[RESEND] Implement batching skb API and support in IPoIB

Hi Dave,

I am re-sending in case you didn't get this earlier. Also sending REV5 of
the patch.
I will send patch for e1000e on monday or tuesday after making the changes
and
testing over the weekend.

thanks,

- KK

__________________

Hi Dave,

David Miller [off-list ref] wrote on 08/29/2007 10:21:50 AM:

From: Krishna Kumar2 <redacted>
Date: Wed, 29 Aug 2007 08:53:30 +0530

quoted

I am scp'ng from 192.168.1.1 to 192.168.1.2 and captured at the send
side.

Bad choice of test, this is cpu limited since the scp
has to encrypt and MAC hash all the data it sends.

Use something like straight ftp or "bw_tcp" from lmbench.

I used bw_tcp from lmbench-3. I transfered 500MB and captured
the tcpdump, and analysis at various points gave pipeline sizes:

26064, 27792, 22888, 23168, 23448, 20272, 23168, 4344, 10136,
164792, 35920, 26344, 24336, 24336, 23168, 25784, 23168,

There was one huge 164K, otherwise most were in smaller ranges
like 20-30K. I ran the following test script:

SERVER=192.168.1.2
BYTES=100m
BUFFERSIZES="4096 16384 65536 131072 262144"
PROCS="1 8"
ITERATIONS=5

for m in $BUFFERSIZES
do
      for procs in $PROCS
      do
            echo TEST: Size:$m Procs:$procs
            bw_tcp -N $ITERATIONS -m $m -M $BYTES -P $procs $SERVER
      done
done

Result is:
Test without batching:
#       Size       Procs     BW (MB/s)
1       4096       1         117.39
2       16384      1         117.49
3       65536      1         117.55
4       131072     1         117.55
5       262144     1         117.58

6       4096       8         117.18
7       16384      8         117.47
8       65536      8         117.54
9       131072     8         117.59
10      262144     8         117.55

Test with batching:
#       Size       Procs     BW (MB/s)
1       4096       1         117.39
2       16384      1         117.48
3       65536      1         117.55
4       131072     1         117.58
5       262144     1         117.58

6       4096       8         117.19
7       16384      8         117.46
8       65536      8         117.53
9       131072     8         117.55
10      262144     8         117.60

So it doesn't seem to harm e1000.

Can someone give a link to the E1000E driver? I couldn't find it
after downloading Jeff's netdev-2.6 tree.

Thanks,

- KK