From: "H. Peter Anvin" <hpa@zytor.com>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
"David S. Miller" <davem@davemloft.net>,
David Daney <david.daney@cavium.com>,
Michael Ellerman <michael@ellerman.id.au>,
Jan Glauber <jang@linux.vnet.ibm.com>,
Jason Baron <jbaron@redhat.com>,
the arch/x86 maintainers <x86@kernel.org>,
Xen Devel <xen-devel@lists.xensource.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <peterz@infradead.org>,
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Subject: Re: [PATCH RFC V4 09/10] x86/jump_label: use GENERIC_NOP5_ATOMIC instead of jmp5 +0
Date: Fri, 14 Oct 2011 14:52:09 -0700 [thread overview]
Message-ID: <4E98AF09.6040306@zytor.com> (raw)
In-Reply-To: <4E9716B8.8050406@goop.org>
On 10/13/2011 09:50 AM, Jeremy Fitzhardinge wrote:
> On 10/13/2011 08:40 AM, H. Peter Anvin wrote:
>> On 10/12/2011 05:08 PM, Jeremy Fitzhardinge wrote:
>>> From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
>>>
>>> GENERIC_NOP5_ATOMIC should make a better nop.
>>>
>> On 32 bits, yes. On 64 bits you should use P6_NOP5_ATOMIC.
>
> So the cleanest way of fixing that is to make the GENERIC_NOP* be
> defined to P6_NOP* on 64-bit then? Assuming I'm correct in guessing
> that the intent of GENERIC_NOP* is "a basically good-enough NOP that
> will work on any x86".
>
No, GENERIC_NOPs are not valid on 64 bits at all.
-hpa
next prev parent reply other threads:[~2011-10-14 21:52 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-13 0:08 [PATCH RFC V4 00/10] jump-label: allow early jump_label_enable() Jeremy Fitzhardinge
[not found] ` <cover.1318464413.git.jeremy.fitzhardinge@citrix.com>
2011-10-13 0:08 ` [PATCH RFC V4 01/10] jump_label: use proper atomic_t initializer Jeremy Fitzhardinge
2011-10-13 0:08 ` [PATCH RFC V4 02/10] stop_machine: make stop_machine safe and efficient to call early Jeremy Fitzhardinge
2011-10-13 0:08 ` [PATCH RFC V4 03/10] jump_label: if a key has already been initialized, don't nop it out Jeremy Fitzhardinge
2011-10-13 0:08 ` [PATCH RFC V4 04/10] x86/jump_label: drop arch_jump_label_text_poke_early() Jeremy Fitzhardinge
2011-10-13 10:15 ` Peter Zijlstra
2011-10-13 0:08 ` [PATCH RFC V4 05/10] sparc/jump_label: " Jeremy Fitzhardinge
2011-10-13 0:08 ` [PATCH RFC V4 06/10] jump_label: add arch_jump_label_transform_static() to optimise non-live code updates Jeremy Fitzhardinge
2011-10-13 10:32 ` Peter Zijlstra
2011-10-13 13:54 ` Jason Baron
2011-10-13 15:29 ` Peter Zijlstra
2011-10-13 15:55 ` Jason Baron
2011-10-13 16:32 ` Peter Zijlstra
2011-10-13 0:08 ` [PATCH RFC V4 07/10] s390/jump-label: add arch_jump_label_transform_static() Jeremy Fitzhardinge
2011-10-13 0:08 ` [PATCH RFC V4 08/10] x86/jump_label: " Jeremy Fitzhardinge
2011-10-13 10:36 ` Peter Zijlstra
2011-10-13 0:08 ` [PATCH RFC V4 09/10] x86/jump_label: use GENERIC_NOP5_ATOMIC instead of jmp5 +0 Jeremy Fitzhardinge
2011-10-13 15:40 ` H. Peter Anvin
2011-10-13 16:50 ` Jeremy Fitzhardinge
2011-10-14 21:52 ` H. Peter Anvin [this message]
2011-10-13 16:57 ` Jeremy Fitzhardinge
2011-10-13 18:37 ` Steven Rostedt
2011-10-14 21:53 ` H. Peter Anvin
2011-10-15 0:22 ` Steven Rostedt
2011-10-14 21:53 ` H. Peter Anvin
2011-10-13 0:08 ` [PATCH RFC V4 10/10] jump-label: initialize jump-label subsystem much earlier Jeremy Fitzhardinge
2011-10-13 10:43 ` Peter Zijlstra
2011-10-13 13:59 ` Jason Baron
2011-10-13 16:56 ` Jeremy Fitzhardinge
2011-10-14 21:51 ` Jeremy Fitzhardinge
2011-10-15 8:42 ` Peter Zijlstra
2011-10-16 1:52 ` Jeremy Fitzhardinge
2011-10-18 11:02 ` Peter Zijlstra
2011-10-25 17:56 ` Jeremy Fitzhardinge
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