| |
|
 |
|
 |
|
|
|
| |
|
|
xen-devel
[Xen-devel] Re: [PATCH 11/13] x86/ticketlock: only do kick after doing u
|
To: |
Peter Zijlstra <peterz@xxxxxxxxxxxxx> |
|
Subject: |
[Xen-devel] Re: [PATCH 11/13] x86/ticketlock: only do kick after doing unlock |
|
From: |
Jeremy Fitzhardinge <jeremy@xxxxxxxx> |
|
Date: |
Fri, 02 Sep 2011 12:34:14 -0700 |
|
Cc: |
Marcelo Tosatti <mtosatti@xxxxxxxxxx>, Nick Piggin <npiggin@xxxxxxxxx>, KVM <kvm@xxxxxxxxxxxxxxx>, the arch/x86 maintainers <x86@xxxxxxxxxx>, Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>, Srivatsa Vaddagiri <vatsa@xxxxxxxxxxxxxxxxxx>, Andi Kleen <andi@xxxxxxxxxxxxxx>, Avi Kivity <avi@xxxxxxxxxx>, Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>, "H. Peter Anvin" <hpa@xxxxxxxxx>, Ingo Molnar <mingo@xxxxxxx>, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>, Xen Devel <xen-devel@xxxxxxxxxxxxxxxxxxx> |
|
Delivery-date: |
Fri, 02 Sep 2011 12:34:54 -0700 |
|
Envelope-to: |
www-data@xxxxxxxxxxxxxxxxxxx |
|
In-reply-to: |
<1314974968.1861.3.camel@twins> |
|
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.1314922370.git.jeremy.fitzhardinge@xxxxxxxxxx> <8cd2c77886e2d3fcad8258aa62509b3b2fae5545.1314922370.git.jeremy.fitzhardinge@xxxxxxxxxx> <1314974968.1861.3.camel@twins> |
|
Sender: |
xen-devel-bounces@xxxxxxxxxxxxxxxxxxx |
|
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:6.0) Gecko/20110816 Thunderbird/6.0 |
On 09/02/2011 07:49 AM, Peter Zijlstra wrote:
> On Thu, 2011-09-01 at 17:55 -0700, Jeremy Fitzhardinge wrote:
>> From: Srivatsa Vaddagiri <vatsa@xxxxxxxxxxxxxxxxxx>
>>
>> We must release the lock before checking to see if the lock is in
>> slowpath or else there's a potential race where the lock enters the
>> slow path after the unlocker has checked the slowpath flag, but before
>> it has actually unlocked.
>>
>> Signed-off-by: Srivatsa Vaddagiri <vatsa@xxxxxxxxxxxxxxxxxx>
>> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
> Wouldn't it be much better to fold it back so that this bug never
> happens when you bisect?
Yes indeed.
J
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
| <Prev in Thread] |
Current Thread |
[Next in Thread>
|
- [Xen-devel] [PATCH 00/13] [PATCH RFC] Paravirtualized ticketlocks, Jeremy Fitzhardinge
- [Xen-devel] [PATCH 02/13] x86/ticketlock: collapse a layer of functions, Jeremy Fitzhardinge
- [Xen-devel] [PATCH 03/13] xen/pvticketlock: Xen implementation for PV ticket locks, Jeremy Fitzhardinge
- [Xen-devel] [PATCH 04/13] x86/pvticketlock: use callee-save for lock_spinning, Jeremy Fitzhardinge
- [Xen-devel] [PATCH 01/13] x86/spinlocks: replace pv spinlocks with pv ticketlocks, Jeremy Fitzhardinge
- [Xen-devel] [PATCH 11/13] x86/ticketlock: only do kick after doing unlock, Jeremy Fitzhardinge
- [Xen-devel] [PATCH 12/13] x86/pvticketlock: make sure unlock_kick pvop call is inlined, Jeremy Fitzhardinge
- [Xen-devel] [PATCH 09/13] x86/pvticketlocks: we only need to kick if there's waiters, Jeremy Fitzhardinge
- [Xen-devel] [PATCH 05/13] x86/ticketlocks: when paravirtualizing ticket locks, increment by 2, Jeremy Fitzhardinge
- [Xen-devel] [PATCH 10/13] xen/pvticket: allow interrupts to be enabled while blocking, Jeremy Fitzhardinge
- [Xen-devel] [PATCH 08/13] xen/pvticketlock: disable interrupts while blocking, Jeremy Fitzhardinge
|
|
|
| |
|
Home