Re: b44: regression in 2.6.22 (resend)

Michael Buesch
2007-05-27T21:14:40Z

On Sunday 27 May 2007 21:25:17 Maximilian Engelhardt wrote:
> 2.6.21.1:
> [ 5] local 192.168.1.2 port 58414 connected with 192.168.1.1 port 5001
> [ 5] 0.0-60.6 sec 1.13 MBytes 157 Kbits/sec
> [ 4] local 192.168.1.2 port 5001 connected with 192.168.1.1 port 57837
> [ 4] 0.0-63.1 sec 2.82 MBytes 375 Kbits/sec

> 2.6.22-rc3:
> [ 5] local 192.168.1.2 port 46557 connected with 192.168.1.1 port 5001
> [ 5] 0.0-60.4 sec 58.9 MBytes 8.18 Mbits/sec
> [ 4] local 192.168.1.2 port 5001 connected with 192.168.1.1 port 51633
> [ 4] 0.0-63.1 sec 7.27 MBytes 967 Kbits/sec

This is the diff between these two kernels.
I'm not sure why you see a much better TX throughput here.

Can you re-check to make sure it's not just some test-jitter?

--- linux-2.6.21.1/drivers/net/b44.c 2007-05-27 22:58:01.000000000 +0200
+++ linux-2.6.22-rc3/drivers/net/b44.c 2007-05-27 23:01:44.000000000 +0200
@@ -825,12 +825,11 @@
if (copy_skb == NULL)
goto drop_it_no_recycle;

- copy_skb->dev = bp->dev;
skb_reserve(copy_skb, 2);
skb_put(copy_skb, len);
/* DMA sync done above, copy just the actual packet */
- memcpy(copy_skb->data, skb->data+bp->rx_offset, len);
-
+ skb_copy_from_linear_data_offset(skb, bp->rx_offset,
+ copy_skb->data, len);
skb = copy_skb;
}
skb->ip_summed = CHECKSUM_NONE;
@@ -1007,7 +1006,8 @@
goto err_out;
}

- memcpy(skb_put(bounce_skb, len), skb->data, skb->len);
+ skb_copy_from_linear_data(skb, skb_put(bounce_skb, len),
+ skb->len);
dev_kfree_skb_any(skb);
skb = bounce_skb;
}

--
Greetings Michael.