On 10/14/2013 01:33 PM, Peter Zijlstra wrote:
> On Mon, Oct 14, 2013 at 12:43:35PM +0200, Juri Lelli wrote:
>> +static void replenish_dl_entity(struct sched_dl_entity *dl_se)
>> +{
>> + struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
>> + struct rq *rq = rq_of_dl_rq(dl_rq);
>> +
>> + /*
>> + * We keep moving the deadline away until we get some
>> + * available runtime for the entity. This ensures correct
>> + * handling of situations where the runtime overrun is
>> + * arbitrary large.
>> + */
>> + while (dl_se->runtime <= 0) {
>> + dl_se->deadline += dl_se->dl_deadline;
>> + dl_se->runtime += dl_se->dl_runtime;
>> + }
>
> Are we sure GCC won't be 'smart' and bite us; that is do we need
> something like:
>
> asm("" : "+rm" (dl_se->runtime));
>
> in there? See:
>
> 0d98bb2656e9 sched: Prevent compiler from optimising the sched_avg_update()
> loop
>
When disassembled everything seems fine, at least for x86 and ARM. Do I add the
fake data hazard anyway?
Thanks,
- Juri
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