>Historically interrupts from the 32kHz clock have not been used, except, >possibly, in powered down states to initiate a restart from suspend or >hibernate. It is possible that has changed very recently, but they >certainly weren't used historically.
Well, at least one of us is confused. Or maybe my history starts long before yours. I'm pretty sure that some of the systems I've worked on used the interrupt from the 32 KHz clock chip to drive the scheduler. Some/many systems have long had troubles keeping time if interrups get lost. That wouldn't make sense if something like the TSC was used for timekeeping. Here is the message from Dave Mills that got me thinking in the right direction: Message-ID: <[EMAIL PROTECTED]> http://groups.google.com/group/comp.protocols.time.ntp/msg/59d26948e56531d4 After that, I moved the temperature probe over to the 32 KHz crystal and my temperature data looked much cleaner. The 32 KHz crystal is off in a corner of the board. THe main CPU crystal is reasonably close to the center of the board where all the heat is generated. In the last year or two, the Linux timekeeping stuff has changed a lot, partly in order to support laptops and such that go into serious power down mode and don't want to waste a lot of battery on each tick when there is nothing to do. -- These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
