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| author | Santiago Leon <santil@linux.vnet.ibm.com> | 2010-09-03 20:28:41 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-09-07 03:21:49 +0200 |
| commit | 0c26b6775f36ce447722e8752bc3a006ec832df3 (patch) | |
| tree | 7c8a4b5b268fd3898d9f008c0aa38882e0ae32cc /drivers/net/ibmveth.c | |
| parent | ibmveth: Add scatter-gather support (diff) | |
| download | linux-0c26b6775f36ce447722e8752bc3a006ec832df3.tar.xz linux-0c26b6775f36ce447722e8752bc3a006ec832df3.zip | |
ibmveth: Add optional flush of rx buffer
On some machines we can improve the bandwidth by ensuring rx buffers are
not in the cache. Add a module option that is disabled by default that flushes
rx buffers on insertion.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Santiago Leon <santil@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ibmveth.c')
| -rw-r--r-- | drivers/net/ibmveth.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/net/ibmveth.c b/drivers/net/ibmveth.c index d8a89846c6a8..1685e230a389 100644 --- a/drivers/net/ibmveth.c +++ b/drivers/net/ibmveth.c @@ -127,6 +127,10 @@ module_param(rx_copybreak, uint, 0644); MODULE_PARM_DESC(rx_copybreak, "Maximum size of packet that is copied to a new buffer on receive"); +static unsigned int rx_flush __read_mostly = 0; +module_param(rx_flush, uint, 0644); +MODULE_PARM_DESC(rx_flush, "Flush receive buffers before use"); + struct ibmveth_stat { char name[ETH_GSTRING_LEN]; int offset; @@ -234,6 +238,14 @@ static int ibmveth_alloc_buffer_pool(struct ibmveth_buff_pool *pool) return 0; } +static inline void ibmveth_flush_buffer(void *addr, unsigned long length) +{ + unsigned long offset; + + for (offset = 0; offset < length; offset += SMP_CACHE_BYTES) + asm("dcbfl %0,%1" :: "b" (addr), "r" (offset)); +} + /* replenish the buffers for a pool. note that we don't need to * skb_reserve these since they are used for incoming... */ @@ -286,6 +298,12 @@ static void ibmveth_replenish_buffer_pool(struct ibmveth_adapter *adapter, struc desc.fields.flags_len = IBMVETH_BUF_VALID | pool->buff_size; desc.fields.address = dma_addr; + if (rx_flush) { + unsigned int len = min(pool->buff_size, + adapter->netdev->mtu + + IBMVETH_BUFF_OH); + ibmveth_flush_buffer(skb->data, len); + } lpar_rc = h_add_logical_lan_buffer(adapter->vdev->unit_address, desc.desc); if (lpar_rc != H_SUCCESS) @@ -1095,6 +1113,9 @@ static int ibmveth_poll(struct napi_struct *napi, int budget) skb_copy_to_linear_data(new_skb, skb->data + offset, length); + if (rx_flush) + ibmveth_flush_buffer(skb->data, + length + offset); skb = new_skb; ibmveth_rxq_recycle_buffer(adapter); } else { |