On Sat, 25 Sep 2004 11:19:26 +0800, Bao zhao <paozhaokeats@xxxxxxxxxxx> wrote: > In ULK 2ND chapter 11, > the author said > "#define DEF_COUNTER ( 10 * HZ / 100) > Since HZ (which denotes the frequency of timer interrupts) is set to 100 for > IBM compatible PCs (see > Section 6.1.3), the value of DEF_COUNTER is 10 ticks¡ªthat is, about 105 > ms." > > why does the value is 105 ms instead of 100ms ? I suppose he's referring to the fact that any timer event is going to get delt with 5ms between one timer tick and the next (you won't always hit a timer tick right on) so on a PC with a HZ value of 100 this makes some sense - it's also really iffy to assume values for HZ as this has since become somewhat more arbitrary (and on Intel it's typically 1000 now). Jon. -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
