Re: RFC: Boiler plate functions for ida / idr allocation?

From: Jonathan Cameron
Date: Fri Jul 22 2011 - 12:43:40 EST

On 07/22/11 12:13, Rusty Russell wrote:
> On Thu, 21 Jul 2011 10:35:01 +0200, Tejun Heo <tj@xxxxxxxxxx> wrote:
>> On Thu, Jul 21, 2011 at 10:19:46AM +0200, Tejun Heo wrote:
>>> On Thu, Jul 21, 2011 at 05:07:36PM +0930, Rusty Russell wrote:
>>>> From: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
>>>> Subject: ida: Simplified functions for id allocation.
>>>> The current hyper-optimized functions are overkill if you simply want
>>>> to allocate an id for a device. Create versions which use an internal
>>>> lock.
>>>> Thanks to Tejun for feedback. Feel free to delete the #ifdef TEST
>>>> code.
>>>> Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
>>> ...
>>>> static struct kmem_cache *idr_layer_cache;
>>>> +static DEFINE_SPINLOCK(simple_ida);
>>> I think the name is a bit confusing. Maybe simple_ida_lock is better?
>>> Other than that,
>> Ooh, one more thing, maybe it would be better to use spin_lock_irq()
>> to allow calling free under other irq locks.
> Jonathan, please take original patch and mod it to taste, and produce a
> series on it you can push to Andrew.
> As for irqsave etc, as soon as someone needs that we can add
> it... Jonathan will run into it soon enough.
> Thanks,
> Rusty.
Given the timing, it's clearly 3.2 merge window material anyway. Too late to
push any users this time round even if we hustled it through.

Quite a few 'interesting' users out there now I look into them. Might take
a little while to get them past the relevant maintainers.

I've just sent out a few of the simpler cases. I guess Andrew may take the core
patch and the others will route through relevant subsystems.

A few more to do. Some of them need a little more thought.

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