Eric Lee / smarc-fsl-linux-kernel

16 Nov, 2017

1 commit

  • 7d5905dc1   x86 / CPU: Always show current CPU frequency in /proc/cpuinfo ... Browse Code »

    After commit 890da9cf0983 (Revert "x86: do not use cpufreq_quick_get()
    for /proc/cpuinfo "cpu MHz"") the "cpu MHz" number in /proc/cpuinfo
    on x86 can be either the nominal CPU frequency (which is constant)
    or the frequency most recently requested by a scaling governor in
    cpufreq, depending on the cpufreq configuration. That is somewhat
    inconsistent and is different from what it was before 4.13, so in
    order to restore the previous behavior, make it report the current
    CPU frequency like the scaling_cur_freq sysfs file in cpufreq.

    To that end, modify the /proc/cpuinfo implementation on x86 to use
    aperfmperf_snapshot_khz() to snapshot the APERF and MPERF feedback
    registers, if available, and use their values to compute the CPU
    frequency to be reported as "cpu MHz".

    However, do that carefully enough to avoid accumulating delays that
    lead to unacceptable access times for /proc/cpuinfo on systems with
    many CPUs. Run aperfmperf_snapshot_khz() once on all CPUs
    asynchronously at the /proc/cpuinfo open time, add a single delay
    upfront (if necessary) at that point and simply compute the current
    frequency while running show_cpuinfo() for each individual CPU.

    Also, to avoid slowing down /proc/cpuinfo accesses too much, reduce
    the default delay between consecutive APERF and MPERF reads to 10 ms,
    which should be sufficient to get large enough numbers for the
    frequency computation in all cases.

    Fixes: 890da9cf0983 (Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"")
    Signed-off-by: Rafael J. Wysocki
    Acked-by: Thomas Gleixner
    Tested-by: Thomas Gleixner
    Acked-by: Ingo Molnar

    Rafael J. Wysocki
     

02 Nov, 2017

1 commit

  • b24413180   License cleanup: add SPDX GPL-2.0 license identifier to files with no license ... Browse Code »

    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
     

24 Jan, 2014

1 commit

  • abaf3787a   fs/proc: don't use module_init for non-modular core code ... Browse Code »

    PROC_FS is a bool, so this code is either present or absent. It will
    never be modular, so using module_init as an alias for __initcall is
    rather misleading.

    Fix this up now, so that we can relocate module_init from init.h into
    module.h in the future. If we don't do this, we'd have to add module.h to
    obviously non-modular code, and that would be ugly at best.

    Note that direct use of __initcall is discouraged, vs. one of the
    priority categorized subgroups. As __initcall gets mapped onto
    device_initcall, our use of fs_initcall (which makes sense for fs code)
    will thus change these registrations from level 6-device to level 5-fs
    (i.e. slightly earlier). However no observable impact of that small
    difference has been observed during testing, or is expected.

    Also note that this change uncovers a missing semicolon bug in the
    registration of vmcore_init as an initcall.

    Signed-off-by: Paul Gortmaker
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Paul Gortmaker
     

23 Oct, 2008

1 commit