RE: increased translation cache footprint in v2.6

Al Boldi
2005-06-27T19:06:58Z

Marcelo Tosatti wrote:

> We've noticed a slowdown while moving from v2.4 to v2.6 on a small PPC
> platform (855T CPU running at 48Mhz, containing pair of separate I/D
> TLB caches with
> 32 entries each), with a relatively recent kernel (v2.6.11).
>
> Test in question is a "dd" copying 16MB from /dev/zero to RAMDISK.
>
> Which is about 16% of 48000000, the total number of cycles this CPU
performs on one second.

Testing with hdparm -tT /dev/hda shows an 18% slowdown on a PII-400Mhz using
2.4.31/2.6.11.

WHAT'S going on?