[lkml]   [2011]   [Feb]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: Performance/resume issues on Toshiba NB305
    On Fri, Feb 25, 2011 at 03:17:47PM -0500, Steven Rostedt wrote:
    > Would be helpful to Cc the people that may help you.
    > On Fri, Feb 25, 2011 at 10:42:39AM -0600, Seth Forshee wrote:
    > > I've been looking into a couple of problems with this machine that have
    > > me a bit stumped at the moment. The two problems may or may not be
    > > related, so I'm including details about both issues below. If anyone has
    > > any ideas, I'd love to hear them. Note that these are not recent
    > > regressions; they've been around since at least 2.6.32.
    > >
    > > The CPU in this machine is an Atom N450.
    > >
    > > When booted normally the performance on this machine is very poor, but
    > > when booted with any of nohz=off, nolapic, or nohpet it improves
    > > significantly. The performance also improves if I use the patch below to
    > > force the hpet to remain in periodic mode (with hpet=periodic on the
    > > command line).
    > >
    > > One other thing I noticed when I had added some logging related to hpet
    > > rearming is 3-5 second periods of no log activity occurring fairly
    > > frequently, whereas such inactive periods are infrequent when
    > > performance is good and are also infrequent on another machine with very
    > > similar hardware and no performance issues.
    > >
    > > The machine also hangs for 5 minutes during resume, unless booted with
    > > both nohz=off and highres=off, or with hpet=periodic using the patch
    > > below. I've traced this down to hanging in an SMI handler during the
    > > ACPI _WAK method execution. The 5 minutes corresponds to how long it
    > > takes for the low 32 bits of the hpet to wrap in this machine, and since
    > > the options that eliminate the hang result in the hpet being in periodic
    > > mode during _WAK method execution I suspect that the SMI handler is
    > > hanging until a timer interrupt happens.
    > >
    > > One possible explanation here is that the performance problems are also
    > > related to hangs in SMI handlers until there's a timer interrupt,
    > > although I don't know how that explains why some of the command line
    > > options eliminate the performance issues.
    > Sounds like a buggy BIOS to me. Is there upgrades available for this
    > box?

    It does sound like a buggy BIOS. I've already flashed the latest BIOS
    though, so no luck there.

     \ /
      Last update: 2011-02-25 21:29    [W:0.020 / U:16.856 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site