Messages in this thread | | | Date | Wed, 7 Sep 2005 08:58:18 -0600 | From | Grant Grundler <> | Subject | Re: [PATCH 1/2] pci: Block config access during BIST (resend) |
| |
On Wed, Sep 07, 2005 at 03:49:37PM +1000, Paul Mackerras wrote: > Maybe, but it seems like a bad idea to me. It's longer, it's less > obvious what's happening,
I would argue it more obvious. People looking at the code are immediately going to realize it was a deliberate choice to not use a spinlock.
> and it precludes the sorts of optimization > that we do on ppc64 where a cpu that is waiting for a lock can tell > give its time slice to the cpu that is holding the lock (on systems > where the hypervisor time-slices multiple virtual cpus on one physical > cpu).
relax_cpu() doesn't do that?
> What's wrong with just doing spin_lock/spin_unlock?
it's not wrong - just misleading IMHO. There is no "critical section" in that particular chunk of code.
If relax_cpu doesn't allow time-slice donation, then I guess spinlock/unlock with only a comment inside it explain why would be ok too.
thanks, grant - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |