Re: Minutes from Feb 21 LSE Call

Cliff White
2003-02-25T17:01:40Z

> >> _If_ it harms performance on small boxes.
> >
> > You mean like the general slowdown from 2.4 - >2.5?
> >
> > It seems to me for small boxes, 2.5.x is margianlly slower at most
> > things than 2.4.x.
>
> Can you name a benchmark, or at least do something reproducible between
> versions, and produce a 2.4 vs 2.5 profile? Let's at least try to fix it ...
>
> M.

Well, here's one bit of data. Easy enough to do if you have a web browser.
LMBench 2.0 on 1-way and 2-way, kernels 2.4.18 and 2.5.60
1-way (stp1-003 stp1-002)
2.4.18 http://khack.osdl.org/stp/7443/
2.5.60 http://khack.osdl.org/stp/265622/

2-way (stp2-003 stp2-000)
2.4.18 http://khack.osdl.org/stp/3165/
2.5.60 http://khack.osdl.org/stp/265643/

Interesting items for me are the fork/exec/sh times and some of the file + VM
numbers
LMBench 2.0 Data ( items selected from total of five runs )

Processor, Processes - times in microseconds - smaller is better
----------------------------------------------------------------
Host OS Mhz null null open selct sig sig fork exec sh
call I/O stat clos TCP inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ----- ---- ---- ---- ---- ----
stp2-003. Linux 2.4.18 1000 0.39 0.67 3.89 4.99 30.4 0.93 3.06 344. 1403 4465
stp2-000. Linux 2.5.60 1000 0.41 0.77 4.34 5.57 32.6 1.15 3.59 245. 1406 5795

stp1-003. Linux 2.4.18 1000 0.32 0.46 2.60 3.21 16.6 0.79 2.52 104. 918. 4460
stp1-002. Linux 2.5.60 1000 0.33 0.47 2.83 3.47 16.0 0.94 2.70 143. 1212 5292

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
--------- ------------- ----- ------ ------ ------ ------ ------- -------
stp2-003. Linux 2.4.18 2.680 6.2100 15.8 7.9400 110.7 26.4 111.1
stp2-000. Linux 2.5.60 1.590 5.0700 17.6 7.5800 79.8 11.0 113.6

stp1-003. Linux 2.4.18 0.590 3.4700 11.1 4.8200 134.3 30.8 131.7
stp1-002. Linux 2.5.60 1.000 3.5400 11.2 4.1400 129.6 30.4 127.8

*Local* Communication latencies in microseconds - smaller is better
-------------------------------------------------------------------
Host OS 2p/0K Pipe AF UDP RPC/ TCP RPC/ TCP
ctxsw UNIX UDP TCP conn
--------- ------------- ----- ----- ---- ----- ----- ----- ----- ----
stp2-003. Linux 2.4.18 2.680 9.071 17.5 26.9 46.2 34.4 60.0 62.9
stp2-000. Linux 2.5.60 1.590 8.414 13.2 21.2 43.2 28.3 54.1 97.1

stp1-003. Linux 2.4.18 0.590 3.623 6.98 11.7 28.2 17.8 38.4 300K
stp1-002. Linux 2.5.60 1.050 4.591 8.54 14.8 31.8 20.0 41.0 67.1

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
--------- ------------- ------ ------ ------ ------ ------- ----- -----
stp2-003. Linux 2.4.18 34.6 7.2490 110.9 17.9 2642.0 0.771 3.00000
stp2-000. Linux 2.5.60 40.0 9.2780 113.3 23.3 4592.0 0.543 3.00000

stp1-003. Linux 2.4.18 28.8 4.8890 107.5 11.3 686.0 0.621 2.00000
stp1-002. Linux 2.5.60 32.4 6.4290 112.9 16.2 1455.0 0.465 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
--------- ------------- ---- ---- ---- ------ ------ ------ ------ ---- -----
stp2-003. Linux 2.4.18 563. 277. 263. 437.0 552.8 249.1 180.7 553. 215.2
stp2-000. Linux 2.5.60 603. 516. 151. 436.3 549.0 238.0 171.9 548. 233.7

stp1-003. Linux 2.4.18 1009 820. 404. 414.3 467.0 167.2 154.1 466. 236.2
stp1-002. Linux 2.5.60 806. 584. 69.1 408.0 461.7 161.1 149.1 461. 233.5

Memory latencies in nanoseconds - smaller is better
(WARNING - may not be correct, check graphs)
---------------------------------------------------
Host OS Mhz L1 $ L2 $ Main mem Guesses
--------- ------------- ---- ----- ------ -------- -------
stp2-003. Linux 2.4.18 1000 3.464 8.0820 110.9
stp2-000. Linux 2.5.60 1000 3.545 8.2790 110.6

stp1-003. Linux 2.4.18 1000 2.994 6.9850 121.4
stp1-002. Linux 2.5.60 1000 3.023 7.0530 122.5

------------------
cliffw

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