From: Peter Zijlstra <peterz@infradead.org>
To: Liu Ping Fan <kernelfans@gmail.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
qemu-devel@nongnu.org, Ingo Molnar <mingo@redhat.com>,
Avi Kivity <avi@redhat.com>,
Anthony Liguori <anthony@codemonkey.ws>
Subject: Re: [Qemu-devel] [PATCH 1/2] sched: add virt sched domain for the guest
Date: Wed, 23 May 2012 09:54:04 +0200 [thread overview]
Message-ID: <1337759644.9698.49.camel@twins> (raw)
In-Reply-To: <1337754751-9018-2-git-send-email-kernelfans@gmail.com>
On Wed, 2012-05-23 at 14:32 +0800, Liu Ping Fan wrote:
> From: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
>
> The guest's scheduler can not see the numa info on the host and
> this will result to the following scene:
> Supposing vcpu-a on nodeA, vcpu-b on nodeB, when load balance,
> the tasks' pull and push between these vcpus will cost more. But
> unfortunately, currently, the guest is just blind to this.
>
> This patch want to export the host numa info to the guest, and help
> guest to rebuild its sched domain based on host's info.
Hell no, we're not going to export sched domains, if kvm/qemu wants this
its all in sysfs.
The whole sched_domain stuff is a big enough pain as it is, exporting
this and making it a sodding API is the worst thing ever.
Whatever brainfart made you think this is needed anyway? sysfs contains
the host topology, qemu can already create whatever guest topology you
want (see the -smp and -numa arguments), so what gives?
next prev parent reply other threads:[~2012-05-23 7:54 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-23 6:32 [Qemu-devel] [RFC] kvm: export host NUMA info to guest's scheduler Liu Ping Fan
2012-05-23 6:32 ` [Qemu-devel] [PATCH 1/2] sched: add virt sched domain for the guest Liu Ping Fan
2012-05-23 7:54 ` Peter Zijlstra [this message]
2012-05-23 8:10 ` Liu ping fan
2012-05-23 8:23 ` Peter Zijlstra
2012-05-23 8:34 ` Liu ping fan
2012-05-23 8:48 ` Peter Zijlstra
2012-05-23 9:58 ` Liu ping fan
2012-05-23 10:14 ` Peter Zijlstra
2012-05-23 15:23 ` Dave Hansen
2012-05-23 15:52 ` Peter Zijlstra
2012-05-23 6:32 ` [Qemu-devel] [PATCH 2/2] sched: add virt domain device's driver Liu Ping Fan
2012-05-23 6:32 ` [Qemu-devel] [PATCH] kvm: collect vcpus' numa info for guest's scheduler Liu Ping Fan
2012-05-23 6:32 ` [Qemu-devel] [PATCH] Qemu: add virt sched domain device Liu Ping Fan
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=1337759644.9698.49.camel@twins \
--to=peterz@infradead.org \
--cc=anthony@codemonkey.ws \
--cc=avi@redhat.com \
--cc=kernelfans@gmail.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--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).