From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bruce Richardson <bruce.richardson@intel.com>
Subject: Re: [PATCH 1/6] ring: change head and tail to
 pointer-width size
Date: Fri, 11 Jan 2019 10:58:48 +0000
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Cc: Gage Eads <gage.eads@intel.com>, dev@dpdk.org, olivier.matz@6wind.com,
 arybchenko@solarflare.com, konstantin.ananyev@intel.com
To: "Burakov, Anatoly" <anatoly.burakov@intel.com>
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On Fri, Jan 11, 2019 at 10:40:19AM +0000, Burakov, Anatoly wrote:
> <...>
> 
> > + * Copyright(c) 2016-2019 Intel Corporation
> >    */
> >   /**
> > @@ -88,7 +88,7 @@ rte_event_ring_enqueue_burst(struct rte_event_ring *r,
> >   		const struct rte_event *events,
> >   		unsigned int n, uint16_t *free_space)
> >   {
> > -	uint32_t prod_head, prod_next;
> > +	uintptr_t prod_head, prod_next;
> 
> I would also question the use of uinptr_t. I think semnatically, size_t is
> more appropriate.
> 
Yes, it would, but I believe in this case they want to use the largest size
of (unsigned)int where there exists an atomic for manipulating 2 of them
simultaneously. [The largest size is to minimize any chance of an ABA issue
occuring]. Therefore we need 32-bit values on 32-bit and 64-bit on 64, and
I suspect the best way to guarantee this is to use pointer-sized values. If
size_t is guaranteed across all OS's to have the same size as uintptr_t it
could also be used, though.

/Bruce