* 2.5.xx kernel performance issue...
@ 2002-10-25 13:11 Pavan Kumar Reddy N.S.
2002-10-25 17:20 ` David S. Miller
0 siblings, 1 reply; 2+ messages in thread
From: Pavan Kumar Reddy N.S. @ 2002-10-25 13:11 UTC (permalink / raw)
To: 'Linux-Kernel'
[-- Attachment #1: Type: text/plain, Size: 7232 bytes --]
Hi All,
Here is the summary of LMBench(patch2) performance tool results for
different Linux kernels.
There are some surprising results for 2.5.XX kernel.
There is a drastic change in the latency of system calls stat and
open/close between 2.5.xx kernels.
Local communication latencies have also increased for 2.5.44 kernel
compared to 2.5.43.
TCP and AF_UNIX socket stream bandwidth has also got drastic change.
Does any one have any idea why there is a spike in performance of 2.5.xx
kernel ??
Thanks,
pavan
========================================================================
L M B E N C H 2 . 0 [PATCH 2] S U M M A R Y
------------------------------------------------------------------------
----
Hardware Specifications:
--------------------------------------
# CPU's = 1 - Intel PIII
Motherboard = Intel 810
CPU Freq = 868 MHz
RAM = 128MB
L1 I Cache = 16K
L1 D Cache = 16K
L2 Cache = 256K
File System = ext3
glibc ver. = 2.2.5-34
eth0 = RTL8139
Processor, Processes - times in microseconds - smaller is better
------------------------------------------------------------------------
------------------------------------
OS MHz null null open selct sig
sig fork exec sh
call I/O stat close TCP
inst hndl proc proc proc
------------------------------- ----- -------- ------ ------- --------
-------- -------- -------- -------------
Linux 2.4.19 868 0.39 0.71 3.90 5.15 29.7 0.94 3.03 143.
734. 5051
Lin 2.4.20-pre11 868 0.39 0.70 3.84 5.08 32.4 0.94 3.03 154.
734. 5059
Linux 2.5.42 868 0.39 0.76 24.6 26.1 32.1 1.01 4.89 361.
1592 7710
Linux 2.5.43 868 0.39 0.75 4.38 5.53 28.9 1.02 3.32 348.
1284 6335
Linux 2.5.44 868 0.39 0.77 24.5 26.1 32.5 1.02 4.89 433.
1587 7634
------------------------------------------------------------------------
------------------------------------
Context switching - times in microseconds - smaller is better
------------------------------------------------------------------------
------------------------------------
OS 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K
16p/16K 16p/64K
ctxsw ctxsw ctxsw ctxsw
ctxsw ctxsw ctxsw
------------------------------ ----------- ----------- ------------
--------------- ----------- ---------------
Linux 2.4.19 1.100 4.3700 13.2 7.3000 181.1
47.6 182.6
Lin 2.4.20-pre11 1.090 4.4000 13.2 9.9000 182.3 46.1
182.9
Linux 2.5.42 1.170 4.5100 13.2 7.4300 187.4
44.7 189.3
Linux 2.5.43 1.250 4.3000 13.2 6.9600 187.9
43.3 188.2
Linux 2.5.44 1.140 4.4000 13.2 7.0200 188.5
43.0 189.2
------------------------------------------------------------------------
-------------------------------------
*Local* Communication latencies in microseconds - smaller is better
------------------------------------------------------------------------
------------------------------------
OS 2p/0K Pipe AF UDP RPC/ TCP
RPC/ TCP
ctxsw UNIX
UDP TCP conn
------------------------------- ---------- ---------- ----------
---------- ----------- --------- ------------
Linux 2.4.19 1.120 6.236 11.2 16.5 37.3 24.1
49.9 83.2
Lin 2.4.20-pre11 1.090 6.426 11.3 18.6 39.7 25.3
52.1 86.1
Linux 2.5.42 1.170 6.913 19.2 28.1 52.4 113.6
145.7 146.
Linux 2.5.43 1.250 6.876 12.9 20.7 42.3 29.5
56.2 94.1
Linux 2.5.44 1.140 6.928 19.6 31.1 55.3 113.7
145.4 142.
------------------------------------------------------------------------
-------------------------------------
File & VM system latencies in microseconds - smaller is better
------------------------------------------------------------------------
------------------------------------
OS 0K File 10K File
Mmap Prot Page
Create Delete Create Delete Latency
Fault Fault
------------------------------- ----------------------
----------------------- ------------- --------------
Linux 2.4.19 70.8 23.6 235.4 48.4 274.0 0.780
3.00000
Lin 2.4.20-pre11 71.2 25.3 239.8 49.9 269.0 0.784
3.00000
Linux 2.5.42 98.4 52.6 298.4 87.9 511.0 0.972
4.00000
Linux 2.5.43 72.7 26.4 249.1 56.0 505.0 0.917
4.00000
Linux 2.5.44 98.5 53.4 295.2 88.3 503.0 0.956
4.00000
------------------------------------------------------------------------
-----------------------------------
*Local* Communication bandwidths in MB/s - bigger is better
------------------------------------------------------------------------
------------------------------------------------
OS Pipe AF TCP File Mmap
Bcopy Bcopy Mem Mem
UNIX reread
reread (libc) (hand) read write
------------------------------- ------- ----------- --------
-------------- ------------- ----------- ----------- ---------
Linux 2.4.19 715. 604. 152. 317.6 352.0 111.6
102.6 352. 141.4
Lin 2.4.20-pre11 725. 449. 147. 315.7 352.1 111.6
102.5 351. 141.4
Linux 2.5.42 475. 148. 17.4 307.2 344.5 110.8
102.5 344. 139.5
Linux 2.5.43 387. 617. 38.2 298.1 345.4 111.2
102.4 345. 139.7
Linux 2.5.44 442. 147. 17.0 300.1 344.9 111.0
102.4 345. 139.6
------------------------------------------------------------------------
--------------------------------------------------
Memory latencies in nanoseconds - smaller is better
(WARNING - may not be correct, check graphs)
------------------------------------------------------------------------
-----------------
OS Mhz L1 $ L2 $ Main mem Guesses
----------------------------- -------- ----------- -------------
-------------------------
Linux 2.4.19 868 3.456 8.0640 178.1
Lin 2.4.20-pre11 868 3.456 8.0690 178.2
Linux 2.5.44 868 3.490 8.1560 181.2
Linux 2.5.43 868 3.491 8.1530 180.6
Linux 2.5.44 868 3.490 8.2170 180.4
------------------------------------------------------------------------
----------------
Note: All results are average of five iterations.
============================================
============================================
PAVAN KUMAR REDDY N.S.
Sr.Software Engineer
Wipro Technologies
53/1, Hosur road, Madivala
Bangalore - 68.
Phone Off: +91-80-5502001-8 extn: 5086.
Res: +91-80-6685179
http://www.wipro.com/linux/
============================================
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^ permalink raw reply [flat|nested] 2+ messages in thread* Re: 2.5.xx kernel performance issue...
2002-10-25 13:11 2.5.xx kernel performance issue Pavan Kumar Reddy N.S.
@ 2002-10-25 17:20 ` David S. Miller
0 siblings, 0 replies; 2+ messages in thread
From: David S. Miller @ 2002-10-25 17:20 UTC (permalink / raw)
To: Pavan Kumar Reddy N.S.; +Cc: 'Linux-Kernel'
On Fri, 2002-10-25 at 06:11, Pavan Kumar Reddy N.S. wrote:
> TCP and AF_UNIX socket stream bandwidth has also got drastic change.
There is debugging code enabled for the loopback interface
in 2.5.x to test out some new features in the networking stack.
Once that debugging code is removed (say in 2.6.0) these performance
drops will drop.
I have to post this every time someone complains about lmbench
performance loss in 2.5.x
^ permalink raw reply [flat|nested] 2+ messages in thread
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