12] Fix -mem-path with hugetlbfs Marcelo Tosatti
2010-05-12 21:24 ` [Qemu-devel] [PATCH 02/12] kvm: set cpu_single_env around KVM_RUN ioctl Marcelo Tosatti
2010-05-12 21:24 ` [Qemu-devel] [PATCH 03/12] make SIG_IPI to tcg vcpu thread reliable Marcelo Tosatti
2010-05-12 21:24 ` [Qemu-devel] [PATCH 04/12] standardize on qemu_cpu_kick for signalling cpu thread(s) Marcelo Tosatti
2010-05-12 21:24 ` [Qemu-devel] [PATCH 05/12] port qemu-kvm's on_vcpu code Marcelo Tosatti
2010-05-12 21:25 ` [Qemu-devel] [PATCH 06/12] kvm: synchronize state from cpu context Marcelo Tosatti
2010-05-12 21:25 ` [Qemu-devel] [PATCH 07/12] add cpu_is_stopped helper Marcelo Tosatti
2010-05-12 21:25 ` [Qemu-devel] [PATCH 08/12] move stop/stopped CPU_COMMON fields after area zeroed by reset Marcelo Tosatti
2010-05-12 21:25 ` [Qemu-devel] [PATCH 09/12] kvm: validate context for kvm cpu get/put operations Marcelo Tosatti
2010-05-12 21:25 ` [Qemu-devel] [PATCH 10/12] kvm: enable smp > 1 Marcelo Tosatti
2010-05-14 14:06 ` [Qemu-devel] " Alexander Graf
2010-05-14 15:48 ` Avi Kivity
2010-05-14 15:49 ` Alexander Graf
2010-05-14 15:54 ` Jan Kiszka
2010-05-14 15:58 ` Alexander Graf
2010-05-19 9:57 ` Udo Lembke
2010-05-19 16:21 ` Avi Kivity
2010-05-19 20:02 ` Udo Lembke [this message]
2010-05-20 6:12 ` Avi Kivity
2010-05-20 7:01 ` Udo Lembke
2010-05-12 21:25 ` [Qemu-devel] [PATCH 11/12] Do not stop VM if emulation failed in userspace Marcelo Tosatti
2010-05-12 21:25 ` [Qemu-devel] [PATCH 12/12] kvm: fix 80000001.EDX supported bit filtering Marcelo Tosatti
2010-05-17 18:10 ` [Qemu-devel] [PATCH 00/12] [PULL] qemu-kvm.git uq/master queue Anthony Liguori
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=4BF443EA.3020405@polarzone.de \
--to=ulembke@polarzone.de \
--cc=avi@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=qemu-devel@nongnu.org \
/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).