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RE: [PATCH v3 03/17] xen/arm: implement node distance helpers for Arm
- To: Jan Beulich <jbeulich@xxxxxxxx>
- From: Henry Wang <Henry.Wang@xxxxxxx>
- Date: Mon, 24 Apr 2023 07:50:25 +0000
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- Thread-topic: [PATCH v3 03/17] xen/arm: implement node distance helpers for Arm
Hi Jan,
> -----Original Message-----
> From: Jan Beulich <jbeulich@xxxxxxxx>
> Subject: Re: [PATCH v3 03/17] xen/arm: implement node distance helpers for
> Arm
>
> > Thanks for the explanation! I think I now understand :) Would this diff
> below
> > look good to you then? Appreciate your patience.
>
> Looks largely okay, but possibly one part can now be omitted (see below).
>
> > unsigned char __node_distance(nodeid_t from, nodeid_t to)
> > {
> > - /* When NUMA is off, any distance will be treated as remote. */
> > + if ( from == to )
> > + return NUMA_LOCAL_DISTANCE;
> > +
> > + /* When NUMA is off, any distance will be treated as unreachable
> > (0xFF).
> */
>
> Please avoid mentioning the actual value of 0xFF: This serves no real
> purpose (afaict) and is liable to go stale at some point.
Good point, I will drop the 0xFF.
>
> > if ( numa_disabled() )
> > - return NUMA_REMOTE_DISTANCE;
> > + return NUMA_NO_DISTANCE;
>
> With the code below this is now only an optimization. Might be worth
> saying so in the comment (assuming having this optimization is deemed
> worth it).
Sounds good, if you think below comment makes sense to you, I will add:
"When NUMA is disabled, the node distance should always be
NUMA_NO_DISTANCE, directly return here as an optimization."
Kind regards,
Henry
>
> Jan
|
