linux-kernel - Re: Preemptable Ticket Spinlock

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-id: <CAJocwcfmqOzB2q7Vugkyydq5WSjbYQ06z9xLxY4qdyznCnEJGg@mail.gmail.com>
Date:	Mon, 22 Apr 2013 16:05:30 -0400
From:	Jiannan Ouyang <ouyang@...pitt.edu>
To:	Rik van Riel <riel@...hat.com>
Cc:	Peter Zijlstra <peterz@...radead.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Raghavendra K T <raghavendra.kt@...ux.vnet.ibm.com>,
	Avi Kivity <avi.kivity@...il.com>,
	Gleb Natapov <gleb@...hat.com>, Ingo Molnar <mingo@...hat.com>,
	Marcelo Tosatti <mtosatti@...hat.com>,
	Srikar <srikar@...ux.vnet.ibm.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	"Nikunj A. Dadhania" <nikunj@...ux.vnet.ibm.com>,
	KVM <kvm@...r.kernel.org>, Thomas Gleixner <tglx@...utronix.de>,
	Chegu Vinod <chegu_vinod@...com>,
	"Andrew M. Theurer" <habanero@...ux.vnet.ibm.com>,
	Srivatsa Vaddagiri <srivatsa.vaddagiri@...il.com>,
	Andrew Jones <drjones@...hat.com>,
	Karen Noel <knoel@...hat.com>
Subject: Re: Preemptable Ticket Spinlock

On Mon, Apr 22, 2013 at 3:56 PM, Rik van Riel <riel@...hat.com> wrote:
> On 04/22/2013 03:49 PM, Peter Zijlstra wrote:
>>
>> On Mon, 2013-04-22 at 08:52 -0400, Rik van Riel wrote:
>
>
>>> If the native spin_lock code has been called already at
>>> that time, the native code would still need to be modified
>>> to increment the ticket number by 2, so we end up with a
>>> compatible value in each spin lock's .tickets field, and
>>> prevent a deadlock after we switch over to the paravirt
>>> variant.
>>
>>
>> I thought the stuff already made it upstream, but apparently not; the
>> lastest posting I'm aware of is here:
>>
>>    https://lkml.org/lkml/2012/5/2/105
>>
>> That stuff changes the normal ticket increment as well..
>
>
> Jiannan,
>
> It looks like the patch above could make a good patch
> 1 (or 2) in your patch series :)
>
> --
> All rights reversed

Yes.
I'm going to move my code, updated with Rik's suggestions, to paravirt
ops based on Jeremy's patch.
I'll post a new patch series soon.

Thanks to everyone for the great feedback!
--Jiannan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/