From: Thomas Graf <[EMAIL PROTECTED]> Date: Tue, 23 Aug 2005 19:00:54 +0200
> Setting txqlen of the device to 2*MAX_CHAINLEN should be sufficient > in most cases. We'd probably have to modify the kick/watchdog a bit > to actually get the packets out faster because the enqueue()s would > happen less frequently, would have to look into this. Oh yes, that's the other problem with this idea. Currently NETIF_F_SG drivers do not wake up the TX queue until MAX_SKB_FRAGS descriptors are ready, now they'll have to defer until (N * MAX_SKB_FRAGS) are available. And even for a low value of "N" like 3 this is a whopping _54_ TX descriptors on 4K PAGE_SIZE platforms. Heck, many drivers do not come up with that many TX descriptors available, in total! And it's unthinkable to put this TX queue emptyness knowledge into the generic queueing layer. Poor man's TSO is definitely not worth this. - 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
