Re: [PATCH 4/8] sched: Update NUMA hinting faults once per scan

[Peter Zijlstra]

On Fri, Jun 28, 2013 at 12:02:33PM +0530, Srikar Dronamraju wrote:
> * Mel Gorman <mgorman@xxxxxxx> [2013-06-26 15:38:03]:
> > @@ -831,9 +837,13 @@ void task_numa_fault(int node, int pages, bool migrated)
> >  	if (unlikely(!p->numa_faults)) {
> >  		int size = sizeof(*p->numa_faults) * nr_node_ids;
> >  
> > -		p->numa_faults = kzalloc(size, GFP_KERNEL);
> > +		/* numa_faults and numa_faults_buffer share the allocation */
> > +		p->numa_faults = kzalloc(size * 2, GFP_KERNEL);
> 
> Instead of allocating buffer to hold the current faults, cant we pass
> the nr of pages and node information (and probably migrate) to
> task_numa_placement()?.

I'm afraid I don't get your question; there's more storage required than
just the arguments.

> Why should task_struct be passed as an argument to  task_numa_placement().
> It seems it always will be current.

Customary for parts -- motivated by the fact that usage of current
is/can be more expensive than passing an argument.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/