xen-devel
[Xen-devel] Re: [PATCH 13/14] x86/ticketlock: add slowpath logic
To: |
"Jeremy Fitzhardinge" <jeremy@xxxxxxxx> |
Subject: |
[Xen-devel] Re: [PATCH 13/14] x86/ticketlock: add slowpath logic |
From: |
"Jan Beulich" <JBeulich@xxxxxxxxxx> |
Date: |
Wed, 17 Nov 2010 09:34:40 +0000 |
Cc: |
Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>, Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>, Nick Piggin <npiggin@xxxxxxxxx>, Peter Zijlstra <peterz@xxxxxxxxxxxxx>, Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>, Srivatsa Vaddagiri <vatsa@xxxxxxxxxxxxxxxxxx>, Eric Dumazet <dada1@xxxxxxxxxxxxx>, Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Avi Kivity <avi@xxxxxxxxxx>, "H. Peter Anvin" <hpa@xxxxxxxxx>, xiyou.wangcong@xxxxxxxxx, Linux Virtualization <virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx> |
Delivery-date: |
Wed, 17 Nov 2010 01:35:17 -0800 |
Envelope-to: |
www-data@xxxxxxxxxxxxxxxxxxx |
In-reply-to: |
<4CE39B7A.1080706@xxxxxxxx> |
List-help: |
<mailto:xen-devel-request@lists.xensource.com?subject=help> |
List-id: |
Xen developer discussion <xen-devel.lists.xensource.com> |
List-post: |
<mailto:xen-devel@lists.xensource.com> |
List-subscribe: |
<http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe> |
List-unsubscribe: |
<http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe> |
References: |
<cover.1289940821.git.jeremy.fitzhardinge@xxxxxxxxxx><cover.1289940821.git.jeremy.fitzhardinge@xxxxxxxxxx> <97ed99ae9160bdb6477284b333bd6708fb7a19cb.1289940821.git.jeremy.fitzhardinge@xxxxxxxxxx> <4CE3A1060200007800022B04@xxxxxxxxxxxxxxxxxx> <4CE397C8.9040901@xxxxxxxx> <4CE398A0.3040105@xxxxxxxx> <4CE39B7A.1080706@xxxxxxxx> |
Sender: |
xen-devel-bounces@xxxxxxxxxxxxxxxxxxx |
>>> On 17.11.10 at 10:08, Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
> On 11/17/2010 12:56 AM, Jeremy Fitzhardinge wrote:
>> On 11/17/2010 12:52 AM, Jeremy Fitzhardinge wrote:
>>> But, yes, %z0 sounds interesting. Is it documented anywhere? I think
>>> I've tried to use it in the past and run into gcc bugs.
>> This one: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590
>>
>> Should be OK in this case because there's no 64-bit values to be seen...
> Hm, it fails when __ticket_t is 16 bits:
>
> /home/jeremy/git/linux/arch/x86/include/asm/spinlock.h: Assembler messages:
> /home/jeremy/git/linux/arch/x86/include/asm/spinlock.h:73: Error: suffix
> or operands invalid for `or'
>
> lock; ors $1, 2(%rbx) #,
>
>
> So I don't think that's going to work out...
Indeed, it's only with 4.5 that non-float operands are properly
supported here. Sad.
Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|