[lkml]   [2001]   [Oct]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: SMP processor rework help needed
    On 14 Oct 2001, Andi Kleen wrote:

    > In article <000b01c154ee$1d6a2610$6400a8c0@it0>,
    > "Tommy Faasen" <> writes:
    > > Hi,
    > > I have this unique situation where cpu 1 has less features (like fxsr) then
    > > cpu 0.
    > I used to have such an AMP machine too: a dual PII-300 with one Katmai and one
    > Deschutes. It's technically a violation of the specs; the Intel SMP spec
    > requires that the non boot cpus need to have a superset of the features
    > of the boot CPU. One CPU died, so it is symmetric now.
    > For most capabilities it should already work in 2.4 after hpa's cpu
    > set rewrite, but FXSAVE is unfortunately a bit of a special case because
    > it is used in the scheduler context switch and that is required early
    > in the initialization for SMP bootup and changing it would be very
    > intrusive.
    > In the 2.2 SuSE kernel it was fixed instead by adding a new kernel
    > command line option nofxsave that overrides the FXSAVE bit on the first
    > CPU. That is ok because such setup is very rare and is only generated by
    > people who build their own boxes; and these should also know how to pass
    > kernel command line arguments.

    This may sound like a dumb question but wouldn't simply swapping the CPUs
    have the same affect?


    Gerhard Mack

    <>< As a computer I find your faith in technology amusing.

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:18    [W:0.024 / U:1.876 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site