Re: [PATCH 1/6] ehea: interface to network stack

On Sat, 12 August 2006 06:56:24 +1000, Anton Blanchard wrote:

quoted

+
+				skb_index = ((index - i
+					      + port_res->skb_arr_sq_len)
+					     % port_res->skb_arr_sq_len);

This is going to force an expensive divide. Its much better to change
this to the simpler and quicker:

i++;
if (i > max)
	i = 0;

Is a conditional cheaper than a divide?  In case of a misprediction I
would assume it to be significantly slower and I don't know the ratio
of mispredictions for this branch.

Jörn

-- 
Victory in war is not repetitious.
-- Sun Tzu