Eric Lee / smarc-fsl-linux-kernel

21 Jul, 2008

1 commit

05 Jul, 2008

2 commits

17 Jun, 2008

1 commit

17 May, 2008

1 commit

13 May, 2008

1 commit

11 May, 2008

1 commit

  • 8e3e076c5   BKL: revert back to the old spinlock implementation ... Browse Code »

    The generic semaphore rewrite had a huge performance regression on AIM7
    (and potentially other BKL-heavy benchmarks) because the generic
    semaphores had been rewritten to be simple to understand and fair. The
    latter, in particular, turns a semaphore-based BKL implementation into a
    mess of scheduling.

    The attempt to fix the performance regression failed miserably (see the
    previous commit 00b41ec2611dc98f87f30753ee00a53db648d662 'Revert
    "semaphore: fix"'), and so for now the simple and sane approach is to
    instead just go back to the old spinlock-based BKL implementation that
    never had any issues like this.

    This patch also has the advantage of being reported to fix the
    regression completely according to Yanmin Zhang, unlike the semaphore
    hack which still left a couple percentage point regression.

    As a spinlock, the BKL obviously has the potential to be a latency
    issue, but it's not really any different from any other spinlock in that
    respect. We do want to get rid of the BKL asap, but that has been the
    plan for several years.

    These days, the biggest users are in the tty layer (open/release in
    particular) and Alan holds out some hope:

    "tty release is probably a few months away from getting cured - I'm
    afraid it will almost certainly be the very last user of the BKL in
    tty to get fixed as it depends on everything else being sanely locked."

    so while we're not there yet, we do have a plan of action.

    Tested-by: Yanmin Zhang
    Cc: Ingo Molnar
    Cc: Andi Kleen
    Cc: Matthew Wilcox
    Cc: Alexander Viro
    Cc: Andrew Morton
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

04 May, 2008

1 commit

  • d35c7b0e5   unified (weak) sys_pipe implementation ... Browse Code »

    This replaces the duplicated arch-specific versions of "sys_pipe()" with
    one unified implementation. This removes almost 250 lines of duplicated
    code.

    It's marked __weak, so that *if* an architecture wants to override the
    default implementation it can do so by simply having its own replacement
    version, since many architectures use alternate calling conventions for
    the 'pipe()' system call for legacy reasons (ie traditional UNIX
    implementations often return the two file descriptors in registers)

    I still haven't changed the cris version even though Linus says the BKL
    isn't needed. The arch maintainer can easily do it if there are really
    no obstacles.

    Signed-off-by: Ulrich Drepper
    Signed-off-by: Linus Torvalds

    Ulrich Drepper
     

29 Apr, 2008

2 commits

21 Apr, 2008

1 commit

  • 1ba6ab11d   PCI: remove initial bios sort of PCI devices on x86 ... Browse Code »

    We currently keep 2 lists of PCI devices in the system, one in the
    driver core, and one all on its own. This second list is sorted at boot
    time, in "BIOS" order, to try to remain compatible with older kernels
    (2.2 and earlier days). There was also a "nosort" option to turn this
    sorting off, to remain compatible with even older kernel versions, but
    that just ends up being what we have been doing from 2.5 days...

    Unfortunately, the second list of devices is not really ever used to
    determine the probing order of PCI devices or drivers[1]. That is done
    using the driver core list instead. This change happened back in the
    early 2.5 days.

    Relying on BIOS ording for the binding of drivers to specific device
    names is problematic for many reasons, and userspace tools like udev
    exist to properly name devices in a persistant manner if that is needed,
    no reliance on the BIOS is needed.

    Matt Domsch and others at Dell noticed this back in 2006, and added a
    boot option to sort the PCI device lists (both of them) in a
    breadth-first manner to help remain compatible with the 2.4 order, if
    needed for any reason. This option is not going away, as some systems
    rely on them.

    This patch removes the sorting of the internal PCI device list in "BIOS"
    mode, as it's not needed at all anymore, and hasn't for many years.
    I've also removed the PCI flags for this from some other arches that for
    some reason defined them, but never used them.

    This should not change the ordering of any drivers or device probing.

    [1] The old-style pci_get_device and pci_find_device() still used this
    sorting order, but there are very few drivers that use these functions,
    as they are deprecated for use in this manner. If for some reason, a
    driver rely on the order and uses these functions, the breadth-first
    boot option will resolve any problem.

    Cc: Matt Domsch
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

17 Apr, 2008

1 commit

  • 64ac24e73   Generic semaphore implementation ... Browse Code »
    46

    Semaphores are no longer performance-critical, so a generic C
    implementation is better for maintainability, debuggability and
    extensibility. Thanks to Peter Zijlstra for fixing the lockdep
    warning. Thanks to Harvey Harrison for pointing out that the
    unlikely() was unnecessary.

    Signed-off-by: Matthew Wilcox
    Acked-by: Ingo Molnar

    Matthew Wilcox
     

24 Feb, 2008

1 commit

20 Feb, 2008

4 commits

09 Feb, 2008

2 commits

  • daeb51e62   mn10300: add platform MTD support for the ASB2303 board ... Browse Code »

    Add platform MTD support for the ASB2303 board.

    Signed-off-by: David Howells
    Acked-by: David Woodhouse
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Howells
     
  • b920de1b7   mn10300: add the MN10300/AM33 architecture to the kernel ... Browse Code »

    Add architecture support for the MN10300/AM33 CPUs produced by MEI to the
    kernel.

    This patch also adds board support for the ASB2303 with the ASB2308 daughter
    board, and the ASB2305. The only processor supported is the MN103E010, which
    is an AM33v2 core plus on-chip devices.

    [akpm@linux-foundation.org: nuke cvs control strings]
    Signed-off-by: Masakazu Urade
    Signed-off-by: Koichi Yasutake
    Signed-off-by: David Howells
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Howells