Re: [PATCH] IB/mad: Use ID allocator routines to allocate agent number

From: Jason Gunthorpe
Date: Wed May 30 2018 - 18:09:49 EST


On Wed, May 30, 2018 at 10:07:16PM +0200, HÃkon Bugge wrote:
>
>
> > On 30 May 2018, at 17:10, Jason Gunthorpe <jgg@xxxxxxxx> wrote:
> >
> > On Wed, May 30, 2018 at 02:22:56PM +0200, Hans Westgaard Ry wrote:
> >
> >> We came up with this code snippet which we think handles both preventing
> >> immediate re-use and too big/wrapping...
> >
> > Isn't this basically the same as idr_alloc_cyclic ?
>
> I draw my statement back. The idr_alloc_cyclic() is the family of idr's that associates a pointer with the bit. Hence, each bit is a bit + 64b.
>
> That's why we ended up with Hans' pseudo code.

Okay, fair enough.

Is it worth adding a ida_get_new_cyclic for this?

Jason