From mboxrd@z Thu Jan  1 00:00:00 1970
From: Julien Grall <julien.grall@linaro.org>
Subject: Re: [PATCH v3 18/18] xen/arm: IRQ: Handle multiple
	action per IRQ
Date: Thu, 17 Apr 2014 13:18:06 +0100
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To: Ian Campbell <Ian.Campbell@citrix.com>
Cc: xen-devel@lists.xenproject.org, Keir Fraser <keir@xen.org>, stefano.stabellini@citrix.com, Jan Beulich <JBeulich@suse.com>, tim@xen.org
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On 04/17/2014 12:36 PM, Ian Campbell wrote:
> On Thu, 2014-04-17 at 12:22 +0100, Julien Grall wrote:
>> On 04/17/2014 12:15 PM, Jan Beulich wrote:
>>>>>> On 17.04.14 at 12:36, <julien.grall@linaro.org> wrote:
>>>> In Linux case, they are safe because they are using a single linked list.
>>>
>>> And is there a strong reason for us to use a doubly linked one?
>>
>> My first version was single-linked list... Ian asked me to use generic
>> list on V1 to avoid open code.
> 
> I also suggested that you could import a single linked list
> implementation if you thought it would be better.
> 
>> I was looking to port llist.h from Linux but it seems a bit overkill for
>> action list.
> 
> I don't see why. I'm sure there are other potential uses of singly
> linked lists which people just used a double list because it was simpler
> at the time.


They are using xchg and AFAIU it's not possible to delete an element
anywhere in the list. See:

http://lxr.free-electrons.com/source/include/linux/llist.h

-- 
Julien Grall