lkml.org 
[lkml]   [2002]   [Aug]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH] tsc-disable_B9
    From
    Date
    On Fri, 2002-08-09 at 02:17, Alan Cox wrote:
    > On Fri, 2002-08-09 at 03:30, john stultz wrote:
    > > Not sure I followed that, do you mean per-cpu TSC management for
    > > gettimeofday?
    >
    > We have some x86 setups where people plug say a 300MHhz and a 450MHz
    > celeron into the same board. This works because they are same FSB,
    > different multiplier (works and intel certify being two different
    > things)

    Oh yes, with the old NUMAQ hardware here, one can mix nodes of different
    speed cpus. Once I get a chance, I'm going to begin working on this
    issue for 2.5. My plan right now is to keep per-cpu last_tsc_low and
    fast_gettimeoffset_quotient values, then round robin the timer
    interrupt.


    > Needless to say tsc does not work well on such boxes. Thats why I don't
    > trust the tsc at all in such cases. Since you'll have the nice cyclone
    > timer for the Summit it seems best not to trust it, and on the summit to
    > use the cyclone for udelay as well ?
    >
    > I agree dodgy_tsc needs to change name. Perhaps we actually want
    >
    > int tsc = select_tsc();
    >
    > switch(tsc)
    > {
    > case TSC_CYCLONE:
    > case TSC_PROCESSOR:
    > case TSC_NONE:
    > ..
    > }

    Sounds good. I'll re-work my patch and resubmit.

    thanks!
    -john

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:27    [W:0.054 / U:30.004 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site