Re: [tip:core/locking 2/3] lockdep:define preallocated "stack" for BFS as per cpu variable

From: Ming Lei
Date: Wed Jul 22 2009 - 09:10:59 EST


2009/7/22 Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>:
> On Wed, 2009-07-22 at 20:58 +0800, tom.leiming@xxxxxxxxx wrote:
>> From: Ming Lei <tom.leiming@xxxxxxxxx>
>
> This patch can use a changelog.
>
> Why is this needed, isn't all that serialized by the graph_lock anyway?
> Or are there a few paths where this isn't the case and we're now racy?

It is really serialized by the graph_lock, but we can prevent cpu cache from
being flushing by different cpu access, which seems that can be avoided by
per cpu variables. Right?

Thanks.

--
Lei Ming
--
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/