softupdates performance...

Rahul Siddharthan rsidd at online.fr
Thu May 27 11:14:23 PDT 2004


I was interested to read this posting from Bruce Evans on freebsd-current:

http://docs.FreeBSD.org/cgi/mid.cgi?20040527120819.B8434
   soft
   updates uses extra CPU cycles to try to speed up i/o to real drives (and
   lately it doesn't seem to be very successful in doing the latter -- here
   it is now about the same speed as normal mounts for copying /usr/src but
   was 1.5 times faster a few years ago; async mounts are still 2.5 times
   faster).

I haven't tested softupdates vs non-softupdates on my DFly slice, but
my subjective impression is that it is indeed much slower than it used
to be: any disk IO takes ages, and slows down everything else too.
It certainly "seems" like it was much faster on FreeBSD 4.x a year ago
on my old (and much slower) laptop.  Linux ext3 seems much faster too.

Any ideas?

Rahul





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