lkml.org 
[lkml]   [2005]   [May]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: Hyper-Threading Vulnerability
    From
    Date
    On Sat, 2005-05-14 at 15:21 -0400, Lee Revell wrote:
    > On Sat, 2005-05-14 at 20:01 +0200, Arjan van de Ven wrote:
    > > On Sat, 2005-05-14 at 13:56 -0400, Lee Revell wrote:
    > > > On Sat, 2005-05-14 at 18:44 +0200, Arjan van de Ven wrote:
    > > > > then JACK is terminally broken if it doesn't have a fallback for non-
    > > > > rdtsc cpus.
    > > >
    > > > It does have a fallback, but the selection is done at compile time. It
    > > > uses rdtsc for all x86 CPUs except pre-i586 SMP systems.
    > > >
    > > > Maybe we should check at runtime,
    > >
    > > it's probably a sign that JACK isn't used on SMP systems much, at least
    > > not on the bigger systems (like IBM's x440's) where the tsc *will*
    > > differ wildly between cpus...
    >
    > Correct. The only bug reports we have seen related to the use of the
    > TSC is due to CPU frequency scaling. The fix is to not use it - people
    > who want to use their PC as a DSP for audio probably don't want their
    > processor slowing down anyway.

    it's a matter of time (my estimate is a year or two) before processors
    get variable frequencies based on temperature targets etc...
    and then rdtsc is really useless for this kind of thing..


    -
    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: 2005-05-14 21:52    [W:0.020 / U:214.912 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site