Re: [PATCH 3/4]percpu_counter: fix code for 32bit systems

From: tj@xxxxxxxxxx
Date: Wed Apr 13 2011 - 00:00:30 EST


Hello,

On Wed, Apr 13, 2011 at 05:53:40AM +0200, Eric Dumazet wrote:
> Le mercredi 13 avril 2011 à 11:03 +0800, Shaohua Li a écrit :
> > I can do this, but please give a reason. If network code is the only
> > place requiring disable irq, why not network code do it?
>
> Lot of percpu_counter users dont use full s64 range, but "unsigned long"
> or "unsigned int". Adding a lock on 32bit arches to get the s64, then
> truncate it is not needed.

Yeah, it might hurt 32bit archs a bit but if 64bit becomes better I'll
take that any day. Also, atomic64_t implementation on x86-32 seems
pretty good and doesn't depend on irq spinlocks (which is quite
expensive), so it shouldn't be too bad.

Thanks.

--
tejun
--
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/