Eric Lee / smarc-fsl-linux-kernel

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
     

12 Oct, 2016

1 commit

  • 26b5679e4   relay: Use irq_work instead of plain timer for deferred wakeup ... Browse Code »

    Relay avoids calling wake_up_interruptible() for doing the wakeup of
    readers/consumers, waiting for the generation of new data, from the
    context of a process which produced the data. This is apparently done to
    prevent the possibility of a deadlock in case Scheduler itself is is
    generating data for the relay, after acquiring rq->lock.

    The following patch used a timer (to be scheduled at next jiffy), for
    delegating the wakeup to another context.
    commit 7c9cb38302e78d24e37f7d8a2ea7eed4ae5f2fa7
    Author: Tom Zanussi
    Date: Wed May 9 02:34:01 2007 -0700

    relay: use plain timer instead of delayed work

    relay doesn't need to use schedule_delayed_work() for waking readers
    when a simple timer will do.

    Scheduling a plain timer, at next jiffies boundary, to do the wakeup
    causes a significant wakeup latency for the Userspace client, which makes
    relay less suitable for the high-frequency low-payload use cases where the
    data gets generated at a very high rate, like multiple sub buffers getting
    filled within a milli second. Moreover the timer is re-scheduled on every
    newly produced sub buffer so the timer keeps getting pushed out if sub
    buffers are filled in a very quick succession (less than a jiffy gap
    between filling of 2 sub buffers). As a result relay runs out of sub
    buffers to store the new data.

    By using irq_work it is ensured that wakeup of userspace client, blocked
    in the poll call, is done at earliest (through self IPI or next timer
    tick) enabling it to always consume the data in time. Also this makes
    relay consistent with printk & ring buffers (trace), as they too use
    irq_work for deferred wake up of readers.

    [arnd@arndb.de: select CONFIG_IRQ_WORK]
    Link: http://lkml.kernel.org/r/20160912154035.3222156-1-arnd@arndb.de
    [akpm@linux-foundation.org: coding-style fixes]
    Link: http://lkml.kernel.org/r/1472906487-1559-1-git-send-email-akash.goel@intel.com
    Signed-off-by: Peter Zijlstra
    Signed-off-by: Akash Goel
    Cc: Tom Zanussi
    Cc: Chris Wilson
    Cc: Tvrtko Ursulin
    Signed-off-by: Arnd Bergmann
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Peter Zijlstra
     

07 Sep, 2016

2 commits

  • e6d4989a9   relayfs: Convert to hotplug state machine ... Browse Code »

    Install the callbacks via the state machine. They are installed at run time but
    relay_prepare_cpu() does not need to be invoked by the boot CPU because
    relay_open() was not yet invoked and there are no pools that need to be created.

    Signed-off-by: Richard Weinberger
    Signed-off-by: Thomas Gleixner
    Signed-off-by: Sebastian Andrzej Siewior
    Reviewed-by: Sebastian Andrzej Siewior
    Cc: Peter Zijlstra
    Cc: rt@linutronix.de
    Cc: Andrew Morton
    Link: http://lkml.kernel.org/r/20160818125731.27256-3-bigeasy@linutronix.de
    Signed-off-by: Thomas Gleixner

    Richard Weinberger
     
  • 017c59c04   relay: Use per CPU constructs for the relay channel buffer pointers ... Browse Code »

    relay essentially needs to maintain a per CPU array of channel buffer
    pointers but it manually creates that array. Instead its better to use
    the per CPU constructs, provided by the kernel, to allocate & access the
    array of pointer to channel buffers.

    Signed-off-by: Akash Goel
    Reviewed-by: Chris Wilson
    Link: http://lkml.kernel.org/r/1470909140-25919-1-git-send-email-akash.goel@intel.com
    Signed-off-by: Andrew Morton
    Signed-off-by: Thomas Gleixner

    Akash Goel
     

01 May, 2013

1 commit

05 Mar, 2012

1 commit

  • 187f1882b   BUG: headers with BUG/BUG_ON etc. need linux/bug.h ... Browse Code »

    If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any
    other BUG variant in a static inline (i.e. not in a #define) then
    that header really should be including and not just
    expecting it to be implicitly present.

    We can make this change risk-free, since if the files using these
    headers didn't have exposure to linux/bug.h already, they would have
    been causing compile failures/warnings.

    Signed-off-by: Paul Gortmaker

    Paul Gortmaker
     

04 Jan, 2012

1 commit

24 Sep, 2009

1 commit

27 Jul, 2008

1 commit

  • 20d8b67c0   relay: add buffer-only channels; useful for early logging ... Browse Code »

    Allows one to create and use a channel with no associated files. Files
    can be initialized later. This is useful in scenarios such as logging in
    early code, before VFS is up. Therefore, such channels can be created and
    used as soon as kmem_cache_init() completed.

    This is needed by kmemtrace to do tracing in early kernel code.

    [kosaki.motohiro@jp.fujitsu.com: build fix]
    Signed-off-by: Eduard - Gabriel Munteanu
    Cc: Tom Zanussi
    Signed-off-by: KOSAKI Motohiro
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Eduard - Gabriel Munteanu
     

10 May, 2007

1 commit

12 Feb, 2007

1 commit

  • 23c887522   [PATCH] Relay: add CPU hotplug support ... Browse Code »

    Mathieu originally needed to add this for tracing Xen, but it's something
    that's needed for any application that can be tracing while cpus are added.

    unplug isn't supported by this patch. The thought was that at minumum a new
    buffer needs to be added when a cpu comes up, but it wasn't worth the effort
    to remove buffers on cpu down since they'd be freed soon anyway when the
    channel was closed.

    [zanussi@us.ibm.com: avoid lock_cpu_hotplug deadlock]
    Signed-off-by: Mathieu Desnoyers
    Cc: Tom Zanussi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mathieu Desnoyers
     

08 Dec, 2006

1 commit

22 Nov, 2006

1 commit

26 Apr, 2006

1 commit

24 Mar, 2006

1 commit