11 Feb, 2011

2 commits

  • Commit bb758e9637e5ddc removed snd_hrtimer_callback() from the hardware
    interrupt handler, thus moving it into a tasklet, but did not tell the
    ALSA timer framework about this, so the timer handling would now be done
    in the ALSA timer tasklet scheduled from another tasklet.

    To fix this, add the flag to tell the ALSA timer framework that the
    timer handler is already being invoked in a tasklet.

    Signed-off-by: Clemens Ladisch
    Signed-off-by: Takashi Iwai

    Clemens Ladisch
     
  • If a timer interrupt was delayed too much, hrtimer_forward_now() will
    forward the timer expiry more than once. When this happens, the
    additional number of elapsed ALSA timer ticks must be passed to
    snd_timer_interrupt() to prevent the ALSA timer from falling behind.

    This mostly fixes MIDI slowdown problems on highly-loaded systems with
    badly behaved interrupt handlers.

    Signed-off-by: Clemens Ladisch
    Reported-and-tested-by: Arthur Marsh
    Cc:
    Signed-off-by: Takashi Iwai

    Clemens Ladisch
     

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
     

11 Dec, 2009

1 commit

  • The timer stop callback can be called from snd_timer_interrupt(), which
    is called from the hrtimer callback. Since hrtimer_cancel() waits for
    the callback completion, this eventually results in a lock-up.

    This patch fixes the problem by just toggling a flag at stop callback
    and call hrtimer_cancel() later.

    Reported-and-tested-by: Wojtek Zabolotny
    Cc:
    Signed-off-by: Takashi Iwai

    Takashi Iwai
     

31 Dec, 2008

1 commit

  • …l/git/tip/linux-2.6-tip

    * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
    hrtimers: fix warning in kernel/hrtimer.c
    x86: make sure we really have an hpet mapping before using it
    x86: enable HPET on Fujitsu u9200
    linux/timex.h: cleanup for userspace
    posix-timers: simplify de_thread()->exit_itimers() path
    posix-timers: check ->it_signal instead of ->it_pid to validate the timer
    posix-timers: use "struct pid*" instead of "struct task_struct*"
    nohz: suppress needless timer reprogramming
    clocksource, acpi_pm.c: put acpi_pm_read_slow() under CONFIG_PCI
    nohz: no softirq pending warnings for offline cpus
    hrtimer: removing all ur callback modes, fix
    hrtimer: removing all ur callback modes, fix hotplug
    hrtimer: removing all ur callback modes
    x86: correct link to HPET timer specification
    rtc-cmos: export second NVRAM bank

    Fixed up conflicts in sound/drivers/pcsp/pcsp.c and sound/core/hrtimer.c
    manually.

    Linus Torvalds
     

08 Dec, 2008

2 commits


25 Oct, 2008

1 commit