Re: [RESEND PATCH 0/11] kernel:lockdep:replace DFS with BFS

[Peter Zijlstra]

On Sun, 2009-06-28 at 23:04 +0800, tom.leiming@xxxxxxxxx wrote:
> Hi,Peter
> 
> Currently lockdep uses recursion DFS(depth-first search) algorithm to
> search target in checking lock circle(check_noncircular()),irq-safe
> -> irq-unsafe(check_irq_usage()) and irq inversion when adding a new
> lock dependency. This patches replace the current DFS with BFS, based on
> the following consideration:
> 
>     1,no loss of efficiency, no matter DFS or BFS, the running time
>     are O(V+E) (V is vertex count, and E is edge count of one
>     graph);

I'd still like to get some feedback on the loss of that generation count
optimization done by DaveM, I haven't had time to analyze the
ramifications of that.

--
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/