14 Oct
2002
14 Oct
'02
6:39 a.m.
Joern Nettingsmeier wrote:
some new interesting results with 2.5.42:
http://spunk.dnsalias.org/latencytest/2.5.42/2x256.html
overall much worse, *but* greatly reduced latency peaks (max. 6 ms) as
compared to 2.5.41:
http://spunk.dnsalias.org/latencytest/2.5.41/2x256.html
here the peaks easily reach 13 ms.
Rather depends on the filesystem. ext3 does its own write scheduling,
and does stuff inside lock_kernel(). It needs a couple of scheduling
points I guess.
I'd expect ext2 to work OK with preemption, but nobody has really
looked yet. Unless you're using ftruncate() (grr.)
i'm not really sure what to make of this....
can someone explain ?
andrew, it seems part of your mm patch was merged - is there an updated
patch around that will add the missing hunks ?
Well 2.5.41 had the big change to the truncate code, which was
a rather important part of this whole effort. I can't immediately
think of a 2.5.42 change which would do this...
But nobody has really got down and dug out the toolkit on
2.5 scheduling latency. I guess I should do that soon.