linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Joerg Roedel <joro@8bytes.org>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Avi Kivity <avi@redhat.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Ingo Molnar <mingo@elte.hu>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Subject: Re: [PATCH v1 0/5] KVM in-guest performance monitoring
Date: Thu, 12 May 2011 15:43:40 +0200	[thread overview]
Message-ID: <20110512134339.GH8707@8bytes.org> (raw)
In-Reply-To: <4DCBDF5B.6000101@siemens.com>

On Thu, May 12, 2011 at 03:23:39PM +0200, Jan Kiszka wrote:
> On 2011-05-12 15:11, Joerg Roedel wrote:

> > Seriously, I think such decisions should be technical only and not
> > political like that. The losers of such political decisions are always
> > the users because they don't get useful features that are technical
> > possible.
> 
> Paravirt remains a workaround, useful until hardware provides a solution
> for all guests, and that often in an even more efficient way (like for
> MMU virtualization).

Fully agreed. And todays x86 CPUs lack proper support for virtualizing
the PMU. That will hopefully change but users want the feature today.

> We do not need to block a PV-PMU for Linux guests (or other OSes that
> want to adopt to it), but that will not be a solution for the problem,
> that's my point. A PV-PMU may even be useful to demonstrate usefulness
> of a virtual PMU the CPU vendors (if they aren't aware of this yet).

Right, if users actually use the virtual PMU this probably increases the
priority for proper hardware support.

	Joerg


  reply	other threads:[~2011-05-12 13:43 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-11 15:55 [PATCH v1 0/5] KVM in-guest performance monitoring Avi Kivity
2011-05-11 15:55 ` [PATCH v1 1/5] perf: add context parameter to perf_event overflow handler Avi Kivity
2011-06-03 14:41   ` Peter Zijlstra
2011-06-05  8:07     ` Avi Kivity
2011-05-11 15:55 ` [PATCH v1 2/5] x86, perf: add constraints for architectural PMU v1 Avi Kivity
2011-05-11 15:55 ` [PATCH v1 3/5] perf: export perf_event_refresh() to modules Avi Kivity
2011-05-11 15:55 ` [PATCH v1 4/5] KVM: Expose kvm_lapic_local_deliver() Avi Kivity
2011-05-11 15:55 ` [PATCH v1 5/5] KVM: Expose a version 1 architectural PMU to guests Avi Kivity
2011-05-17 19:41   ` Ingo Molnar
2011-05-18  9:03     ` Avi Kivity
2011-05-18 11:07       ` Ingo Molnar
2011-05-18 11:29         ` Peter Zijlstra
2011-05-18 11:57           ` Ingo Molnar
2011-05-18 11:32         ` Peter Zijlstra
2011-05-18 11:37           ` Avi Kivity
2011-05-18 12:35             ` Peter Zijlstra
2011-05-18 12:49               ` Avi Kivity
2011-06-03 14:41   ` Peter Zijlstra
2011-06-05  8:12     ` Avi Kivity
2011-06-03 14:41   ` Peter Zijlstra
2011-06-05  8:12     ` Avi Kivity
2011-05-12  9:33 ` [PATCH v1 0/5] KVM in-guest performance monitoring Joerg Roedel
2011-05-12  9:47   ` Jan Kiszka
2011-05-12  9:53     ` Avi Kivity
2011-05-12 13:11     ` Joerg Roedel
2011-05-12 13:23       ` Jan Kiszka
2011-05-12 13:43         ` Joerg Roedel [this message]
2011-05-12 13:31       ` Avi Kivity
2011-05-12 14:24         ` Joerg Roedel
2011-05-12 14:37           ` Avi Kivity
2011-05-12 14:45             ` Avi Kivity
2011-05-13 12:34             ` Joerg Roedel
2011-05-12  9:51   ` Avi Kivity
2011-05-12 13:06     ` Joerg Roedel
2011-05-12 13:38       ` Avi Kivity
2011-05-12 14:29         ` Joerg Roedel
2011-05-17  9:52 ` Avi Kivity
2011-06-01  9:45   ` Avi Kivity
2011-06-01 10:26     ` Peter Zijlstra
2011-06-01 11:26       ` Avi Kivity

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=20110512134339.GH8707@8bytes.org \
    --to=joro@8bytes.org \
    --cc=a.p.zijlstra@chello.nl \
    --cc=acme@ghostprotocols.net \
    --cc=avi@redhat.com \
    --cc=jan.kiszka@siemens.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    /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).