2.4.18-pre3-ac2 performance regression(?) vs. 2.4.17

2.4.18-pre3-ac2 performance regression(?) vs. 2.4.17

[Florin Iucha]

[-- Attachment #1: Type: text/plain, Size: 1398 bytes --]

Rik, Alan,

I have downloaded 2.4.18-pre3-ac2 out of curiosity for the VM and IDE
performance.

As a "benchmark" I ran hdparm -Tt /dev/hda. The results were surprising:

2.4.17

/dev/hda:
 Timing buffer-cache reads:   128 MB in  0.86 seconds =148.84 MB/sec
 Timing buffered disk reads:  64 MB in  3.95 seconds = 16.20 MB/sec

 Timing buffer-cache reads:   128 MB in  0.90 seconds =142.22 MB/sec
 Timing buffered disk reads:  64 MB in  4.05 seconds = 15.80 MB/sec

 Timing buffer-cache reads:   128 MB in  0.88 seconds =145.45 MB/sec
 Timing buffered disk reads:  64 MB in  4.00 seconds = 16.00 MB/sec

2.4.18-pre3-ac2

/dev/hda:
 Timing buffer-cache reads:   128 MB in  0.99 seconds =129.29 MB/sec
 Timing buffered disk reads:  64 MB in  3.90 seconds = 16.41 MB/sec

 Timing buffer-cache reads:   128 MB in  0.93 seconds =137.63 MB/sec
 Timing buffered disk reads:  64 MB in  4.03 seconds = 15.88 MB/sec

 Timing buffer-cache reads:   128 MB in  0.92 seconds =139.13 MB/sec
 Timing buffered disk reads:  64 MB in  3.90 seconds = 16.41 MB/sec

So while I see a slight (un)expected improvement in IDE performance, I
also see a degradation in memory? performance.

The box is a PIII/700MHz laptop with 256 Mb RAM. hdparm is version 4.5

Cheers,
florin

-- 

"If it's not broken, let's fix it till it is."

41A9 2BDE 8E11 F1C5 87A6  03EE 34B3 E075 3B90 DFE4

[-- Attachment #2: Type: application/pgp-signature, Size: 232 bytes --]