05 May, 2010

1 commit

  • Fix function prototype visibility issues when compiling for non-x86
    architectures. Tested with crosstool
    (ftp://ftp.kernel.org/pub/tools/crosstool/) with alpha, ia64 and sparc
    targets.

    Signed-off-by: Borislav Petkov
    LKML-Reference:
    Signed-off-by: H. Peter Anvin

    Borislav Petkov
     

07 Apr, 2010

2 commits

  • Add support for the hardware version of the Hamming weight function,
    popcnt, present in CPUs which advertize it under CPUID, Function
    0x0000_0001_ECX[23]. On CPUs which don't support it, we fallback to the
    default lib/hweight.c sw versions.

    A synthetic benchmark comparing popcnt with __sw_hweight64 showed almost
    a 3x speedup on a F10h machine.

    Signed-off-by: Borislav Petkov
    LKML-Reference:
    Signed-off-by: H. Peter Anvin

    Borislav Petkov
     
  • Rename the extisting runtime hweight() implementations to
    __arch_hweight(), rename the compile-time versions to __const_hweight()
    and then have hweight() pick between them.

    Suggested-by: H. Peter Anvin
    Signed-off-by: Peter Zijlstra
    LKML-Reference:
    Acked-by: H. Peter Anvin
    LKML-Reference:
    Signed-off-by: H. Peter Anvin

    Peter Zijlstra
     

15 Dec, 2009

2 commits

  • Name space cleanup. No functional change.

    Signed-off-by: Thomas Gleixner
    Acked-by: Peter Zijlstra
    Acked-by: David S. Miller
    Acked-by: Ingo Molnar
    Cc: linux-arch@vger.kernel.org

    Thomas Gleixner
     
  • The raw_spin* namespace was taken by lockdep for the architecture
    specific implementations. raw_spin_* would be the ideal name space for
    the spinlocks which are not converted to sleeping locks in preempt-rt.

    Linus suggested to convert the raw_ to arch_ locks and cleanup the
    name space instead of using an artifical name like core_spin,
    atomic_spin or whatever

    No functional change.

    Signed-off-by: Thomas Gleixner
    Acked-by: Peter Zijlstra
    Acked-by: David S. Miller
    Acked-by: Ingo Molnar
    Cc: linux-arch@vger.kernel.org

    Thomas Gleixner
     

12 Jun, 2009

1 commit

  • The existing asm-generic/atomic.h only defines the
    atomic_long type. This renames it to atomic-long.h
    so we have a place to add a truly generic atomic.h
    that can be used on all non-SMP systems.

    Signed-off-by: Remis Lima Baima
    Signed-off-by: Arnd Bergmann
    Acked-by: Ingo Molnar

    Arnd Bergmann
     

14 Jan, 2009

1 commit

  • Impact: reduce kernel image size

    Hugh Dickins noticed that older gcc versions when the kernel
    is built for code size didn't inline some of the bitops.

    Mark all complex x86 bitops that have more than a single
    asm statement or two as always inline to avoid this problem.

    Probably should be done for other architectures too.

    Ingo then found a better fix that only requires
    a single line change, but it unfortunately only
    works on gcc 4.3.

    On older gccs the original patch still makes a ~0.3% defconfig
    difference with CONFIG_OPTIMIZE_INLINING=y.

    With gcc 4.1 and a defconfig like build:

    6116998 1138540 883788 8139326 7c323e vmlinux-oi-with-patch
    6137043 1138540 883788 8159371 7c808b vmlinux-optimize-inlining

    ~20k / 0.3% difference.

    Signed-off-by: Andi Kleen
    Signed-off-by: Andrew Morton
    Signed-off-by: Ingo Molnar

    Andi Kleen
     

27 Apr, 2008

3 commits

  • Use __fls for fls64 on 64-bit archs. The implementation for
    64-bit archs is moved from x86_64 to asm-generic.

    Signed-off-by: Alexander van Heukelum
    Signed-off-by: Ingo Molnar

    Alexander van Heukelum
     
  • Add a generic __fls implementation in the same spirit as
    the generic __ffs one. It finds the last (most significant)
    set bit in the given long value.

    Signed-off-by: Alexander van Heukelum
    Signed-off-by: Ingo Molnar

    Alexander van Heukelum
     
  • This moves an optimization for searching constant-sized small
    bitmaps form x86_64-specific to generic code.

    On an i386 defconfig (the x86#testing one), the size of vmlinux hardly
    changes with this applied. I have observed only four places where this
    optimization avoids a call into find_next_bit:

    In the functions return_unused_surplus_pages, alloc_fresh_huge_page,
    and adjust_pool_surplus, this patch avoids a call for a 1-bit bitmap.
    In __next_cpu a call is avoided for a 32-bit bitmap. That's it.

    On x86_64, 52 locations are optimized with a minimal increase in
    code size:

    Current #testing defconfig:
    146 x bsf, 27 x find_next_*bit
    text data bss dec hex filename
    5392637 846592 724424 6963653 6a41c5 vmlinux

    After removing the x86_64 specific optimization for find_next_*bit:
    94 x bsf, 79 x find_next_*bit
    text data bss dec hex filename
    5392358 846592 724424 6963374 6a40ae vmlinux

    After this patch (making the optimization generic):
    146 x bsf, 27 x find_next_*bit
    text data bss dec hex filename
    5392396 846592 724424 6963412 6a40d4 vmlinux

    [ tglx@linutronix.de: build fixes ]

    Signed-off-by: Ingo Molnar

    Alexander van Heukelum
     

29 Jan, 2008

1 commit


20 Oct, 2007

1 commit

  • define first set of BIT* macros

    - move BITOP_MASK and BITOP_WORD from asm-generic/bitops/atomic.h to
    include/linux/bitops.h and rename it to BIT_MASK and BIT_WORD
    - move BITS_TO_LONGS and BITS_PER_BYTE to bitops.h too and allow easily
    define another BITS_TO_something (e.g. in event.c) by BITS_TO_TYPE macro
    Remaining (and common) BIT macro will be defined after all occurences and
    conflicts will be sorted out in the patches.

    Signed-off-by: Jiri Slaby
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jiri Slaby
     

19 Oct, 2007

1 commit

  • Introduce test_and_set_bit_lock / clear_bit_unlock bitops with lock semantics.
    Convert all architectures to use the generic implementation.

    Signed-off-by: Nick Piggin
    Acked-By: David Howells
    Cc: Richard Henderson
    Cc: Ivan Kokshaysky
    Cc: Russell King
    Cc: Haavard Skinnemoen
    Cc: Bryan Wu
    Cc: Mikael Starvik
    Cc: David Howells
    Cc: Yoshinori Sato
    Cc: "Luck, Tony"
    Cc: Hirokazu Takata
    Cc: Geert Uytterhoeven
    Cc: Roman Zippel
    Cc: Greg Ungerer
    Cc: Ralf Baechle
    Cc: Kyle McMartin
    Cc: Matthew Wilcox
    Cc: Paul Mackerras
    Cc: Benjamin Herrenschmidt
    Cc: Heiko Carstens
    Cc: Martin Schwidefsky
    Cc: Paul Mundt
    Cc: Kazumoto Kojima
    Cc: Richard Curnow
    Cc: William Lee Irwin III
    Cc: "David S. Miller"
    Cc: Jeff Dike
    Cc: Paolo 'Blaisorblade' Giarrusso
    Cc: Miles Bader
    Cc: Andi Kleen
    Cc: Chris Zankel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Nick Piggin
     

10 Jul, 2007

1 commit


09 May, 2007

1 commit


12 Oct, 2006

1 commit

  • This likely profiling is pretty fun. I found a few possible problems
    in sched.c.

    This patch may be not measurable, but when I did measure long ago,
    nooping (un)likely cost a couple of % on scheduler heavy benchmarks, so
    it all adds up.

    Tweak some branch hints:

    - the 2nd 64 bits in the bitmask is likely to be populated, because it
    contains the first 28 bits (nearly 3/4) of the normal priorities.
    (ratio of 669669:691 ~= 1000:1).

    - it isn't unlikely that context switching switches to another process. it
    might be very rapidly switching to and from the idle process (ratio of
    475815:419004 and 471330:423544). Let the branch predictor decide.

    - preempt_enable seems to be very often called in a nested preempt_disable
    or with interrupts disabled (ratio of 3567760:87965 ~= 40:1)

    Signed-off-by: Nick Piggin
    Acked-by: Ingo Molnar
    Cc: Daniel Walker
    Cc: Hua Zhong
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Nick Piggin
     

27 Mar, 2006

14 commits

  • This patch introduces the C-language equivalents of the functions below:

    int minix_test_and_set_bit(int nr, volatile unsigned long *addr);
    int minix_set_bit(int nr, volatile unsigned long *addr);
    int minix_test_and_clear_bit(int nr, volatile unsigned long *addr);
    int minix_test_bit(int nr, const volatile unsigned long *addr);
    unsigned long minix_find_first_zero_bit(const unsigned long *addr,
    unsigned long size);

    In include/asm-generic/bitops/minix.h
    and include/asm-generic/bitops/minix-le.h

    This code largely copied from: include/asm-sparc/bitops.h

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • This patch introduces the C-language equivalents of the functions below:

    int ext2_set_bit_atomic(int nr, volatile unsigned long *addr);
    int ext2_clear_bit_atomic(int nr, volatile unsigned long *addr);

    In include/asm-generic/bitops/ext2-atomic.h

    This code largely copied from: include/asm-sparc/bitops.h

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • This patch introduces the C-language equivalents of the functions below:

    int ext2_set_bit(int nr, volatile unsigned long *addr);
    int ext2_clear_bit(int nr, volatile unsigned long *addr);
    int ext2_test_bit(int nr, const volatile unsigned long *addr);
    unsigned long ext2_find_first_zero_bit(const unsigned long *addr,
    unsigned long size);
    unsinged long ext2_find_next_zero_bit(const unsigned long *addr,
    unsigned long size);

    In include/asm-generic/bitops/ext2-non-atomic.h

    This code largely copied from:

    include/asm-powerpc/bitops.h
    include/asm-parisc/bitops.h

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • Build fix for s390 declare __u32 and __u64.

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • This patch introduces the C-language equivalents of the functions below:

    unsigned int hweight32(unsigned int w);
    unsigned int hweight16(unsigned int w);
    unsigned int hweight8(unsigned int w);
    unsigned long hweight64(__u64 w);

    In include/asm-generic/bitops/hweight.h

    This code largely copied from: include/linux/bitops.h

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • This patch introduces the C-language equivalent of the function: int ffs(int
    x);

    In include/asm-generic/bitops/ffs.h

    This code largely copied from: include/linux/bitops.h

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • This patch introduces the C-language equivalent of the function: int
    sched_find_first_bit(const unsigned long *b);

    In include/asm-generic/bitops/sched.h

    This code largely copied from: include/asm-powerpc/bitops.h

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • This patch introduces the C-language equivalents of the functions below:

    unsigned logn find_next_bit(const unsigned long *addr, unsigned long size,
    unsigned long offset);
    unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
    unsigned long offset);
    unsigned long find_first_zero_bit(const unsigned long *addr,
    unsigned long size);
    unsigned long find_first_bit(const unsigned long *addr, unsigned long size);

    In include/asm-generic/bitops/find.h

    This code largely copied from: arch/powerpc/lib/bitops.c

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • This patch introduces the C-language equivalent of the function: int
    fls64(__u64 x);

    In include/asm-generic/bitops/fls64.h

    This code largely copied from: include/linux/bitops.h

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • This patch introduces the C-language equivalent of the function: int fls(int
    x);

    In include/asm-generic/bitops/fls.h

    This code largely copied from: include/linux/bitops.h

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • This patch introduces the C-language equivalent of the function: unsigned long
    ffz(unsigned long word);

    In include/asm-generic/bitops/ffz.h

    This code largely copied from: include/asm-parisc/bitops.h

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • This patch introduces the C-language equivalent of the function: unsigned long
    __ffs(unsigned long word);

    In include/asm-generic/bitops/__ffs.h

    This code largely copied from: include/asm-sparc/bitops.h

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • This patch introduces the C-language equivalents of the functions below:

    void __set_bit(int nr, volatile unsigned long *addr);
    void __clear_bit(int nr, volatile unsigned long *addr);
    void __change_bit(int nr, volatile unsigned long *addr);
    int __test_and_set_bit(int nr, volatile unsigned long *addr);
    int __test_and_clear_bit(int nr, volatile unsigned long *addr);
    int __test_and_change_bit(int nr, volatile unsigned long *addr);
    int test_bit(int nr, const volatile unsigned long *addr);

    In include/asm-generic/bitops/non-atomic.h

    This code largely copied from: asm-powerpc/bitops.h

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita
     
  • This patch introduces the C-language equivalents of the functions below:

    void set_bit(int nr, volatile unsigned long *addr);
    void clear_bit(int nr, volatile unsigned long *addr);
    void change_bit(int nr, volatile unsigned long *addr);
    int test_and_set_bit(int nr, volatile unsigned long *addr);
    int test_and_clear_bit(int nr, volatile unsigned long *addr);
    int test_and_change_bit(int nr, volatile unsigned long *addr);

    In include/asm-generic/bitops/atomic.h

    This code largely copied from:

    include/asm-powerpc/bitops.h
    include/asm-parisc/bitops.h
    include/asm-parisc/atomic.h

    Signed-off-by: Akinobu Mita
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Akinobu Mita