Re: LMbench results for 2.5.40

Bill Davidsen
2002-10-08T19:40:57Z

On Wed, 2 Oct 2002, Patrick Mau wrote:

> On Tue, Oct 01, 2002 at 06:16:34PM -0400, Jeff Garzik wrote:
> >
> > any chance you can run each set of tests three times? (I know it takes
> > longer, but it's better for statistical purposes...)
>
> Hallo Jeff,
>
> sorry for the late reply, I had to work all day. Below are five
> sequencial runs of lmbench with 2.4.18 and 2.5.40. Kernel 2.5 was
> compiled without CONFIG_PREEMPT.
>
> I only rebooted between kernels, not between each run.
> All numbers were obtained in single-user mode.

One thing which is pretty definite is that many of the latencies are worse
in newer kernels, and many bandwidth types are also worse. I have seen
statements that this is due to debugging code in the kernel and that it
can and will be fixed in the production versions. I sure hope that claim
is correct. I believe the same thing was said about 2.2 vs. 2.4 numbers,
and that difference hasn't gone away yet.

It's not the magnitude of the change that bothers me, but the direction.

> 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
> --------- ------------- ----- ------ ------ ------ ------ ------- -------
> tony Linux 2.4.18 0.850 1.7300 4.0600 1.8700 21.4 4.57000 29.7
> tony Linux 2.4.18 0.800 1.7200 3.9100 1.9500 23.8 4.27000 29.7
> tony Linux 2.4.18 0.860 1.6800 3.8900 1.9800 22.4 3.79000 29.7
> tony Linux 2.4.18 0.830 1.7000 3.7500 2.7800 19.6 4.37000 29.6
> tony Linux 2.4.18 0.730 1.6700 4.0600 1.9500 22.0 3.84000 29.8
> tony Linux 2.5.40 1.090 1.9000 4.4700 2.3100 23.7 5.52000 30.6
> tony Linux 2.5.40 1.140 1.9000 4.4200 2.3100 22.3 4.01000 30.6
> tony Linux 2.5.40 1.100 1.8900 4.4700 2.1100 22.4 4.32000 30.6
> tony Linux 2.5.40 1.110 1.9300 4.4700 2.0500 23.5 3.87000 30.5
> tony Linux 2.5.40 1.130 1.9100 4.4400 2.1100 24.3 4.44000 30.6
>
> *Local* Communication latencies in microseconds - smaller is better
> -------------------------------------------------------------------
> Host OS 2p/0K Pipe AF UDP RPC/ TCP RPC/ TCP
> ctxsw UNIX UDP TCP conn
> --------- ------------- ----- ----- ---- ----- ----- ----- ----- ----
> tony Linux 2.4.18 0.850 4.991 7.30 12.8 23.1 14.4 28.0 45.2
> tony Linux 2.4.18 0.800 4.897 7.15 12.9 23.7 14.3 29.0 43.9
> tony Linux 2.4.18 0.860 4.893 7.21 12.8 23.0 14.7 28.4 599K
> tony Linux 2.4.18 0.830 4.901 7.20 12.9 23.2 14.4 28.1 44.4
> tony Linux 2.4.18 0.730 4.909 7.20 13.0 22.7 14.4 28.1 44.6
> tony Linux 2.5.40 1.090 5.235 7.92 13.7 23.6 15.2 29.3 48.3
> tony Linux 2.5.40 1.140 5.416 7.99 13.6 24.1 15.2 29.1 48.5
> tony Linux 2.5.40 1.100 5.200 7.89 13.6 23.7 15.4 29.2 49.0
> tony Linux 2.5.40 1.110 5.280 7.91 13.5 23.8 15.2 29.2 48.5
> tony Linux 2.5.40 1.130 5.462 7.89 13.6 23.7 15.3 29.0 48.3
>
> File & VM system latencies in microseconds - smaller is better
> --------------------------------------------------------------
> Host OS 0K File 10K File Mmap Prot Page
> Create Delete Create Delete Latency Fault Fault
> --------- ------------- ------ ------ ------ ------ ------- ----- -----
> tony Linux 2.4.18 29.2 5.6820 56.7 10.5 1196.0 1.324 2.00000
> tony Linux 2.4.18 29.3 5.7120 56.7 10.6 1187.0 1.318 2.00000
> tony Linux 2.4.18 29.2 5.7000 56.7 10.5 1187.0 1.352 2.00000
> tony Linux 2.4.18 29.2 5.6280 55.5 10.4 1187.0 1.331 2.00000
> tony Linux 2.4.18 29.2 5.6610 57.1 10.6 1186.0 1.309 2.00000
> tony Linux 2.5.40 32.1 6.5480 62.0 14.5 1442.0 1.338 2.00000
> tony Linux 2.5.40 32.1 6.5980 61.0 14.6 1445.0 1.341 2.00000
> tony Linux 2.5.40 32.1 6.5130 59.8 14.4 1451.0 1.343 2.00000
> tony Linux 2.5.40 32.3 6.5550 60.5 14.4 1450.0 1.307 2.00000
> tony Linux 2.5.40 32.2 6.5800 60.1 14.5 1451.0 1.411 2.00000
>
> *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
> --------- ------------- ---- ---- ---- ------ ------ ------ ------ ---- -----
> tony Linux 2.4.18 1568 2343 648. 1964.5 2007.7 840.3 907.7 2007 1078.
> tony Linux 2.4.18 1451 2326 577. 1926.7 2008.0 845.9 892.6 2004 1144.
> tony Linux 2.4.18 1575 2303 1301 1967.6 2007.8 851.6 901.4 2007 1189.
> tony Linux 2.4.18 1569 2335 1281 1966.0 2005.3 873.9 901.4 2007 1228.
> tony Linux 2.4.18 1533 2356 1118 1964.4 2007.9 887.7 913.3 2004 1272.
> tony Linux 2.5.40 1266 2120 295. 1819.4 1980.0 810.3 858.5 1975 1216.
> tony Linux 2.5.40 1366 2192 293. 1819.0 1980.8 831.4 884.1 1976 1288.
> tony Linux 2.5.40 1388 2161 278. 1815.2 1979.3 850.5 891.4 1978 1334.
> tony Linux 2.5.40 1348 2197 299. 1838.5 1979.1 842.1 904.6 1975 1360.
> tony Linux 2.5.40 1367 2192 609. 1837.7 1980.8 858.5 926.8 1975 1357.

--
bill davidsen <davidsen@tmr.com>
CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.