|
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: |
Avi Kivity <avi@xxxxxxxxxx> |
|
Date: |
Wed, 17 Nov 2010 10:58:22 +0200 |
|
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>, Jan Beulich <JBeulich@xxxxxxxxxx>, Eric Dumazet <dada1@xxxxxxxxxxxxx>, Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, "H. Peter Anvin" <hpa@xxxxxxxxx>, xiyou.wangcong@xxxxxxxxx, Linux Virtualization <virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx> |
|
Delivery-date: |
Wed, 17 Nov 2010 01:01:33 -0800 |
|
Envelope-to: |
www-data@xxxxxxxxxxxxxxxxxxx |
|
In-reply-to: |
<4CE397C8.9040901@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> |
|
Sender: |
xen-devel-bounces@xxxxxxxxxxxxxxxxxxx |
|
User-agent: |
Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.12) Gecko/20101103 Fedora/1.0-0.33.b2pre.fc14 Lightning/1.0b3pre Thunderbird/3.1.6 |
On 11/17/2010 10:52 AM, Jeremy Fitzhardinge wrote:
On 11/17/2010 12:31 AM, Jan Beulich wrote:
>>>> On 16.11.10 at 22:08, Jeremy Fitzhardinge<jeremy@xxxxxxxx> wrote:
>> +static inline void __ticket_enter_slowpath(struct arch_spinlock *lock)
>> +{
>> + if (sizeof(lock->tickets.tail) == sizeof(u8))
>> + asm (LOCK_PREFIX "orb %1, %0"
>> + : "+m" (lock->tickets.tail)
>> + : "i" (TICKET_SLOWPATH_FLAG) : "memory");
>> + else
>> + asm (LOCK_PREFIX "orw %1, %0"
>> + : "+m" (lock->tickets.tail)
>> + : "i" (TICKET_SLOWPATH_FLAG) : "memory");
>> +}
> Came only now to mind: Here and elsewhere, did you try using
> %z0 to have gcc produce the opcode suffix character, rather
> than having these somewhat ugly if()-s?
Actually in this case I'm pretty sure there's already a "set bit"
function which will do the job. set_bit(), I guess, though it takes a
bit number rather than a mask...
set_bit() operates on a long, while the intel manuals recommend against
operating on operands of different size, especially with locked
operations. I think newer processors have more relaxed requirements,
though.
--
error compiling committee.c: too many arguments to function
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
Home