lkml.org 
[lkml]   [2012]   [Jan]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[v7 1/8] smp: introduce a generic on_each_cpu_mask function
    Date
    on_each_cpu_mask calls a function on processors specified by
    cpumask, which may or may not include the local processor.

    You must not call this function with disabled interrupts or
    from a hardware interrupt handler or from a bottom half handler.

    Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
    Reviewed-by: Christoph Lameter <cl@linux.com>
    CC: Chris Metcalf <cmetcalf@tilera.com>
    CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
    CC: Frederic Weisbecker <fweisbec@gmail.com>
    CC: Russell King <linux@arm.linux.org.uk>
    CC: linux-mm@kvack.org
    CC: Pekka Enberg <penberg@kernel.org>
    CC: Matt Mackall <mpm@selenic.com>
    CC: Rik van Riel <riel@redhat.com>
    CC: Andi Kleen <andi@firstfloor.org>
    CC: Sasha Levin <levinsasha928@gmail.com>
    CC: Mel Gorman <mel@csn.ul.ie>
    CC: Andrew Morton <akpm@linux-foundation.org>
    CC: Alexander Viro <viro@zeniv.linux.org.uk>
    CC: linux-fsdevel@vger.kernel.org
    CC: Avi Kivity <avi@redhat.com>
    CC: Michal Nazarewicz <mina86@mina86.org>
    CC: Kosaki Motohiro <kosaki.motohiro@gmail.com>
    CC: Milton Miller <miltonm@bga.com>
    ---
    include/linux/smp.h | 22 ++++++++++++++++++++++
    kernel/smp.c | 29 +++++++++++++++++++++++++++++
    2 files changed, 51 insertions(+), 0 deletions(-)

    diff --git a/include/linux/smp.h b/include/linux/smp.h
    index 8cc38d3..d0adb78 100644
    --- a/include/linux/smp.h
    +++ b/include/linux/smp.h
    @@ -102,6 +102,13 @@ static inline void call_function_init(void) { }
    int on_each_cpu(smp_call_func_t func, void *info, int wait);

    /*
    + * Call a function on processors specified by mask, which might include
    + * the local one.
    + */
    +void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
    + void *info, bool wait);
    +
    +/*
    * Mark the boot cpu "online" so that it can call console drivers in
    * printk() and can access its per-cpu storage.
    */
    @@ -132,6 +139,21 @@ static inline int up_smp_call_function(smp_call_func_t func, void *info)
    local_irq_enable(); \
    0; \
    })
    +/*
    + * Note we still need to test the mask even for UP
    + * because we actually can get an empty mask from
    + * code that on SMP might call us without the local
    + * CPU in the mask.
    + */
    +#define on_each_cpu_mask(mask, func, info, wait) \
    + do { \
    + if (cpumask_test_cpu(0, (mask))) { \
    + local_irq_disable(); \
    + (func)(info); \
    + local_irq_enable(); \
    + } \
    + } while (0)
    +
    static inline void smp_send_reschedule(int cpu) { }
    #define num_booting_cpus() 1
    #define smp_prepare_boot_cpu() do {} while (0)
    diff --git a/kernel/smp.c b/kernel/smp.c
    index db197d6..a081e6c 100644
    --- a/kernel/smp.c
    +++ b/kernel/smp.c
    @@ -701,3 +701,32 @@ int on_each_cpu(void (*func) (void *info), void *info, int wait)
    return ret;
    }
    EXPORT_SYMBOL(on_each_cpu);
    +
    +/**
    + * on_each_cpu_mask(): Run a function on processors specified by
    + * cpumask, which may include the local processor.
    + * @mask: The set of cpus to run on (only runs on online subset).
    + * @func: The function to run. This must be fast and non-blocking.
    + * @info: An arbitrary pointer to pass to the function.
    + * @wait: If true, wait (atomically) until function has completed
    + * on other CPUs.
    + *
    + * If @wait is true, then returns once @func has returned.
    + *
    + * You must not call this function with disabled interrupts or
    + * from a hardware interrupt handler or from a bottom half handler.
    + */
    +void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
    + void *info, bool wait)
    +{
    + int cpu = get_cpu();
    +
    + smp_call_function_many(mask, func, info, wait);
    + if (cpumask_test_cpu(cpu, mask)) {
    + local_irq_disable();
    + func(info);
    + local_irq_enable();
    + }
    + put_cpu();
    +}
    +EXPORT_SYMBOL(on_each_cpu_mask);
    --
    1.7.0.4


    \
     
     \ /
      Last update: 2012-01-26 11:05    [W:0.028 / U:29.572 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site