lkml.org 
[lkml]   [2017]   [Apr]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[tip:smp/hotplug] x86/mtrr: Remove get_online_cpus() from mtrr_save_state()
    Commit-ID:  9ef0b62e7059e3ea85e2e5c4894bc2cb78b04eed
    Gitweb: http://git.kernel.org/tip/9ef0b62e7059e3ea85e2e5c4894bc2cb78b04eed
    Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
    AuthorDate: Tue, 18 Apr 2017 19:04:47 +0200
    Committer: Thomas Gleixner <tglx@linutronix.de>
    CommitDate: Thu, 20 Apr 2017 13:08:51 +0200

    x86/mtrr: Remove get_online_cpus() from mtrr_save_state()

    mtrr_save_state() is invoked from native_cpu_up() which is in the context
    of a CPU hotplug operation and therefor calling get_online_cpus() is
    pointless.

    While this works in the current get_online_cpus() implementation it
    prevents from converting the hotplug locking to percpu rwsems.

    Remove it.

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Steven Rostedt <rostedt@goodmis.org>
    Link: http://lkml.kernel.org/r/20170418170552.775914295@linutronix.de

    ---
    arch/x86/kernel/cpu/mtrr/main.c | 2 --
    1 file changed, 2 deletions(-)

    diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
    index 24e87e7..8fd1f8d 100644
    --- a/arch/x86/kernel/cpu/mtrr/main.c
    +++ b/arch/x86/kernel/cpu/mtrr/main.c
    @@ -807,10 +807,8 @@ void mtrr_save_state(void)
    if (!mtrr_enabled())
    return;

    - get_online_cpus();
    first_cpu = cpumask_first(cpu_online_mask);
    smp_call_function_single(first_cpu, mtrr_save_fixed_ranges, NULL, 1);
    - put_online_cpus();
    }

    void set_mtrr_aps_delayed_init(void)
    \
     
     \ /
      Last update: 2017-04-20 13:24    [W:4.294 / U:0.124 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site