lkml.org 
[lkml]   [2016]   [May]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[tip:smp/hotplug] sched/hotplug: Make activate() the last hotplug step
    Commit-ID:  b4f43a28647291a7dc1773924b77bc5ee7eccb16
    Gitweb: http://git.kernel.org/tip/b4f43a28647291a7dc1773924b77bc5ee7eccb16
    Author: Thomas Gleixner <tglx@linutronix.de>
    AuthorDate: Thu, 10 Mar 2016 12:54:19 +0100
    Committer: Thomas Gleixner <tglx@linutronix.de>
    CommitDate: Thu, 5 May 2016 13:17:54 +0200

    sched/hotplug: Make activate() the last hotplug step

    The scheduler can handle per cpu threads before the cpu is set to active and
    it does not allow user space threads on the cpu before active is
    set. Attaching to the scheduling domains is also not required before user
    space threads can be handled.

    Move the activation to the end of the hotplug state space. That also means
    that deactivation is the first action when a cpu is shut down.

    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Acked-by: Peter Zijlstra <peterz@infradead.org>
    Cc: rt@linutronix.de
    Link: http://lkml.kernel.org/r/20160310120025.597477199@linutronix.de
    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

    ---
    include/linux/cpuhotplug.h | 2 +-
    kernel/cpu.c | 13 +++++++------
    2 files changed, 8 insertions(+), 7 deletions(-)

    diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
    index 9e07468..386374d 100644
    --- a/include/linux/cpuhotplug.h
    +++ b/include/linux/cpuhotplug.h
    @@ -13,11 +13,11 @@ enum cpuhp_state {
    CPUHP_AP_ONLINE,
    CPUHP_TEARDOWN_CPU,
    CPUHP_AP_ONLINE_IDLE,
    - CPUHP_AP_ACTIVE,
    CPUHP_AP_SMPBOOT_THREADS,
    CPUHP_AP_NOTIFY_ONLINE,
    CPUHP_AP_ONLINE_DYN,
    CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30,
    + CPUHP_AP_ACTIVE,
    CPUHP_ONLINE,
    };

    diff --git a/kernel/cpu.c b/kernel/cpu.c
    index d6eeb8c..6180dd6 100644
    --- a/kernel/cpu.c
    +++ b/kernel/cpu.c
    @@ -1242,12 +1242,6 @@ static struct cpuhp_step cpuhp_ap_states[] = {
    [CPUHP_AP_ONLINE] = {
    .name = "ap:online",
    },
    - /* First state is scheduler control. Interrupts are enabled */
    - [CPUHP_AP_ACTIVE] = {
    - .name = "sched:active",
    - .startup = sched_cpu_activate,
    - .teardown = sched_cpu_deactivate,
    - },
    /* Handle smpboot threads park/unpark */
    [CPUHP_AP_SMPBOOT_THREADS] = {
    .name = "smpboot:threads",
    @@ -1269,6 +1263,13 @@ static struct cpuhp_step cpuhp_ap_states[] = {
    * The dynamically registered state space is here
    */

    + /* Last state is scheduler control setting the cpu active */
    + [CPUHP_AP_ACTIVE] = {
    + .name = "sched:active",
    + .startup = sched_cpu_activate,
    + .teardown = sched_cpu_deactivate,
    + },
    +
    /* CPU is fully up and running. */
    [CPUHP_ONLINE] = {
    .name = "online",
    \
     
     \ /
      Last update: 2016-05-05 13:41    [W:4.165 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site