Re: [9fans] Support for Mac OS X Leopard - Plan9

This is a discussion on Re: [9fans] Support for Mac OS X Leopard - Plan9 ; > if you don't mind your parallels p9 to run with the wrong time you can > simply stop timesync and you'll have no issues with suspend/restart. > the problem is that when timesync puts the new time in after ...

+ Reply to Thread
Results 1 to 3 of 3

Thread: Re: [9fans] Support for Mac OS X Leopard

  1. Re: [9fans] Support for Mac OS X Leopard

    > if you don't mind your parallels p9 to run with the wrong time you can
    > simply stop timesync and you'll have no issues with suspend/restart.
    > the problem is that when timesync puts the new time in after a suspend
    > the system recalculated the cpu clock rate and forces it down the
    > cpu's throat, which causes time to run much faster than usual.


    to be fair, timesync is in a bit of a hard situation.
    it just found out that an hour (say) of real time
    went by in the last (say) million cycles.

    the right thing to do is to fix timesync to notice
    such jumps and write them off as suspend/resume
    instead of assuming that the cpu has gotten *very* slow.

    russ


  2. Re: [9fans] Support for Mac OS X Leopard

    > the right thing to do is to fix timesync to notice
    > such jumps and write them off as suspend/resume
    > instead of assuming that the cpu has gotten *very* slow.


    timesync still needs to set the correct time (a system which was
    suspended for, say, 10 hours will live 10 hours in the past). perhaps
    devcons.c:^writebintime should be the one to skip updating the clock
    frequency?

  3. Re: [9fans] Support for Mac OS X Leopard

    >> the right thing to do is to fix timesync to notice
    >> such jumps and write them off as suspend/resume
    >> instead of assuming that the cpu has gotten *very* slow.

    >
    > timesync still needs to set the correct time (a system which was
    > suspended for, say, 10 hours will live 10 hours in the past). perhaps
    > devcons.c:^writebintime should be the one to skip updating the clock
    > frequency?


    timesync is in charge of figuring out the
    correspondence between cpu frequency
    and real time. the kernel does what timesync
    says. instead of the kernel second-guessing
    timesync, timesync should just be fixed.

    sometimes clock speed *does* vary w.r.t. real time.
    if i switch from ac to battery on a laptop,
    then timesync helps navigate the change
    in cpu frequency.

    russ


+ Reply to Thread