Satoshi OSHIMA <[EMAIL PROTECTED]> writes: > This patch introduces global variable for UDP memory accounting. > The unit is page.
The global variable doesn't seem to be very MP scalable, especially if you change it for each packet. This will be a very hot cache line, in the worst case bouncing around a large machine. Possible alternatives: - Per CPU variables - You only change the global on socket creation time (by pre allocating a large amount) or when the system comes under memory pressure. - Batching of the global updates for multiple packets [that's a variant of the previous one, might be still too costly though] Also for such variables it's usually good to cache line pad them on SMP to avoid false sharing with something else. -Andi - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
