lkml.org 
[lkml]   [2010]   [Jan]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[tip:core/ipi] generic-ipi: Optimize accesses by using DEFINE_PER_CPU_SHARED_ALIGNED for IPI data
    Commit-ID:  e03bcb68629c7f0728c95f1afe06ce48565c7713
    Gitweb: http://git.kernel.org/tip/e03bcb68629c7f0728c95f1afe06ce48565c7713
    Author: Milton Miller <miltonm@bga.com>
    AuthorDate: Mon, 18 Jan 2010 13:00:51 +1100
    Committer: Ingo Molnar <mingo@elte.hu>
    CommitDate: Mon, 18 Jan 2010 09:02:59 +0100

    generic-ipi: Optimize accesses by using DEFINE_PER_CPU_SHARED_ALIGNED for IPI data

    The smp ipi data is passed around and given write access by
    other cpus and should be separated from per-cpu data consumed by
    this cpu.

    Looking for hot lines, I saw call_function_data shared with
    tick_cpu_sched.

    Signed-off-by: Milton Miller <miltonm@bga.com>
    Acked-by: Anton Blanchard <anton@samba.org>
    Acked-by: Jens Axboe <jens.axboe@oracle.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: : Nick Piggin <npiggin@suse.de>
    LKML-Reference: <20100118020051.GR12666@kryten>
    Signed-off-by: Ingo Molnar <mingo@elte.hu>
    ---
    kernel/smp.c | 8 ++++----
    1 files changed, 4 insertions(+), 4 deletions(-)

    diff --git a/kernel/smp.c b/kernel/smp.c
    index f104084..9867b6b 100644
    --- a/kernel/smp.c
    +++ b/kernel/smp.c
    @@ -12,8 +12,6 @@
    #include <linux/smp.h>
    #include <linux/cpu.h>

    -static DEFINE_PER_CPU(struct call_single_queue, call_single_queue);
    -
    static struct {
    struct list_head queue;
    raw_spinlock_t lock;
    @@ -33,12 +31,14 @@ struct call_function_data {
    cpumask_var_t cpumask;
    };

    +static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_function_data, cfd_data);
    +
    struct call_single_queue {
    struct list_head list;
    raw_spinlock_t lock;
    };

    -static DEFINE_PER_CPU(struct call_function_data, cfd_data);
    +static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_single_queue, call_single_queue);

    static int
    hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
    @@ -256,7 +256,7 @@ void generic_smp_call_function_single_interrupt(void)
    }
    }

    -static DEFINE_PER_CPU(struct call_single_data, csd_data);
    +static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_single_data, csd_data);

    /*
    * smp_call_function_single - Run a function on a specific CPU

    \
     
     \ /
      Last update: 2010-01-19 15:27    [W:4.168 / U:0.216 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site