Re: [Fwd: Re: 3w-9xxx status in kernel]

From: Martin Honermeyer
Date: Wed Apr 19 2006 - 08:02:31 EST


Arjan van de Ven wrote:

> -------- Forwarded Message --------
>> From: Martin Honermeyer <maze@xxxxxxxxxxxxxxxxx>
>> To: linux-kernel@xxxxxxxxxxxxxxx
>> Subject: Re: 3w-9xxx status in kernel
>> Date: Wed, 19 Apr 2006 13:02:42 +0200
>>
>> Hi,
>>
>> same problem over here. Why does the newest kernel contain an old version
>> of the 3w-9xxx driver?
>
> because nobody bothered to submit it??

Okay, now I know how it works.

>
>>
>> We are having performance problems using a 9550SX controller. Read
>> throughput (measured with hdparm)
>
> hdparm is not a good measurement tool at all for performance.
> At least use something like tiobench (tiobench.sf.net)

Thanks for the hint. Here is tiobench output:

$ tiobench
No size specified, using 2000 MB
Run #1: /usr/bin/tiotest -t 8 -f 250 -r 500 -b 4096 -d . -TTT


Unit information
================
File size = megabytes
Blk Size = bytes
Rate = megabytes per second
CPU% = percentage of CPU used during the test
Latency = milliseconds
Lat% = percent of requests that took longer than X seconds
CPU Eff = Rate divided by CPU% - throughput per cpu load

Sequential Reads
File Blk Num Avg
Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency
Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ ---------
----------- -------- -------- -----
2.6.15-19-amd64-xeon 2000 4096 1 46.63 7.159% 0.083
484.49 0.00000 0.00000 651
2.6.15-19-amd64-xeon 2000 4096 2 34.65 10.11% 0.223
386.04 0.00000 0.00000 343
2.6.15-19-amd64-xeon 2000 4096 4 15.14 8.629% 1.016
1128.07 0.00000 0.00000 175
2.6.15-19-amd64-xeon 2000 4096 8 23.56 23.09% 1.209
2051.28 0.00020 0.00000 102

Random Reads
File Blk Num Avg
Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency
Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ ---------
----------- -------- -------- -----
2.6.15-19-amd64-xeon 2000 4096 1 3.76 0.626% 1.037
99.77 0.00000 0.00000 601
2.6.15-19-amd64-xeon 2000 4096 2 4.88 1.654% 1.545
97.82 0.00000 0.00000 295
2.6.15-19-amd64-xeon 2000 4096 4 5.40 3.389% 2.673
208.84 0.00000 0.00000 159
2.6.15-19-amd64-xeon 2000 4096 8 6.51 11.20% 4.013
261.38 0.00000 0.00000 58

Sequential Writes
File Blk Num Avg
Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency
Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ ---------
----------- -------- -------- -----
2.6.15-19-amd64-xeon 2000 4096 1 13.05 6.946% 0.274
34488.77 0.00098 0.00039 188
2.6.15-19-amd64-xeon 2000 4096 2 6.99 14.91% 0.432
57601.25 0.00352 0.00039 47
2.6.15-19-amd64-xeon 2000 4096 4 7.10 53.92% 1.360
69873.41 0.00957 0.00176 13
2.6.15-19-amd64-xeon 2000 4096 8 7.07 78.44% 2.813
71698.67 0.02441 0.00684 9

Random Writes
File Blk Num Avg
Maximum Lat% Lat% CPU
Identifier Size Size Thr Rate (CPU%) Latency
Latency >2s >10s Eff
---------------------------- ------ ----- --- ------ ------ ---------
----------- -------- -------- -----
2.6.15-19-amd64-xeon 2000 4096 1 0.44 0.142% 0.010
11.50 0.00000 0.00000 306
2.6.15-19-amd64-xeon 2000 4096 2 0.43 0.324% 0.009
0.07 0.00000 0.00000 131
2.6.15-19-amd64-xeon 2000 4096 4 0.42 1.979% 0.031
0.50 0.00000 0.00000 21
2.6.15-19-amd64-xeon 2000 4096 8 0.41 4.640% 0.077
1.33 0.00000 0.00000 9


I am especially scared of the high CPU usage in sequential writes! Btw: this
server sits idle at the moment. Just some webserver processes running!

Specs:
Dual-Xeon 3 GHz, Ubuntu Dapper 64bit with 2.6.15 Ubuntu kernel.


Martin


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