Eric Lee / smarc-fsl-linux-kernel

07 Jan, 2006

1 commit

10 Nov, 2005

1 commit

  • e4d76e1c0   [PATCH] powerpc: sched fixups ... Browse Code »

    - Re-add a hunk lost during merge: ppc64 is missing the hunk that disables
    preempt on the secondary CPUs before they call cpu_idle().

    - ppc's cpu_idle() had the need_resched() test wrong.

    Cc: Nick Piggin
    CC: Benjamin Herrenschmidt
    Cc: Paul Mackerras
    Cc: Anton Blanchard
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrew Morton
     

09 Nov, 2005

2 commits

  • 64c7c8f88   [PATCH] sched: resched and cpu_idle rework ... Browse Code »

    Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce
    confusion, and make their semantics rigid. Improves efficiency of
    resched_task and some cpu_idle routines.

    * In resched_task:
    - TIF_NEED_RESCHED is only cleared with the task's runqueue lock held,
    and as we hold it during resched_task, then there is no need for an
    atomic test and set there. The only other time this should be set is
    when the task's quantum expires, in the timer interrupt - this is
    protected against because the rq lock is irq-safe.

    - If TIF_NEED_RESCHED is set, then we don't need to do anything. It
    won't get unset until the task get's schedule()d off.

    - If we are running on the same CPU as the task we resched, then set
    TIF_NEED_RESCHED and no further action is required.

    - If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set
    after TIF_NEED_RESCHED has been set, then we need to send an IPI.

    Using these rules, we are able to remove the test and set operation in
    resched_task, and make clear the previously vague semantics of
    POLLING_NRFLAG.

    * In idle routines:
    - Enter cpu_idle with preempt disabled. When the need_resched() condition
    becomes true, explicitly call schedule(). This makes things a bit clearer
    (IMO), but haven't updated all architectures yet.

    - Many do a test and clear of TIF_NEED_RESCHED for some reason. According
    to the resched_task rules, this isn't needed (and actually breaks the
    assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock
    held). So remove that. Generally one less locked memory op when switching
    to the idle thread.

    - Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner
    most polling idle loops. The above resched_task semantics allow it to be
    set until before the last time need_resched() is checked before going into
    a halt requiring interrupt wakeup.

    Many idle routines simply never enter such a halt, and so POLLING_NRFLAG
    can be always left set, completely eliminating resched IPIs when rescheduling
    the idle task.

    POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs.

    Signed-off-by: Nick Piggin
    Cc: Ingo Molnar
    Cc: Con Kolivas
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Nick Piggin
     
  • 5bfb5d690   [PATCH] sched: disable preempt in idle tasks ... Browse Code »

    Run idle threads with preempt disabled.

    Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
    How did it ever work before?

    Might fix the CPU hotplugging hang which Nigel Cunningham noted.

    We think the bug hits if the idle thread is preempted after checking
    need_resched() and before going to sleep, then the CPU offlined.

    After calling stop_machine_run, the CPU eventually returns from preemption and
    into the idle thread and goes to sleep. The CPU will continue executing
    previous idle and have no chance to call play_dead.

    By disabling preemption until we are ready to explicitly schedule, this bug is
    fixed and the idle threads generally become more robust.

    From: alexs

    PPC build fix

    From: Yoichi Yuasa

    MIPS build fix

    Signed-off-by: Nick Piggin
    Signed-off-by: Yoichi Yuasa
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Nick Piggin
     

20 Oct, 2005

1 commit

  • 17a6392d3   powerpc/ppc/ppc64: Various compile fixes. ... Browse Code »

    This declares powersave_nap in system.h and makes it an int everywhere,
    fixes typos for the maple platform, fixes a couple of places where
    I missed removing the last two arguments from a message_pass function,
    and makes ppc64 consistent with ppc32 in the type of the
    pci_bridge.cfg_data field.

    Signed-off-by: Paul Mackerras

    Paul Mackerras
     

06 Oct, 2005

1 commit

11 Sep, 2005

1 commit

  • 31139971b   [PATCH] ppc32: support hotplug cpu on powermacs ... Browse Code »

    This allows cpus to be off-lined on 32-bit SMP powermacs. When a cpu
    is off-lined, it is put into sleep mode with interrupts disabled. It
    can be on-lined again by asserting its soft-reset pin, which is
    connected to a GPIO pin.

    With this I can off-line the second cpu in my dual G4 powermac, which
    means that I can then suspend the machine (the suspend/resume code
    refuses to suspend if more than one cpu is online, and making it cope
    with multiple cpus is surprisingly messy).

    Signed-off-by: Paul Mackerras
    Signed-off-by: Linus Torvalds

    Paul Mackerras
     

17 Apr, 2005

1 commit

  • 1da177e4c   Linux-2.6.12-rc2 ... Browse Code »

    Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds