Re: [patch 04/20] ibmveth: Add tx_copybreak

Use the existing bounce buffer if we send a buffer under a certain size.
This saves the overhead of a TCE map/unmap.

I can't see any reason for the wmb() in the bounce buffer case, if we need
a barrier it will be before we call h_send_logical_lan but we have
nothing in the common case. Remove it.

Signed-off-by: Anton Blanchard <redacted>
---

Index: powerpc.git/drivers/net/ibmveth.c
===================================================================

--- powerpc.git.orig/drivers/net/ibmveth.c	2010-08-10 18:35:52.293272470 +1000
+++ powerpc.git/drivers/net/ibmveth.c	2010-08-10 18:35:55.440741255 +1000

@@ -117,6 +117,11 @@ MODULE_DESCRIPTION("IBM i/pSeries Virtua
 MODULE_LICENSE("GPL");
 MODULE_VERSION(ibmveth_driver_version);

+static unsigned int tx_copybreak __read_mostly = 128;