On Wed, Jan 30, 2008 at 02:55:30PM +0200, Stefan Lambrev wrote: > Greetings, > > I want to know what is the bad effect of increasing HZ too much? > And when is too much? What problems can I expect when HZ>2000? > Can I change this value without pre-compiling the kernel?
You can change HZ by adding a line to /boot/loader.conf like this: kern.hz="100" (it works on RELENG_6 and RELENG_7 and I'm using this conservative setting on all my boxes, since I don't need faster context switching) If you set HZ too high, the kernel will spend too much overhead on unnecessary context switching, and it may even reach a point (with very high values of HZ) where interrupt service routines get interrupted way too often by clock ticks; i.e. interrupts would eventually come in faster than the kernel can service them. > Because all docs I found for HZ is in src/sys/conf/NOTES and it doesn't say > much. -cpghost. -- Cordula's Web. http://www.cordula.ws/ _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
