13 Jul, 2020

1 commit


10 Jun, 2020

1 commit

  • Patch series "mm: consolidate definitions of page table accessors", v2.

    The low level page table accessors (pXY_index(), pXY_offset()) are
    duplicated across all architectures and sometimes more than once. For
    instance, we have 31 definition of pgd_offset() for 25 supported
    architectures.

    Most of these definitions are actually identical and typically it boils
    down to, e.g.

    static inline unsigned long pmd_index(unsigned long address)
    {
    return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
    }

    static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
    {
    return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
    }

    These definitions can be shared among 90% of the arches provided
    XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

    For architectures that really need a custom version there is always
    possibility to override the generic version with the usual ifdefs magic.

    These patches introduce include/linux/pgtable.h that replaces
    include/asm-generic/pgtable.h and add the definitions of the page table
    accessors to the new header.

    This patch (of 12):

    The linux/mm.h header includes to allow inlining of the
    functions involving page table manipulations, e.g. pte_alloc() and
    pmd_alloc(). So, there is no point to explicitly include
    in the files that include .

    The include statements in such cases are remove with a simple loop:

    for f in $(git grep -l "include ") ; do
    sed -i -e '/include / d' $f
    done

    Signed-off-by: Mike Rapoport
    Signed-off-by: Andrew Morton
    Cc: Arnd Bergmann
    Cc: Borislav Petkov
    Cc: Brian Cain
    Cc: Catalin Marinas
    Cc: Chris Zankel
    Cc: "David S. Miller"
    Cc: Geert Uytterhoeven
    Cc: Greentime Hu
    Cc: Greg Ungerer
    Cc: Guan Xuetao
    Cc: Guo Ren
    Cc: Heiko Carstens
    Cc: Helge Deller
    Cc: Ingo Molnar
    Cc: Ley Foon Tan
    Cc: Mark Salter
    Cc: Matthew Wilcox
    Cc: Matt Turner
    Cc: Max Filippov
    Cc: Michael Ellerman
    Cc: Michal Simek
    Cc: Mike Rapoport
    Cc: Nick Hu
    Cc: Paul Walmsley
    Cc: Richard Weinberger
    Cc: Rich Felker
    Cc: Russell King
    Cc: Stafford Horne
    Cc: Thomas Bogendoerfer
    Cc: Thomas Gleixner
    Cc: Tony Luck
    Cc: Vincent Chen
    Cc: Vineet Gupta
    Cc: Will Deacon
    Cc: Yoshinori Sato
    Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
    Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
    Signed-off-by: Linus Torvalds

    Mike Rapoport
     

21 May, 2019

1 commit


25 Mar, 2019

2 commits

  • These dummy implementations are no better than
    default_arch_gettimeoffset() so remove them.

    Signed-off-by: Finn Thain
    Signed-off-by: Geert Uytterhoeven

    Finn Thain
     
  • Some platforms execute their timer handler with the interrupt priority
    level set below 6. That means the handler could be interrupted by another
    driver and this could lead to re-entry of the timer core.

    Avoid this by use of local_irq_save/restore for timer interrupt dispatch.
    This provides mutual exclusion around the timer interrupt flag access
    which is needed later in this series for the clocksource conversion.

    Reported-by: Thomas Gleixner
    Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1811131407120.2697@nanos.tec.linutronix.de
    Signed-off-by: Finn Thain
    Signed-off-by: Geert Uytterhoeven

    Finn Thain
     

13 Mar, 2019

1 commit

  • Add check for the return value of memblock_alloc*() functions and call
    panic() in case of error. The panic message repeats the one used by
    panicing memblock allocators with adjustment of parameters to include
    only relevant ones.

    The replacement was mostly automated with semantic patches like the one
    below with manual massaging of format strings.

    @@
    expression ptr, size, align;
    @@
    ptr = memblock_alloc(size, align);
    + if (!ptr)
    + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__, size, align);

    [anders.roxell@linaro.org: use '%pa' with 'phys_addr_t' type]
    Link: http://lkml.kernel.org/r/20190131161046.21886-1-anders.roxell@linaro.org
    [rppt@linux.ibm.com: fix format strings for panics after memblock_alloc]
    Link: http://lkml.kernel.org/r/1548950940-15145-1-git-send-email-rppt@linux.ibm.com
    [rppt@linux.ibm.com: don't panic if the allocation in sparse_buffer_init fails]
    Link: http://lkml.kernel.org/r/20190131074018.GD28876@rapoport-lnx
    [akpm@linux-foundation.org: fix xtensa printk warning]
    Link: http://lkml.kernel.org/r/1548057848-15136-20-git-send-email-rppt@linux.ibm.com
    Signed-off-by: Mike Rapoport
    Signed-off-by: Anders Roxell
    Reviewed-by: Guo Ren [c-sky]
    Acked-by: Paul Burton [MIPS]
    Acked-by: Heiko Carstens [s390]
    Reviewed-by: Juergen Gross [Xen]
    Reviewed-by: Geert Uytterhoeven [m68k]
    Acked-by: Max Filippov [xtensa]
    Cc: Catalin Marinas
    Cc: Christophe Leroy
    Cc: Christoph Hellwig
    Cc: "David S. Miller"
    Cc: Dennis Zhou
    Cc: Greentime Hu
    Cc: Greg Kroah-Hartman
    Cc: Guan Xuetao
    Cc: Guo Ren
    Cc: Mark Salter
    Cc: Matt Turner
    Cc: Michael Ellerman
    Cc: Michal Simek
    Cc: Petr Mladek
    Cc: Richard Weinberger
    Cc: Rich Felker
    Cc: Rob Herring
    Cc: Rob Herring
    Cc: Russell King
    Cc: Stafford Horne
    Cc: Tony Luck
    Cc: Vineet Gupta
    Cc: Yoshinori Sato
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mike Rapoport
     

31 Oct, 2018

3 commits

  • When a memblock allocation APIs are called with align = 0, the alignment
    is implicitly set to SMP_CACHE_BYTES.

    Implicit alignment is done deep in the memblock allocator and it can
    come as a surprise. Not that such an alignment would be wrong even
    when used incorrectly but it is better to be explicit for the sake of
    clarity and the prinicple of the least surprise.

    Replace all such uses of memblock APIs with the 'align' parameter
    explicitly set to SMP_CACHE_BYTES and stop implicit alignment assignment
    in the memblock internal allocation functions.

    For the case when memblock APIs are used via helper functions, e.g. like
    iommu_arena_new_node() in Alpha, the helper functions were detected with
    Coccinelle's help and then manually examined and updated where
    appropriate.

    The direct memblock APIs users were updated using the semantic patch below:

    @@
    expression size, min_addr, max_addr, nid;
    @@
    (
    |
    - memblock_alloc_try_nid_raw(size, 0, min_addr, max_addr, nid)
    + memblock_alloc_try_nid_raw(size, SMP_CACHE_BYTES, min_addr, max_addr,
    nid)
    |
    - memblock_alloc_try_nid_nopanic(size, 0, min_addr, max_addr, nid)
    + memblock_alloc_try_nid_nopanic(size, SMP_CACHE_BYTES, min_addr, max_addr,
    nid)
    |
    - memblock_alloc_try_nid(size, 0, min_addr, max_addr, nid)
    + memblock_alloc_try_nid(size, SMP_CACHE_BYTES, min_addr, max_addr, nid)
    |
    - memblock_alloc(size, 0)
    + memblock_alloc(size, SMP_CACHE_BYTES)
    |
    - memblock_alloc_raw(size, 0)
    + memblock_alloc_raw(size, SMP_CACHE_BYTES)
    |
    - memblock_alloc_from(size, 0, min_addr)
    + memblock_alloc_from(size, SMP_CACHE_BYTES, min_addr)
    |
    - memblock_alloc_nopanic(size, 0)
    + memblock_alloc_nopanic(size, SMP_CACHE_BYTES)
    |
    - memblock_alloc_low(size, 0)
    + memblock_alloc_low(size, SMP_CACHE_BYTES)
    |
    - memblock_alloc_low_nopanic(size, 0)
    + memblock_alloc_low_nopanic(size, SMP_CACHE_BYTES)
    |
    - memblock_alloc_from_nopanic(size, 0, min_addr)
    + memblock_alloc_from_nopanic(size, SMP_CACHE_BYTES, min_addr)
    |
    - memblock_alloc_node(size, 0, nid)
    + memblock_alloc_node(size, SMP_CACHE_BYTES, nid)
    )

    [mhocko@suse.com: changelog update]
    [akpm@linux-foundation.org: coding-style fixes]
    [rppt@linux.ibm.com: fix missed uses of implicit alignment]
    Link: http://lkml.kernel.org/r/20181016133656.GA10925@rapoport-lnx
    Link: http://lkml.kernel.org/r/1538687224-17535-1-git-send-email-rppt@linux.vnet.ibm.com
    Signed-off-by: Mike Rapoport
    Suggested-by: Michal Hocko
    Acked-by: Paul Burton [MIPS]
    Acked-by: Michael Ellerman [powerpc]
    Acked-by: Michal Hocko
    Cc: Catalin Marinas
    Cc: Chris Zankel
    Cc: Geert Uytterhoeven
    Cc: Guan Xuetao
    Cc: Ingo Molnar
    Cc: Matt Turner
    Cc: Michal Simek
    Cc: Richard Weinberger
    Cc: Russell King
    Cc: Thomas Gleixner
    Cc: Tony Luck
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mike Rapoport
     
  • Move remaining definitions and declarations from include/linux/bootmem.h
    into include/linux/memblock.h and remove the redundant header.

    The includes were replaced with the semantic patch below and then
    semi-automated removal of duplicated '#include

    @@
    @@
    - #include
    + #include

    [sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h]
    Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au
    [sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h]
    Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au
    [sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal]
    Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au
    Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com
    Signed-off-by: Mike Rapoport
    Signed-off-by: Stephen Rothwell
    Acked-by: Michal Hocko
    Cc: Catalin Marinas
    Cc: Chris Zankel
    Cc: "David S. Miller"
    Cc: Geert Uytterhoeven
    Cc: Greentime Hu
    Cc: Greg Kroah-Hartman
    Cc: Guan Xuetao
    Cc: Ingo Molnar
    Cc: "James E.J. Bottomley"
    Cc: Jonas Bonn
    Cc: Jonathan Corbet
    Cc: Ley Foon Tan
    Cc: Mark Salter
    Cc: Martin Schwidefsky
    Cc: Matt Turner
    Cc: Michael Ellerman
    Cc: Michal Simek
    Cc: Palmer Dabbelt
    Cc: Paul Burton
    Cc: Richard Kuo
    Cc: Richard Weinberger
    Cc: Rich Felker
    Cc: Russell King
    Cc: Serge Semin
    Cc: Thomas Gleixner
    Cc: Tony Luck
    Cc: Vineet Gupta
    Cc: Yoshinori Sato
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mike Rapoport
     
  • The alloc_bootmem(size) is a shortcut for allocation of SMP_CACHE_BYTES
    aligned memory. When the align parameter of memblock_alloc() is 0, the
    alignment is implicitly set to SMP_CACHE_BYTES and thus alloc_bootmem(size)
    and memblock_alloc(size, 0) are equivalent.

    The conversion is done using the following semantic patch:

    @@
    expression size;
    @@
    - alloc_bootmem(size)
    + memblock_alloc(size, 0)

    Link: http://lkml.kernel.org/r/1536927045-23536-22-git-send-email-rppt@linux.vnet.ibm.com
    Signed-off-by: Mike Rapoport
    Cc: Catalin Marinas
    Cc: Chris Zankel
    Cc: "David S. Miller"
    Cc: Geert Uytterhoeven
    Cc: Greentime Hu
    Cc: Greg Kroah-Hartman
    Cc: Guan Xuetao
    Cc: Ingo Molnar
    Cc: "James E.J. Bottomley"
    Cc: Jonas Bonn
    Cc: Jonathan Corbet
    Cc: Ley Foon Tan
    Cc: Mark Salter
    Cc: Martin Schwidefsky
    Cc: Matt Turner
    Cc: Michael Ellerman
    Cc: Michal Hocko
    Cc: Michal Simek
    Cc: Palmer Dabbelt
    Cc: Paul Burton
    Cc: Richard Kuo
    Cc: Richard Weinberger
    Cc: Rich Felker
    Cc: Russell King
    Cc: Serge Semin
    Cc: Thomas Gleixner
    Cc: Tony Luck
    Cc: Vineet Gupta
    Cc: Yoshinori Sato
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mike Rapoport
     

29 Jul, 2018

1 commit

  • In m68k the physical memory is described by [memory_start, memory_end] for
    !MMU variant and by m68k_memory array of memory ranges for the MMU version.
    This information is directly use to register the physical memory with
    memblock.

    The reserve_bootmem() calls are replaced with memblock_reserve() and the
    bootmap bitmap allocation is simply dropped.

    Since the MMU variant creates early mappings only for the small part of the
    memory we force bottom-up allocations in memblock.

    Signed-off-by: Mike Rapoport
    Acked-by: Greg Ungerer
    Signed-off-by: Geert Uytterhoeven

    Mike Rapoport
     

22 May, 2018

1 commit

  • This fixes a bug in read_persistent_clock() which causes the system
    clock to lag the Real Time Clock by one month. The problem was noticed
    on a Mac, but theoretically it must also affect Atari, BVME6000 and Q40.

    The tm_mon value in the struct rtc_time passed to mach_hwclk() is
    zero-based, and atari_mste_hwclk(), atari_tt_hwclk(), bvme6000_hwclk(),
    mac_hwclk() and q40_hwclk() all make this adjustment. Unfortunately,
    dn_dummy_hwclk(), mvme147_hwclk(), mvme16x_hwclk(), sun3_hwclk() and
    sun3x_hwclk() fail to decrement tm_mon. Also m68328_hwclk() assumes
    a one-based tm_mon.

    Bring these platforms into line and fix read_persistent_clock() so it
    works correctly on all m68k platforms.

    The datasheets for the RTC devices found on the affected platforms
    all confirm that the year is stored as a value in the range 0-99 and
    the month is stored as a value in the range 1-12. Please refer to the
    datasheets for MC146818 (Apollo), DS1643 (MVME), ICM7170 (Sun 3)
    and M48T02 (Sun 3x).

    Reported-by: Stan Johnson
    Signed-off-by: Finn Thain
    Reviewed-by: Arnd Bergmann
    Signed-off-by: Geert Uytterhoeven

    Finn Thain
     

02 Nov, 2017

1 commit

  • Many source files in the tree are missing licensing information, which
    makes it harder for compliance tools to determine the correct license.

    By default all files without license information are under the default
    license of the kernel, which is GPL version 2.

    Update the files which contain no license information with the 'GPL-2.0'
    SPDX license identifier. The SPDX identifier is a legally binding
    shorthand, which can be used instead of the full boiler plate text.

    This patch is based on work done by Thomas Gleixner and Kate Stewart and
    Philippe Ombredanne.

    How this work was done:

    Patches were generated and checked against linux-4.14-rc6 for a subset of
    the use cases:
    - file had no licensing information it it.
    - file was a */uapi/* one with no licensing information in it,
    - file was a */uapi/* one with existing licensing information,

    Further patches will be generated in subsequent months to fix up cases
    where non-standard license headers were used, and references to license
    had to be inferred by heuristics based on keywords.

    The analysis to determine which SPDX License Identifier to be applied to
    a file was done in a spreadsheet of side by side results from of the
    output of two independent scanners (ScanCode & Windriver) producing SPDX
    tag:value files created by Philippe Ombredanne. Philippe prepared the
    base worksheet, and did an initial spot review of a few 1000 files.

    The 4.13 kernel was the starting point of the analysis with 60,537 files
    assessed. Kate Stewart did a file by file comparison of the scanner
    results in the spreadsheet to determine which SPDX license identifier(s)
    to be applied to the file. She confirmed any determination that was not
    immediately clear with lawyers working with the Linux Foundation.

    Criteria used to select files for SPDX license identifier tagging was:
    - Files considered eligible had to be source code files.
    - Make and config files were included as candidates if they contained >5
    lines of source
    - File already had some variant of a license header in it (even if
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

02 Mar, 2017

1 commit

  • We are going to split out of , which
    will have to be picked up from other headers and a couple of .c files.

    Create a trivial placeholder file that just
    maps to to make this patch obviously correct and
    bisectable.

    The APIs that are going to be moved first are:

    mm_alloc()
    __mmdrop()
    mmdrop()
    mmdrop_async_fn()
    mmdrop_async()
    mmget_not_zero()
    mmput()
    mmput_async()
    get_task_mm()
    mm_access()
    mm_release()

    Include the new header in the files that are going to need it.

    Acked-by: Linus Torvalds
    Cc: Mike Galbraith
    Cc: Peter Zijlstra
    Cc: Thomas Gleixner
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: Ingo Molnar

    Ingo Molnar
     

12 Feb, 2017

1 commit


25 Dec, 2016

1 commit


04 Jun, 2016

1 commit

  • The asm/rtc.h header is only used for the old gen_rtc driver
    that has been replaced by rtc-generic. According to Geert
    Uytterhoeven, nobody has used the old driver on m68k for
    a long time, so we can now just remove the header file
    and disallow the driver in Kconfig.

    All files that used to include asm/rtc.h are now changed so
    they include the headers that were used implicitly through
    asm/rtc.h.

    Signed-off-by: Arnd Bergmann
    Acked-by: Geert Uytterhoeven
    Tested-by: Geert Uytterhoeven
    Signed-off-by: Alexandre Belloni

    Arnd Bergmann
     

13 Jan, 2016

1 commit


10 Jan, 2016

1 commit


22 Nov, 2015

1 commit

  • If max_pfn is not initialized, the various /proc/kpage* files are empty,
    and selftests/vm/mlock2-tests will fail. max_pfn is also used by the
    block layer to calculate DMA masks.

    Switch from init_bootmem_node() to init_bootmem(), as there's only one
    memory node on Sun-3. This will initialize min_low_pfn and max_low_pfn,
    which was also not done before.

    Signed-off-by: Geert Uytterhoeven
    Acked-by: Greg Ungerer

    Geert Uytterhoeven
     

13 Sep, 2015

1 commit


20 Nov, 2014

1 commit


26 Nov, 2013

2 commits


25 Jun, 2013

1 commit


25 Dec, 2012

1 commit

  • remove m68k's mach_gettimeoffset function pointer, and instead directly
    set the arch_gettimeoffset function pointer. This requires multiplying
    all function results by 1000, since the removed m68k_gettimeoffset() did
    this. Also, s/unsigned long/u32/ just to make the function prototypes
    exactly match that of arch_gettimeoffset.

    Cc: Joshua Thompson
    Cc: Sam Creasey
    Acked-by: Geert Uytterhoeven
    Acked-by: Phil Blundell
    Signed-off-by: Stephen Warren

    Stephen Warren
     

14 Nov, 2012

1 commit

  • SUN3 Intregister is not for enabling individual interrupts, but to enable
    special interrupts. So using it for interrupt enable/disable was wrong.
    The clock interrupt needs some special treatment to keep ticking.

    Signed-off-by: Thomas Bogendoerfer
    Signed-off-by: Geert Uytterhoeven

    Thomas Bogendoerfer
     

27 Jun, 2012

1 commit


29 Mar, 2012

1 commit


09 Nov, 2011

8 commits


31 Jan, 2011

1 commit

  • xtime_update() properly takes the xtime_lock

    Signed-off-by: Torben Hohn
    Cc: Sam Creasey
    Cc: Peter Zijlstra
    Cc: johnstul@us.ibm.com
    Cc: Roman Zippel
    Cc: hch@infradead.org
    Cc: yong.zhang0@gmail.com
    Cc: Geert Uytterhoeven
    Cc: Greg Ungerer
    LKML-Reference:
    Signed-off-by: Thomas Gleixner

    Torben Hohn
     

22 Oct, 2010

1 commit


10 Aug, 2010

1 commit


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