30 Mar, 2010

1 commit

  • …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

25 Jul, 2008

1 commit

  • On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit
    boundary. For example:

    u64 val = PAGE_ALIGN(size);

    always returns a value < 4GB even if size is greater than 4GB.

    The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for
    example):

    #define PAGE_SHIFT 12
    #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
    #define PAGE_MASK (~(PAGE_SIZE-1))
    ...
    #define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK)

    The "~" is performed on a 32-bit value, so everything in "and" with
    PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary.
    Using the ALIGN() macro seems to be the right way, because it uses
    typeof(addr) for the mask.

    Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in
    include/linux/mm.h.

    See also lkml discussion: http://lkml.org/lkml/2008/6/11/237

    [akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c]
    [akpm@linux-foundation.org: fix v850]
    [akpm@linux-foundation.org: fix powerpc]
    [akpm@linux-foundation.org: fix arm]
    [akpm@linux-foundation.org: fix mips]
    [akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c]
    [akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c]
    [akpm@linux-foundation.org: fix powerpc]
    Signed-off-by: Andrea Righi
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrea Righi
     

26 Oct, 2006

1 commit


01 Oct, 2006

1 commit


26 Sep, 2006

1 commit

  • This adds support for the Atmel AVR32 architecture as well as the AT32AP7000
    CPU and the AT32STK1000 development board.

    AVR32 is a new high-performance 32-bit RISC microprocessor core, designed for
    cost-sensitive embedded applications, with particular emphasis on low power
    consumption and high code density. The AVR32 architecture is not binary
    compatible with earlier 8-bit AVR architectures.

    The AVR32 architecture, including the instruction set, is described by the
    AVR32 Architecture Manual, available from

    http://www.atmel.com/dyn/resources/prod_documents/doc32000.pdf

    The Atmel AT32AP7000 is the first CPU implementing the AVR32 architecture. It
    features a 7-stage pipeline, 16KB instruction and data caches and a full
    Memory Management Unit. It also comes with a large set of integrated
    peripherals, many of which are shared with the AT91 ARM-based controllers from
    Atmel.

    Full data sheet is available from

    http://www.atmel.com/dyn/resources/prod_documents/doc32003.pdf

    while the CPU core implementation including caches and MMU is documented by
    the AVR32 AP Technical Reference, available from

    http://www.atmel.com/dyn/resources/prod_documents/doc32001.pdf

    Information about the AT32STK1000 development board can be found at

    http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3918

    including a BSP CD image with an earlier version of this patch, development
    tools (binaries and source/patches) and a root filesystem image suitable for
    booting from SD card.

    Alternatively, there's a preliminary "getting started" guide available at
    http://avr32linux.org/twiki/bin/view/Main/GettingStarted which provides links
    to the sources and patches you will need in order to set up a cross-compiling
    environment for avr32-linux.

    This patch, as well as the other patches included with the BSP and the
    toolchain patches, is actively supported by Atmel Corporation.

    [dmccr@us.ibm.com: Fix more pxx_page macro locations]
    [bunk@stusta.de: fix `make defconfig']
    Signed-off-by: Haavard Skinnemoen
    Signed-off-by: Adrian Bunk
    Signed-off-by: Dave McCracken
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Haavard Skinnemoen