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From: Zachary Amsden <zach@vmware.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: virtualization <virtualization@lists.osdl.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Roland McGrath <roland@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [patch] paravirt: VDSO page is essential
Date: Mon, 05 Mar 2007 12:42:25 -0800	[thread overview]
Message-ID: <45EC80B1.8030901@vmware.com> (raw)
In-Reply-To: <20070305201957.GA733@elte.hu>

Ingo Molnar wrote:
> there's no need to disable the VDSO for old userspace ...
>   

Well, apart from the obvious question to which nobody actually knows the 
answer, (how many people run old user space that required 
CONFIG_COMPAT_VDSO), what do you think of reversing the boot option?

vdso=enabled (default - turn on VDSO on normal boots)
vdso=disabled (turn off VDSO unconditionally)
[vdso=compat] (default for COMPAT_VDSO - keep VDSO only when mapped at 
compat location.  Note the option is not required to be implemented 
because it is logically implied from vdso=enabled && COMPAT_VDSO and the 
default boot behavior)
vdso=force (keep VDSO even when moved to a new location and COMPAT_VDSO 
is enabled).

In our case, installing VMware tools in the guest would then detect if 
userspace supports VDSO or if it requires COMPAT_VDSO and would then set 
boot parameters for the kernel appropriately.  And the native boot and 
kvm paravirt-ops boot are completely unaffected.

Zach

WARNING: multiple messages have this Message-ID (diff)
From: Zachary Amsden <zach@vmware.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>, Rusty Russell <rusty@rustcorp.com.au>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org, Roland McGrath <roland@redhat.com>,
	virtualization <virtualization@lists.osdl.org>
Subject: Re: [patch] paravirt: VDSO page is essential
Date: Mon, 05 Mar 2007 12:42:25 -0800	[thread overview]
Message-ID: <45EC80B1.8030901@vmware.com> (raw)
In-Reply-To: <20070305201957.GA733@elte.hu>

Ingo Molnar wrote:
> there's no need to disable the VDSO for old userspace ...
>   

Well, apart from the obvious question to which nobody actually knows the 
answer, (how many people run old user space that required 
CONFIG_COMPAT_VDSO), what do you think of reversing the boot option?

vdso=enabled (default - turn on VDSO on normal boots)
vdso=disabled (turn off VDSO unconditionally)
[vdso=compat] (default for COMPAT_VDSO - keep VDSO only when mapped at 
compat location.  Note the option is not required to be implemented 
because it is logically implied from vdso=enabled && COMPAT_VDSO and the 
default boot behavior)
vdso=force (keep VDSO even when moved to a new location and COMPAT_VDSO 
is enabled).

In our case, installing VMware tools in the guest would then detect if 
userspace supports VDSO or if it requires COMPAT_VDSO and would then set 
boot parameters for the kernel appropriately.  And the native boot and 
kvm paravirt-ops boot are completely unaffected.

Zach

  reply	other threads:[~2007-03-05 20:42 UTC|newest]

Thread overview: 123+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-03-05 12:06 [patch] paravirt: VDSO page is essential Ingo Molnar
2007-03-05 12:36 ` Avi Kivity
2007-03-05 12:40   ` Ingo Molnar
2007-03-05 13:00     ` Avi Kivity
2007-03-05 13:32       ` Rusty Russell
2007-03-05 14:28   ` Andi Kleen
2007-03-05 13:48     ` Ingo Molnar
2007-03-05 14:58       ` Andi Kleen
2007-03-05 13:59         ` Ingo Molnar
2007-03-05 14:10           ` Avi Kivity
2007-03-05 14:10             ` Ingo Molnar
2007-03-05 13:28 ` Rusty Russell
2007-03-05 13:38   ` Ingo Molnar
2007-03-05 14:34   ` Andi Kleen
2007-03-05 13:46     ` [patch] paravirt: re-enable COMPAT_VDSO Ingo Molnar
2007-03-05 13:48     ` [patch] paravirt: VDSO page is essential Ingo Molnar
2007-03-05 20:11     ` Zachary Amsden
2007-03-05 20:11       ` Zachary Amsden
2007-03-05 20:16       ` Andi Kleen
2007-03-05 20:33         ` Zachary Amsden
2007-03-05 20:19       ` Ingo Molnar
2007-03-05 20:19         ` Ingo Molnar
2007-03-05 20:42         ` Zachary Amsden [this message]
2007-03-05 20:42           ` Zachary Amsden
2007-03-06  0:57   ` Rusty Russell
2007-03-06  1:03     ` Zachary Amsden
2007-03-06  1:11       ` Rusty Russell
2007-03-06  1:11         ` Rusty Russell
2007-03-06  1:14       ` Jeremy Fitzhardinge
2007-03-06  1:51         ` Zachary Amsden
2007-03-06  1:53           ` Jeremy Fitzhardinge
2007-03-06  1:53             ` Jeremy Fitzhardinge
2007-03-06  8:19             ` Xen & VMI? Ingo Molnar
2007-03-06  8:19               ` Ingo Molnar
2007-03-06  8:37               ` Gerd Hoffmann
2007-03-06  8:48                 ` Zachary Amsden
2007-03-06  8:52                 ` Ingo Molnar
2007-03-06  8:52                   ` Ingo Molnar
2007-03-06  9:03                   ` Zachary Amsden
2007-03-06  9:03                     ` Zachary Amsden
2007-03-06  9:10                     ` Ingo Molnar
2007-03-06  9:10                       ` Ingo Molnar
2007-03-06  9:15                   ` Gerd Hoffmann
2007-03-06  9:15                     ` Gerd Hoffmann
2007-03-06  9:34                     ` Ingo Molnar
2007-03-06 10:15                       ` Gerd Hoffmann
2007-03-06 10:15                         ` Gerd Hoffmann
2007-03-06 10:26                         ` Ingo Molnar
2007-03-06 10:26                           ` Ingo Molnar
2007-03-06 11:04                           ` Gerd Hoffmann
2007-03-06 11:59                             ` Ingo Molnar
2007-03-06 12:34                               ` Gerd Hoffmann
2007-03-06 15:03                               ` Anthony Liguori
2007-03-06 15:03                                 ` Anthony Liguori
2007-03-06 17:17                                 ` Nakajima, Jun
2007-03-06 17:17                                   ` Nakajima, Jun
2007-03-06 17:32                                   ` Anthony Liguori
2007-03-06 20:37                                   ` Ingo Molnar
2007-03-06 21:02                                     ` Jeremy Fitzhardinge
2007-03-06 21:02                                       ` Jeremy Fitzhardinge
2007-03-06 21:11                                       ` Ingo Molnar
2007-03-06 21:11                                         ` Ingo Molnar
2007-03-06 21:13                                         ` Jeremy Fitzhardinge
2007-03-06 21:13                                           ` Jeremy Fitzhardinge
2007-03-06 21:20                                           ` Ingo Molnar
2007-03-06 21:20                                             ` Ingo Molnar
2007-03-06 21:46                                             ` Jeremy Fitzhardinge
2007-03-06 21:46                                               ` Jeremy Fitzhardinge
2007-03-06 21:35                                     ` Nakajima, Jun
2007-03-06 21:35                                       ` Nakajima, Jun
2007-03-07  0:44                                     ` Rusty Russell
2007-03-07  0:54                                       ` Anthony Liguori
2007-03-07  0:54                                         ` Anthony Liguori
2007-03-07  3:06                                       ` Zachary Amsden
2007-03-07  8:15                                       ` Ingo Molnar
2007-03-07  8:15                                         ` Ingo Molnar
2007-03-07  9:17                                         ` Zachary Amsden
2007-03-07 11:15                                           ` Thomas Gleixner
2007-03-07 19:14                                         ` Dan Hecht
2007-03-06 16:27                               ` Jeremy Fitzhardinge
2007-03-06 17:11                                 ` Ingo Molnar
2007-03-06 17:33                                   ` Jeremy Fitzhardinge
2007-03-07  2:16                                   ` Zachary Amsden
2007-03-07  2:16                                     ` Zachary Amsden
2007-03-06  9:55                     ` Avi Kivity
2007-03-06 10:23                       ` Gerd Hoffmann
2007-03-06 10:31                         ` Ingo Molnar
2007-03-06 19:46                   ` Chris Wright
2007-03-06 19:46                     ` Chris Wright
2007-03-06 20:30                     ` Ingo Molnar
2007-03-06 20:30                       ` Ingo Molnar
2007-03-06 20:53                       ` Chris Wright
2007-03-06 21:03                         ` Ingo Molnar
2007-03-06 21:03                           ` Ingo Molnar
2007-03-06 21:28                           ` Chris Wright
2007-03-06 21:28                             ` Chris Wright
2007-03-07  2:35                             ` Zachary Amsden
2007-03-07  2:35                               ` Zachary Amsden
2007-03-06  9:07               ` Jeremy Fitzhardinge
2007-03-06  9:07                 ` Jeremy Fitzhardinge
2007-03-06  9:26                 ` Ingo Molnar
2007-03-06  9:26                   ` Ingo Molnar
2007-03-06 16:42                   ` Jeremy Fitzhardinge
2007-03-06 16:42                     ` Jeremy Fitzhardinge
2007-03-06 17:18                     ` Ingo Molnar
2007-03-06 17:18                       ` Ingo Molnar
2007-03-06 18:04                       ` Jeremy Fitzhardinge
2007-03-06 18:04                         ` Jeremy Fitzhardinge
2007-03-06  7:35         ` [patch] paravirt: VDSO page is essential Ingo Molnar
2007-03-06  7:35           ` Ingo Molnar
2007-03-06  7:42           ` Zachary Amsden
2007-03-06  7:50             ` Ingo Molnar
2007-03-06  7:50               ` Ingo Molnar
2007-03-06 18:48             ` Jeremy Fitzhardinge
2007-03-06 18:48               ` Jeremy Fitzhardinge
2007-03-05 14:27 ` Andi Kleen
2007-03-05 21:58   ` Roland McGrath
2007-03-05 22:01     ` Jeremy Fitzhardinge
2007-03-05 22:58       ` Roland McGrath
2007-03-05 23:03         ` Jeremy Fitzhardinge
2007-03-06  8:34         ` Ingo Molnar
2007-03-06  9:13           ` Roland McGrath
2007-03-06  9:14             ` Jeremy Fitzhardinge

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