Re: [PATCH v10 4/4] ipc: Add a cyclic mode for id generation

[Waiman Long]

On 11/06/2018 08:02 AM, Matthew Wilcox wrote:
> On Mon, Nov 05, 2018 at 10:43:46AM -0500, Waiman Long wrote:
>> The idea of using the cyclic mode to reduce id reuse came from Manfred
>> Spraul <manfred@xxxxxxxxxxxxxxxx>. There may be a little bit of
>> additional memory/performance overhead in doing cyclic id allocation,
>> but it is a slow path anyway and a bit of overhead shouldn't be an issue.
>>
>> This patch differs from his as the cyclic mode is not the default and
>> has to be explicitly opted in for users who want that.
> I really don't like the "make the sysadmin choose" approach.  It's
> shifting blame to someone who has no idea what the tradeoffs are.
> We should try to get it right rather than force more people to learn
> why we're incapable of making the right decision for them.
>
My patch is conservative as there will be no behavior change by default.
I won't mind changing the default to cyclic if we all agree.

Cheers,
Longman