Eric Lee / smarc-fsl-linux-kernel

31 May, 2019

1 commit

  • 2874c5fd2   treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 ... Browse Code »

    Based on 1 normalized pattern(s):

    this program is free software you can redistribute it and or modify
    it under the terms of the gnu general public license as published by
    the free software foundation either version 2 of the license or at
    your option any later version

    extracted by the scancode license scanner the SPDX license identifier

    GPL-2.0-or-later

    has been chosen to replace the boilerplate/reference in 3029 file(s).

    Signed-off-by: Thomas Gleixner
    Reviewed-by: Allison Randal
    Cc: linux-spdx@vger.kernel.org
    Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
    Signed-off-by: Greg Kroah-Hartman

    Thomas Gleixner
     

07 Feb, 2018

1 commit

  • 0ade34c37   lib: optimize cpumask_next_and() ... Browse Code »

    We've measured that we spend ~0.6% of sys cpu time in cpumask_next_and().
    It's essentially a joined iteration in search for a non-zero bit, which is
    currently implemented as a lookup join (find a nonzero bit on the lhs,
    lookup the rhs to see if it's set there).

    Implement a direct join (find a nonzero bit on the incrementally built
    join). Also add generic bitmap benchmarks in the new `test_find_bit`
    module for new function (see `find_next_and_bit` in [2] and [3] below).

    For cpumask_next_and, direct benchmarking shows that it's 1.17x to 14x
    faster with a geometric mean of 2.1 on 32 CPUs [1]. No impact on memory
    usage. Note that on Arm, the new pure-C implementation still outperforms
    the old one that uses a mix of C and asm (`find_next_bit`) [3].

    [1] Approximate benchmark code:

    ```
    unsigned long src1p[nr_cpumask_longs] = {pattern1};
    unsigned long src2p[nr_cpumask_longs] = {pattern2};
    for (/*a bunch of repetitions*/) {
    for (int n = -1; n ]
    Link: http://lkml.kernel.org/r/1512556816-28627-1-git-send-email-geert@linux-m68k.org
    Link: http://lkml.kernel.org/r/20171128131334.23491-1-courbet@google.com
    Signed-off-by: Clement Courbet
    Signed-off-by: Geert Uytterhoeven
    Cc: Yury Norov
    Cc: Geert Uytterhoeven
    Cc: Alexey Dobriyan
    Cc: Rasmus Villemoes
    Signed-off-by: Andrew Morton

    Signed-off-by: Linus Torvalds

    Clement Courbet
     

25 Feb, 2017

1 commit

  • e4afd2e55   lib/find_bit.c: micro-optimise find_next_*_bit ... Browse Code »

    This saves 32 bytes on my x86-64 build, mostly due to alignment
    considerations and sharing more code between find_next_bit and
    find_next_zero_bit, but it does save a couple of instructions.

    There's really two parts to this commit:
    - First, the first half of the test: (!nbits || start >= nbits) is
    trivially a subset of the second half, since nbits and start are both
    unsigned
    - Second, while looking at the disassembly, I noticed that GCC was
    predicting the branch taken. Since this is a failure case, it's
    clearly the less likely of the two branches, so add an unlikely() to
    override GCC's heuristics.

    [mawilcox@microsoft.com: v2]
    Link: http://lkml.kernel.org/r/1483709016-1834-1-git-send-email-mawilcox@linuxonhyperv.com
    Link: http://lkml.kernel.org/r/1483709016-1834-1-git-send-email-mawilcox@linuxonhyperv.com
    Signed-off-by: Matthew Wilcox
    Acked-by: Yury Norov
    Acked-by: Rasmus Villemoes
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Matthew Wilcox
     

24 Oct, 2016

1 commit

  • 02bc11de5   tools lib: Add for_each_clear_bit macro ... Browse Code »

    Adding for_each_clear_bit macro plus all its the necessary backbone
    functions. Taken from related kernel code. It will be used in following
    patch.

    Signed-off-by: Jiri Olsa
    Cc: Adrian Hunter
    Cc: David Ahern
    Cc: Namhyung Kim
    Cc: Wang Nan
    Link: http://lkml.kernel.org/n/tip-cayv2zbqi0nlmg5sjjxs1775@git.kernel.org
    Signed-off-by: Arnaldo Carvalho de Melo

    Jiri Olsa
     

08 Jan, 2016

2 commits

  • 64af4e0da   tools lib: Sync tools/lib/find_bit.c with the kernel ... Browse Code »

    Need to move the bitmap.[ch] things from tools/perf/ to tools/lib, will
    be done in the next patches.

    Cc: Adrian Hunter
    Cc: Borislav Petkov
    Cc: David Ahern
    Cc: George Spelvin
    Cc: Namhyung Kim
    Cc: Rasmus Villemoes
    Cc: Wang Nan
    Cc: Yury Norov
    Link: http://lkml.kernel.org/n/tip-5fys65wkd7gu8j7a7xgukc5t@git.kernel.org
    Signed-off-by: Arnaldo Carvalho de Melo

    Arnaldo Carvalho de Melo
     
  • 552eb975b   tools lib: Move find_next_bit.c to tools/lib/ ... Browse Code »

    The commit that introduced it should've moved it to the same place, plus
    the 'tools/' prefix, but instead moved it to a bogus tools/lib/util/
    directory, being the only file there.

    Move it to tools/lib/find_bit.c, picking the name for the file where
    these routines live since:

    8f6f19dd5143 ("lib: move find_last_bit to lib/find_next_bit.c")

    Next step is to make tools/lib/find_bit.c to differ from lib/find_bit.c
    just in removing what is not used by tools/.

    Cc: Adrian Hunter
    Cc: Borislav Petkov
    Cc: David Ahern
    Cc: George Spelvin
    Cc: Namhyung Kim
    Cc: Rasmus Villemoes
    Cc: Wang Nan
    Cc: Yury Norov
    Link: http://lkml.kernel.org/n/tip-p391cex5mqvahp4pwrton87n@git.kernel.org
    Signed-off-by: Arnaldo Carvalho de Melo

    Arnaldo Carvalho de Melo