On 10/28/05, Lee Revell <rlrevell@xxxxxxxxxxx> wrote: > On Fri, 2005-10-28 at 03:31 +0100, Alistair John Strachan wrote: > > On Friday 28 October 2005 00:18, Claudio Scordino wrote: > > > Hi, > > > > > > during the last years there has been a lot of discussion about the > > > "best" value of HZ... On i386 was 100, then became 1000, and finally was > > > set to 250. I'm thinking to do an evaluation of this parameter using > > > different architectures. > > > > > > Has anybody thought to give the possibility to modify the value of HZ at > > > boot time instead of at compile time ? This would allow to easily test > > > different values on different machines and create a table containing the > > > "best" value for each architecture... At this moment, instead, we have to > > > recompile the kernel for each different value :( > > > > > > Do you think there would be much work to do that ? > > > Do you think it would be a desired feature the knowledge of the best value > > > for each architecture with more precision ? > > > > Google for "dynticks". There's obviously an overhead associated with HZ not > > being a constant (the compiler cannot optimise many expressions), but the > > feature is being worked on nonetheless. > > > > Well Linus had the best idea in that thread (as usual) which was to > implement "dynamic ticks" by leaving HZ a constant, setting it to a high > value, and skipping ticks when idle. Has there been any work in that > direction? > i did a bit of work in that area, but the stuff I came up with never seemed to work right, so I dropped it. -- Jesper Juhl <jesper.juhl@xxxxxxxxx> Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html Plain text mails only, please http://www.expita.com/nomime.html -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
