lkml.org 
[lkml]   [2002]   [Aug]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH] tsc-disable_B9
    Alan Cox writes:
    > On Thu, 2002-08-15 at 17:56, Andrea Arcangeli wrote:
    > > sorry but I don't see the point of badtsc only in kernel.
    > >
    > > If the TSC is bad that will be in particular bad from userspace where
    > > there's no hope to know what CPU you're running on.
    >
    > You can still do meaningful measurements for things like profiling
    > because the cpu hop is statistically uninteresting.

    There are kernel extensions around that handle process migration across
    CPUs while providing virtualised per-process TSC counts, and for which
    the TSCs do NOT need to be in perfect sync.

    Disabling user-space RDTSC just because the TSCs aren't in sync is stupid.

    /Mikael
    -
    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 13:28    [W:0.051 / U:0.460 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site