Lmbench performance drop 2.6.18-->2.6.27
From: Ajay Patel
Date: Thu Nov 19 2009 - 16:13:24 EST
Hi all,
Part of our evaluation to upgrade kernel we
ran lmbench. The lmbench results shows significant performance
drop from 2.6.18 to 2.6.27. (Results attached)
The benchmark was performed on same hardware with
different distro. (Quad-Core AMD Opteron(tm) Processor 2346 HE,
cpu MHz : 1795.597, cache size : 512 KB, x86_64 kernel)
The 2.6.18 based distribution was from CentOS release 5.4.
(Linux cento-5.4 2.6.18-164.el5).
The 2.6.27 based distribution was from FC10.
(Fedora Core release 10 2.6.27.5-117.fc10-x86_64).
Does this results make sense? Is this expected?
Am I doing something wrong?
Thanks
Ajay
L M B E N C H 3 . 0 S U M M A R Y
------------------------------------
(Alpha software, do not distribute)
Basic system parameters
------------------------------------------------------------------------------
Host OS Description Mhz tlb cache mem scal
pages line par load
bytes
--------- ------------- ----------------------- ---- ----- ----- ------ ----
cento-5.4 Linux 2.6.18- x86_64-linux-gnu 1797 48 64 1.0200 1
cento-5.4 Linux 2.6.18- x86_64-linux-gnu 1797 48 64 1.0200 1
cento-5.4 Linux 2.6.18- x86_64-linux-gnu 1797 48 64 1.0200 1
fedora-10 Linux 2.6.27. x86_64-linux-gnu 1791 48 64 5.4100 1
fedora-10 Linux 2.6.27. x86_64-linux-gnu 1791 48 64 5.4400 1
fedora-10 Linux 2.6.27. x86_64-linux-gnu 1791 48 64 5.4400 1
Processor, Processes - times in microseconds - smaller is better
------------------------------------------------------------------------------
Host OS Mhz null null open slct sig sig fork exec sh
call I/O stat clos TCP inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
cento-5.4 Linux 2.6.18- 1797 0.24 0.33 2.31 3.01 5.14 0.36 1.36 195. 611. 2444
cento-5.4 Linux 2.6.18- 1797 0.24 0.34 2.17 3.21 5.27 0.36 1.46 186. 616. 2466
cento-5.4 Linux 2.6.18- 1797 0.24 0.33 2.26 3.25 5.08 0.38 1.36 195. 595. 2294
fedora-10 Linux 2.6.27. 1791 0.24 0.39 3.60 5.08 4.37 0.37 1.66 228. 847. 3077
fedora-10 Linux 2.6.27. 1791 0.24 0.39 3.40 5.06 4.38 0.37 1.64 227. 843. 2977
fedora-10 Linux 2.6.27. 1791 0.24 0.40 3.50 4.98 4.33 0.37 1.61 218. 841. 2996
Basic integer operations - times in nanoseconds - smaller is better
-------------------------------------------------------------------
Host OS intgr intgr intgr intgr intgr
bit add mul div mod
--------- ------------- ------ ------ ------ ------ ------
cento-5.4 Linux 2.6.18- 0.5700 0.5600 0.2000 28.7 16.4
cento-5.4 Linux 2.6.18- 0.5600 0.5600 0.2000 28.5 16.3
cento-5.4 Linux 2.6.18- 0.5700 0.5600 0.2000 28.7 16.3
fedora-10 Linux 2.6.27. 0.5700 0.5700 0.2300 28.8 16.4
fedora-10 Linux 2.6.27. 0.5700 0.5600 0.2300 28.8 16.4
fedora-10 Linux 2.6.27. 0.5700 0.5600 0.2300 28.8 16.4
Basic uint64 operations - times in nanoseconds - smaller is better
------------------------------------------------------------------
Host OS int64 int64 int64 int64 int64
bit add mul div mod
--------- ------------- ------ ------ ------ ------ ------
cento-5.4 Linux 2.6.18- 0.570 0.2500 43.4 45.1
cento-5.4 Linux 2.6.18- 0.560 0.2500 43.4 44.8
cento-5.4 Linux 2.6.18- 0.560 0.2500 43.4 45.0
fedora-10 Linux 2.6.27. 0.570 0.2500 43.5 45.2
fedora-10 Linux 2.6.27. 0.570 0.2500 43.5 45.2
fedora-10 Linux 2.6.27. 0.570 0.2500 43.5 45.2
Basic float operations - times in nanoseconds - smaller is better
-----------------------------------------------------------------
Host OS float float float float
add mul div bogo
--------- ------------- ------ ------ ------ ------
cento-5.4 Linux 2.6.18- 2.2500 2.2800 10.6 7.3500
cento-5.4 Linux 2.6.18- 2.2500 2.2700 10.5 7.3300
cento-5.4 Linux 2.6.18- 2.2500 2.2800 10.5 7.3400
fedora-10 Linux 2.6.27. 2.2600 2.2900 10.6 7.3600
fedora-10 Linux 2.6.27. 2.2600 2.2900 10.6 7.3600
fedora-10 Linux 2.6.27. 2.2600 2.2900 10.6 7.3700
Basic double operations - times in nanoseconds - smaller is better
------------------------------------------------------------------
Host OS double double double double
add mul div bogo
--------- ------------- ------ ------ ------ ------
cento-5.4 Linux 2.6.18- 2.2500 2.2800 12.8 9.6100
cento-5.4 Linux 2.6.18- 2.2400 2.2800 12.7 9.5300
cento-5.4 Linux 2.6.18- 2.2500 2.2800 12.8 9.5900
fedora-10 Linux 2.6.27. 2.2600 2.2900 12.8 9.6200
fedora-10 Linux 2.6.27. 2.2600 2.2900 12.8 9.6200
fedora-10 Linux 2.6.27. 2.2600 2.2900 12.8 9.6200
Context switching - times in microseconds - smaller is better
-------------------------------------------------------------------------
Host OS 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K
ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw
--------- ------------- ------ ------ ------ ------ ------ ------- -------
cento-5.4 Linux 2.6.18- 0.9500 4.7300 8.3600 4.3700 8.2400 5.13000 12.6
cento-5.4 Linux 2.6.18- 0.8700 3.0300 5.3900 4.9400 8.4100 4.82000 12.8
cento-5.4 Linux 2.6.18- 0.9400 3.7100 7.1400 4.3200 7.5600 4.66000 10.7
fedora-10 Linux 2.6.27. 7.5300 2.5800 11.2 5.9300 9.9500 5.10000 15.0
fedora-10 Linux 2.6.27. 7.2400 2.4400 3.4600 6.1300 8.9000 7.19000 13.1
fedora-10 Linux 2.6.27. 7.4200 7.4500 11.4 4.8600 9.6700 5.43000 9.42000
*Local* Communication latencies in microseconds - smaller is better
---------------------------------------------------------------------
Host OS 2p/0K Pipe AF UDP RPC/ TCP RPC/ TCP
ctxsw UNIX UDP TCP conn
--------- ------------- ----- ----- ---- ----- ----- ----- ----- ----
cento-5.4 Linux 2.6.18- 0.950 6.480 6.87 20.0 21.1 19.3 23.8 27.
cento-5.4 Linux 2.6.18- 0.870 9.939 9.61 20.3 24.0 18.8 26.8 27.
cento-5.4 Linux 2.6.18- 0.940 11.7 6.96 20.4 21.3 21.7 25.0 29.
fedora-10 Linux 2.6.27. 7.530 7.751 9.56 34.6 39.5 36.1 47.6 59.
fedora-10 Linux 2.6.27. 7.240 7.733 9.16 34.5 24.6 41.0 32.5 110.
fedora-10 Linux 2.6.27. 7.420 7.648 9.35 18.2 39.9 40.3 47.9 58.
File & VM system latencies in microseconds - smaller is better
-------------------------------------------------------------------------------
Host OS 0K File 10K File Mmap Prot Page 100fd
Create Delete Create Delete Latency Fault Fault selct
--------- ------------- ------ ------ ------ ------ ------- ----- ------- -----
cento-5.4 Linux 2.6.18- 15.8 9.5580 47.9 21.2 5150.0 0.416 1.60530 2.484
cento-5.4 Linux 2.6.18- 15.7 9.8031 48.5 21.4 4916.0 0.281 1.65810 2.503
cento-5.4 Linux 2.6.18- 15.9 9.4592 48.9 21.1 5139.0 0.394 1.47310 2.435
fedora-10 Linux 2.6.27. 61.5 13.9 103.5 28.1 6162.0 0.477 1.66810 2.297
fedora-10 Linux 2.6.27. 63.5 13.9 111.6 29.0 6103.0 0.384 1.75870 2.305
fedora-10 Linux 2.6.27. 62.2 14.1 110.6 29.2 6344.0 0.459 1.79540 2.297
*Local* Communication bandwidths in MB/s - bigger is better
-----------------------------------------------------------------------------
Host OS Pipe AF TCP File Mmap Bcopy Bcopy Mem Mem
UNIX reread reread (libc) (hand) read write
--------- ------------- ---- ---- ---- ------ ------ ------ ------ ---- -----
cento-5.4 Linux 2.6.18- 1887 1202 946. 1678.9 2952.1 1473.7 1400.5 2425 1409.
cento-5.4 Linux 2.6.18- 1337 1195 940. 1700.9 3027.9 1477.5 1400.7 2423 1368.
cento-5.4 Linux 2.6.18- 781. 1098 864. 1715.8 3011.9 1202.8 1408.5 2190 1410.
fedora-10 Linux 2.6.27. 1604 1181 923. 1541.7 2666.6 1447.8 1342.4 2429 1408.
fedora-10 Linux 2.6.27. 1592 1782 925. 1590.7 2886.1 1432.6 1391.9 2430 1401.
fedora-10 Linux 2.6.27. 1606 1170 926. 1550.8 2640.2 1432.3 1354.4 2429 1406.
Memory latencies in nanoseconds - smaller is better
(WARNING - may not be correct, check graphs)
------------------------------------------------------------------------------
Host OS Mhz L1 $ L2 $ Main mem Rand mem Guesses
--------- ------------- --- ---- ---- -------- -------- -------
cento-5.4 Linux 2.6.18- 1797 1.6860 8.6140 99.3 159.2
cento-5.4 Linux 2.6.18- 1797 1.6870 8.6210 99.3 155.0
cento-5.4 Linux 2.6.18- 1797 1.6810 8.6140 106.0 155.9
fedora-10 Linux 2.6.27. 1791 1.6920 8.6470 99.5 153.2
fedora-10 Linux 2.6.27. 1791 1.6920 8.6500 99.5 153.5
fedora-10 Linux 2.6.27. 1791 1.6920 8.6500 99.5 154.4