Re: sched: hang in migrate_swap

[Peter Zijlstra]

On Tue, Feb 25, 2014 at 12:47:01PM +0800, Michael wang wrote:
> On 02/24/2014 09:10 PM, Peter Zijlstra wrote:
> > On Mon, Feb 24, 2014 at 01:12:18PM +0100, Peter Zijlstra wrote:
> >> +		if (p) {
> >> +			if (unlikely(p == RETRY_TASK))
> >> +				goto again;
> > 
> > We could even make that: unlikely(p & 1), I think most CPUs can encode
> > that far better than the full pointer immediate.
> 
> Agree, unless odd-align stuff appeared...

That shouldn't happen; we rely on u32 alignment all over the place. So
for general objects we should have at least the lower two bits free to
play with.
--
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/