All of lore.kernel.org
 help / color / mirror / Atom feed
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Kevin Hao <haokexin@gmail.com>
Cc: Bhushan Bharat-R65777 <R65777@freescale.com>,
	"tiejun.chen" <tiejun.chen@windriver.com>,
	Caraman Mihai Claudiu-B02008 <B02008@freescale.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Wood Scott-B07421 <B07421@freescale.com>,
	"agraf@suse.de" <agraf@suse.de>,
	"kvm-ppc@vger.kernel.org" <kvm-ppc@vger.kernel.org>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [RFC][KVM][PATCH 1/1] kvm:ppc:booke-64: soft-disable interrupts
Date: Thu, 09 May 2013 22:26:52 +1000	[thread overview]
Message-ID: <1368102412.25488.182.camel@pasglop> (raw)
In-Reply-To: <20130509082112.GE2263@pek-khao-d1.corp.ad.wrs.com>

On Thu, 2013-05-09 at 16:21 +0800, Kevin Hao wrote:
> > Is it because that we cannot afford to lose perfmon interrupt for
> more accurate capturing of data ?
> 
> Yes, I think this will definitely improve the perf sample quality.

This is one of the primary reason why we implemented lazy disabling in
the first place and why I recently reworked it to decrease the periods
where we are hard disabled.

The other reasons are that storing bytes to the PACA is faster than
manipulating EE on many processors.

Cheers,
Ben.

WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Kevin Hao <haokexin@gmail.com>
Cc: Wood Scott-B07421 <B07421@freescale.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Caraman Mihai Claudiu-B02008 <B02008@freescale.com>,
	"agraf@suse.de" <agraf@suse.de>,
	"kvm-ppc@vger.kernel.org" <kvm-ppc@vger.kernel.org>,
	"tiejun.chen" <tiejun.chen@windriver.com>,
	Bhushan Bharat-R65777 <R65777@freescale.com>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [RFC][KVM][PATCH 1/1] kvm:ppc:booke-64: soft-disable interrupts
Date: Thu, 09 May 2013 22:26:52 +1000	[thread overview]
Message-ID: <1368102412.25488.182.camel@pasglop> (raw)
In-Reply-To: <20130509082112.GE2263@pek-khao-d1.corp.ad.wrs.com>

On Thu, 2013-05-09 at 16:21 +0800, Kevin Hao wrote:
> > Is it because that we cannot afford to lose perfmon interrupt for
> more accurate capturing of data ?
> 
> Yes, I think this will definitely improve the perf sample quality.

This is one of the primary reason why we implemented lazy disabling in
the first place and why I recently reworked it to decrease the periods
where we are hard disabled.

The other reasons are that storing bytes to the PACA is faster than
manipulating EE on many processors.

Cheers,
Ben.

WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Kevin Hao <haokexin@gmail.com>
Cc: Bhushan Bharat-R65777 <R65777@freescale.com>,
	"tiejun.chen" <tiejun.chen@windriver.com>,
	Caraman Mihai Claudiu-B02008 <B02008@freescale.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Wood Scott-B07421 <B07421@freescale.com>,
	"agraf@suse.de" <agraf@suse.de>,
	"kvm-ppc@vger.kernel.org" <kvm-ppc@vger.kernel.org>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [RFC][KVM][PATCH 1/1] kvm:ppc:booke-64: soft-disable interrupts
Date: Thu, 09 May 2013 12:26:52 +0000	[thread overview]
Message-ID: <1368102412.25488.182.camel@pasglop> (raw)
In-Reply-To: <20130509082112.GE2263@pek-khao-d1.corp.ad.wrs.com>

On Thu, 2013-05-09 at 16:21 +0800, Kevin Hao wrote:
> > Is it because that we cannot afford to lose perfmon interrupt for
> more accurate capturing of data ?
> 
> Yes, I think this will definitely improve the perf sample quality.

This is one of the primary reason why we implemented lazy disabling in
the first place and why I recently reworked it to decrease the periods
where we are hard disabled.

The other reasons are that storing bytes to the PACA is faster than
manipulating EE on many processors.

Cheers,
Ben.



  reply	other threads:[~2013-05-09 12:26 UTC|newest]

Thread overview: 88+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-06  3:10 [RFC][KVM][PATCH 1/1] kvm:ppc:booke-64: soft-disable interrupts Tiejun Chen
2013-05-06  3:10 ` Tiejun Chen
2013-05-06  3:10 ` Tiejun Chen
2013-05-06  3:13 ` tiejun.chen
2013-05-06  3:13   ` tiejun.chen
2013-05-06  3:13   ` tiejun.chen
2013-05-06 23:50   ` Scott Wood
2013-05-06 23:50     ` Scott Wood
2013-05-07  1:56     ` tiejun.chen
2013-05-07  1:56       ` tiejun.chen
2013-05-07  1:56       ` tiejun.chen
2013-05-07  2:06       ` Scott Wood
2013-05-07  2:06         ` Scott Wood
2013-05-07  2:43         ` tiejun.chen
2013-05-07  2:43           ` tiejun.chen
2013-05-07  2:43           ` tiejun.chen
2013-05-07  3:04           ` Scott Wood
2013-05-07  3:04             ` Scott Wood
2013-05-08 13:14         ` Caraman Mihai Claudiu-B02008
2013-05-08 13:14           ` Caraman Mihai Claudiu-B02008
2013-05-09  7:33           ` Bhushan Bharat-R65777
2013-05-09  7:33             ` Bhushan Bharat-R65777
2013-05-09  7:47             ` tiejun.chen
2013-05-09  7:47               ` tiejun.chen
2013-05-09  7:47               ` tiejun.chen
2013-05-09  7:51               ` Bhushan Bharat-R65777
2013-05-09  7:51                 ` Bhushan Bharat-R65777
2013-05-09  8:04                 ` tiejun.chen
2013-05-09  8:04                   ` tiejun.chen
2013-05-09  8:04                   ` tiejun.chen
2013-05-09  8:08                 ` Kevin Hao
2013-05-09  8:08                   ` Kevin Hao
2013-05-09  8:08                   ` Kevin Hao
2013-05-09  8:12                   ` Bhushan Bharat-R65777
2013-05-09  8:12                     ` Bhushan Bharat-R65777
2013-05-09  8:17                     ` tiejun.chen
2013-05-09  8:17                       ` tiejun.chen
2013-05-09  8:17                       ` tiejun.chen
2013-05-09  8:26                       ` Bhushan Bharat-R65777
2013-05-09  8:26                         ` Bhushan Bharat-R65777
2013-05-09  8:21                     ` Kevin Hao
2013-05-09  8:21                       ` Kevin Hao
2013-05-09  8:21                       ` Kevin Hao
2013-05-09 12:26                       ` Benjamin Herrenschmidt [this message]
2013-05-09 12:26                         ` Benjamin Herrenschmidt
2013-05-09 12:26                         ` Benjamin Herrenschmidt
2013-05-09  8:23           ` Bhushan Bharat-R65777
2013-05-09  8:23             ` Bhushan Bharat-R65777
2013-05-09  9:44             ` tiejun.chen
2013-05-09  9:44               ` tiejun.chen
2013-05-09  9:44               ` tiejun.chen
2013-05-09 10:00               ` Bhushan Bharat-R65777
2013-05-09 10:00                 ` Bhushan Bharat-R65777
2013-05-09 10:18                 ` [RFC][PATCH " tiejun.chen
2013-05-09 10:18                   ` [RFC][KVM][PATCH " tiejun.chen
2013-05-09 10:18                   ` tiejun.chen
2013-05-09 11:21                   ` Bhushan Bharat-R65777
2013-05-09 11:21                     ` Bhushan Bharat-R65777
2013-05-09 11:35                     ` tiejun.chen
2013-05-09 11:35                       ` tiejun.chen
2013-05-09 11:35                       ` tiejun.chen
2013-05-09 12:37               ` [RFC][PATCH " Benjamin Herrenschmidt
2013-05-09 12:37                 ` [RFC][KVM][PATCH " Benjamin Herrenschmidt
2013-05-09 12:37                 ` Benjamin Herrenschmidt
2013-05-09 13:28                 ` David Laight
2013-05-09 13:28                   ` David Laight
2013-05-09 13:28                   ` David Laight
2013-05-09 22:01                   ` Benjamin Herrenschmidt
2013-05-09 22:01                     ` Benjamin Herrenschmidt
2013-05-09 22:01                     ` Benjamin Herrenschmidt
2013-05-09 14:13                 ` Chen, Tiejun
2013-05-09 14:13                   ` Chen, Tiejun
2013-05-09 14:13                   ` Chen, Tiejun
2013-05-09 21:27                 ` Scott Wood
2013-05-09 21:27                   ` Scott Wood
2013-05-09 22:07                   ` [RFC][PATCH " Benjamin Herrenschmidt
2013-05-09 22:07                     ` [RFC][KVM][PATCH " Benjamin Herrenschmidt
2013-05-09 22:07                     ` Benjamin Herrenschmidt
2013-05-09 22:13                     ` Scott Wood
2013-05-09 22:13                       ` Scott Wood
2013-05-10 14:12                     ` Kevin Hao
2013-05-10 14:12                       ` Kevin Hao
2013-05-10 14:12                       ` Kevin Hao
2013-05-10 21:49                       ` Benjamin Herrenschmidt
2013-05-10 21:49                         ` Benjamin Herrenschmidt
2013-05-10 21:49                         ` Benjamin Herrenschmidt
2013-05-10 21:50                         ` Benjamin Herrenschmidt
2013-05-10 21:50                           ` Benjamin Herrenschmidt

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=1368102412.25488.182.camel@pasglop \
    --to=benh@kernel.crashing.org \
    --cc=B02008@freescale.com \
    --cc=B07421@freescale.com \
    --cc=R65777@freescale.com \
    --cc=agraf@suse.de \
    --cc=haokexin@gmail.com \
    --cc=kvm-ppc@vger.kernel.org \
    --cc=kvm@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=tiejun.chen@windriver.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.