lkml.org 
[lkml]   [2008]   [Nov]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[RFC patch 01/18] get_cycles() : kconfig HAVE_GET_CYCLES
    Create a new "HAVE_GET_CYCLES" architecture option to specify which
    architectures provide 64-bits TSC counters readable with get_cycles(). It's
    principally useful to only enable high-precision tracing code only on such
    architectures and don't even bother building it on architectures which lack such
    support.

    It also requires architectures to provide get_cycles_barrier() and
    get_cycles_rate().

    I mainly use it for the "priority-sifting rwlock" latency tracing code, which
    traces worse-case latency induced by the locking. It also provides the basic
    changes needed for the LTTng timestamping infrastructure.

    Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
    CC: David Miller <davem@davemloft.net>
    CC: Linus Torvalds <torvalds@linux-foundation.org>
    CC: Andrew Morton <akpm@linux-foundation.org>
    CC: Ingo Molnar <mingo@redhat.com>
    CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
    CC: Thomas Gleixner <tglx@linutronix.de>
    CC: Steven Rostedt <rostedt@goodmis.org>
    CC: linux-arch@vger.kernel.org
    ---
    init/Kconfig | 10 ++++++++++
    1 file changed, 10 insertions(+)

    Index: linux.trees.git/init/Kconfig
    ===================================================================
    --- linux.trees.git.orig/init/Kconfig 2008-11-07 00:06:07.000000000 -0500
    +++ linux.trees.git/init/Kconfig 2008-11-07 00:07:23.000000000 -0500
    @@ -330,6 +330,16 @@ config CPUSETS
    config HAVE_UNSTABLE_SCHED_CLOCK
    bool

    +#
    +# Architectures with a 64-bits get_cycles() should select this.
    +# They should also define
    +# get_cycles_barrier() : instruction synchronization barrier if required
    +# get_cycles_rate() : cycle counter rate, in HZ. If 0, TSC are not synchronized
    +# across CPUs or their frequency may vary due to frequency scaling.
    +#
    +config HAVE_GET_CYCLES
    + def_bool n
    +
    config GROUP_SCHED
    bool "Group CPU scheduler"
    depends on EXPERIMENTAL
    --
    Mathieu Desnoyers
    OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68


    \
     
     \ /
      Last update: 2008-11-07 06:53    [W:0.022 / U:59.552 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site