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From: Ulrich Drepper <drepper@gmail.com>
To: Chris Mason <chris.mason@oracle.com>, Ingo Molnar <mingo@elte.hu>,
	Nick Piggin <npiggin@suse.de>,
	Jeremy Fitzhardinge <jeremy@goop.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Avi Kivity <avi@redhat.com>,
	Arjan van de Ven <arjan@infradead.org>
Subject: Re: [benchmark] 1% performance overhead of paravirt_ops on native  kernels
Date: Tue, 2 Jun 2009 07:49:32 -0700	[thread overview]
Message-ID: <a36005b50906020749p22b89693k5c4ae171d18966a7@mail.gmail.com> (raw)
In-Reply-To: <20090602141802.GC3914@think>

On Tue, Jun 2, 2009 at 7:18 AM, Chris Mason <chris.mason@oracle.com> wrote:
> I'm not suggesting we should take broken code, or that we should lower
> standards just for xen.  But, expecting the xen developers to fix the 1%
> hit on a very specific micro-benchmark is not a way to promote new
> projects for the kernel, and it isn't a good way to convince people to
> do continued development in mainline instead of in private trees.

It's not a new project which needs to be treated with kid's gloves.
And one be sure that once the code is in the tree those interested
parties will not be as strongly motivated to fix any problem like
this.  Ingo pointed to a way which doesn't negatively impact the
performance of the Xen kernel and reduces the overhead (dynamic
patching).  Just get started on this (and general cleanup) and this
whole argument will go away.

I find it ridiculous to use the "but it's used" argument to try to
force the code into the kernel.  By this argument you can say the same
about crap like ndiswrapper and similarly harmful code.

  reply	other threads:[~2009-06-02 14:57 UTC|newest]

Thread overview: 80+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-14  0:16 Performance overhead of paravirt_ops on native identified Jeremy Fitzhardinge
2009-05-14  1:10 ` H. Peter Anvin
2009-05-14  8:25   ` Peter Zijlstra
2009-05-14 14:05     ` H. Peter Anvin
2009-05-14 17:36   ` Jeremy Fitzhardinge
2009-05-14 17:50     ` H. Peter Anvin
2009-05-14  8:05 ` [Xen-devel] Performance overhead of paravirt_ops on nativeidentified Jan Beulich
2009-05-14  8:33   ` Peter Zijlstra
2009-05-14 17:45   ` Jeremy Fitzhardinge
2009-05-15  8:10     ` Jan Beulich
2009-05-15 18:50       ` Jeremy Fitzhardinge
2009-05-18  7:19         ` Jan Beulich
2009-05-20 22:42           ` Jeremy Fitzhardinge
2009-05-15 18:18 ` [tip:x86/urgent] x86: Fix performance regression caused by paravirt_ops on native kernels tip-bot for Jeremy Fitzhardinge
2009-05-21 22:42 ` Performance overhead of paravirt_ops on native identified Chuck Ebbert
2009-05-21 22:48   ` Jeremy Fitzhardinge
2009-05-21 23:10     ` H. Peter Anvin
2009-05-22  1:26     ` Xin, Xiaohui
2009-05-22  3:39       ` H. Peter Anvin
2009-05-22  4:27       ` Jeremy Fitzhardinge
2009-05-22  5:59         ` Xin, Xiaohui
2009-05-22 16:33           ` H. Peter Anvin
2009-05-22 22:44             ` Jeremy Fitzhardinge
2009-05-22 22:47               ` H. Peter Anvin
2009-05-25  9:15 ` [benchmark] 1% performance overhead of paravirt_ops on native kernels Ingo Molnar
2009-05-26 18:42   ` Jeremy Fitzhardinge
2009-05-28  6:17     ` Nick Piggin
2009-05-28 20:57       ` Jeremy Fitzhardinge
2009-05-30 10:23       ` Ingo Molnar
2009-06-02 14:18         ` Chris Mason
2009-06-02 14:49           ` Ulrich Drepper [this message]
2009-06-02 15:03             ` Chris Mason
2009-06-02 15:22               ` Ulrich Drepper
2009-06-02 16:20                 ` Chris Mason
2009-06-02 18:13                   ` Pekka Enberg
2009-06-02 18:06               ` Pekka Enberg
2009-06-02 18:27                 ` Chris Mason
2009-06-03  6:33             ` Jeremy Fitzhardinge
2009-06-02 19:14           ` Thomas Gleixner
2009-06-02 19:51             ` Chris Mason
2009-06-03 12:38         ` Rusty Russell
2009-06-03 16:09           ` Linus Torvalds
     [not found]             ` <200906041554.37102.rusty@rustcorp.com.au>
2009-06-04 15:02               ` Linus Torvalds
2009-06-04 21:52                 ` Dave McCracken
2009-06-05  7:31                   ` Gerd Hoffmann
2009-06-05 14:31                     ` Rusty Russell
2009-06-06 18:54                   ` Anders K. Pedersen
2009-06-05  4:46                 ` Rusty Russell
2009-06-05 14:54                   ` Linus Torvalds
2009-06-07  0:53                     ` Rusty Russell
2009-06-08 14:53                       ` Linus Torvalds
2009-06-09  9:39                 ` Nick Piggin
2009-06-09 11:17                   ` Ingo Molnar
2009-06-09 12:10                     ` Nick Piggin
2009-06-09 12:25                       ` Ingo Molnar
2009-06-09 12:42                         ` Nick Piggin
2009-06-09 12:56                         ` Avi Kivity
2009-06-09 15:18                         ` Linus Torvalds
2009-06-09 23:33                         ` Paul Mackerras
2009-06-10  1:26                           ` Ingo Molnar
2009-06-09 15:07                       ` Linus Torvalds
2009-06-09 15:09                     ` H. Peter Anvin
2009-06-09 18:06                       ` Linus Torvalds
2009-06-09 18:07                         ` Linus Torvalds
2009-06-09 22:48                           ` Matthew Garrett
2009-06-09 22:54                             ` H. Peter Anvin
2009-06-09 14:54                   ` Linus Torvalds
2009-06-09 14:57                     ` Ingo Molnar
2009-06-09 15:55                       ` Avi Kivity
2009-06-09 15:38                     ` Nick Piggin
2009-06-09 16:00                       ` Linus Torvalds
2009-06-09 16:21                         ` Nick Piggin
2009-06-09 16:26                           ` Linus Torvalds
2009-06-09 16:45                             ` Nick Piggin
2009-06-09 17:08                               ` Linus Torvalds
2009-06-10  5:53                                 ` Nick Piggin
2009-06-17  9:40                                   ` Pavel Machek
2009-06-17  9:56                                     ` Nick Piggin
2009-06-10  6:29                             ` Peter Zijlstra
  -- strict thread matches above, loose matches on Subject: below --
2009-06-04  6:58 Rusty Russell

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