lkml.org 
[lkml]   [2009]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[v5 RFC PATCH 3/7]: x86: refactor x86 idle power management code and remove all instances of pm_idle.
    * Arun R Bharadwaj <arun@linux.vnet.ibm.com> [2009-09-22 11:03:14]:

    This patch cleans up x86 of all instances of pm_idle.

    pm_idle which was earlier called from cpu_idle() idle loop
    is replaced by cpuidle_idle_call.

    x86 also registers to cpuidle when the idle routine is selected,
    by populating the cpuidle_device data structure for each cpu.

    This is replicated for apm module and for xen, which also used pm_idle.


    Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com>
    ---
    arch/x86/kernel/apm_32.c | 37 +++++++++++++++++++++--
    arch/x86/kernel/process.c | 69 ++++++++++++++++++++++++++++++++++---------
    arch/x86/kernel/process_32.c | 3 +
    arch/x86/kernel/process_64.c | 3 +
    arch/x86/xen/setup.c | 22 +++++++++++++
    5 files changed, 114 insertions(+), 20 deletions(-)

    Index: linux.trees.git/arch/x86/kernel/process.c
    ===================================================================
    --- linux.trees.git.orig/arch/x86/kernel/process.c
    +++ linux.trees.git/arch/x86/kernel/process.c
    @@ -9,6 +9,8 @@
    #include <linux/pm.h>
    #include <linux/clockchips.h>
    #include <linux/random.h>
    +#include <linux/cpuidle.h>
    +
    #include <trace/power.h>
    #include <asm/system.h>
    #include <asm/apic.h>
    @@ -247,12 +249,6 @@ int sys_vfork(struct pt_regs *regs)
    unsigned long boot_option_idle_override = 0;
    EXPORT_SYMBOL(boot_option_idle_override);

    -/*
    - * Powermanagement idle function, if any..
    - */
    -void (*pm_idle)(void);
    -EXPORT_SYMBOL(pm_idle);
    -
    #ifdef CONFIG_X86_32
    /*
    * This halt magic was a workaround for ancient floppy DMA
    @@ -531,15 +527,58 @@ static void c1e_idle(void)
    default_idle();
    }

    +static void (*local_idle)(void);
    +DEFINE_PER_CPU(struct cpuidle_device, idle_devices);
    +
    +struct cpuidle_driver cpuidle_default_driver = {
    + .name = "cpuidle_default",
    +};
    +
    +static int local_idle_loop(struct cpuidle_device *dev, struct cpuidle_state *st)
    +{
    + ktime_t t1, t2;
    + s64 diff;
    + int ret;
    +
    + t1 = ktime_get();
    + local_idle();
    + t2 = ktime_get();
    +
    + diff = ktime_to_us(ktime_sub(t2, t1));
    + if (diff > INT_MAX)
    + diff = INT_MAX;
    + ret = (int) diff;
    +
    + return ret;
    +}
    +static int __cpuinit setup_cpuidle_simple(void)
    +{
    + struct cpuidle_device *dev;
    + int cpu;
    +
    + if (!cpuidle_curr_driver)
    + cpuidle_register_driver(&cpuidle_default_driver);
    +
    + for_each_online_cpu(cpu) {
    + dev = &per_cpu(idle_devices, cpu);
    + dev->cpu = cpu;
    + dev->states[0].enter = local_idle_loop;
    + dev->state_count = 1;
    + cpuidle_register_device(dev);
    + }
    + return 0;
    +}
    +late_initcall(setup_cpuidle_simple);
    +
    void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
    {
    #ifdef CONFIG_SMP
    - if (pm_idle == poll_idle && smp_num_siblings > 1) {
    + if (local_idle == poll_idle && smp_num_siblings > 1) {
    printk(KERN_WARNING "WARNING: polling idle and HT enabled,"
    " performance may degrade.\n");
    }
    #endif
    - if (pm_idle)
    + if (local_idle)
    return;

    if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) {
    @@ -547,18 +586,20 @@ void __cpuinit select_idle_routine(const
    * One CPU supports mwait => All CPUs supports mwait
    */
    printk(KERN_INFO "using mwait in idle threads.\n");
    - pm_idle = mwait_idle;
    + local_idle = mwait_idle;
    } else if (check_c1e_idle(c)) {
    printk(KERN_INFO "using C1E aware idle routine\n");
    - pm_idle = c1e_idle;
    + local_idle = c1e_idle;
    } else
    - pm_idle = default_idle;
    + local_idle = default_idle;
    +
    + return;
    }

    void __init init_c1e_mask(void)
    {
    /* If we're using c1e_idle, we need to allocate c1e_mask. */
    - if (pm_idle == c1e_idle) {
    + if (local_idle == c1e_idle) {
    alloc_cpumask_var(&c1e_mask, GFP_KERNEL);
    cpumask_clear(c1e_mask);
    }
    @@ -571,7 +612,7 @@ static int __init idle_setup(char *str)

    if (!strcmp(str, "poll")) {
    printk("using polling idle threads.\n");
    - pm_idle = poll_idle;
    + local_idle = poll_idle;
    } else if (!strcmp(str, "mwait"))
    force_mwait = 1;
    else if (!strcmp(str, "halt")) {
    @@ -582,7 +623,7 @@ static int __init idle_setup(char *str)
    * To continue to load the CPU idle driver, don't touch
    * the boot_option_idle_override.
    */
    - pm_idle = default_idle;
    + local_idle = default_idle;
    idle_halt = 1;
    return 0;
    } else if (!strcmp(str, "nomwait")) {
    Index: linux.trees.git/arch/x86/kernel/process_32.c
    ===================================================================
    --- linux.trees.git.orig/arch/x86/kernel/process_32.c
    +++ linux.trees.git/arch/x86/kernel/process_32.c
    @@ -40,6 +40,7 @@
    #include <linux/uaccess.h>
    #include <linux/io.h>
    #include <linux/kdebug.h>
    +#include <linux/cpuidle.h>

    #include <asm/pgtable.h>
    #include <asm/system.h>
    @@ -113,7 +114,7 @@ void cpu_idle(void)
    local_irq_disable();
    /* Don't trace irqs off for idle */
    stop_critical_timings();
    - pm_idle();
    + cpuidle_idle_call();
    start_critical_timings();
    }
    tick_nohz_restart_sched_tick();
    Index: linux.trees.git/arch/x86/kernel/process_64.c
    ===================================================================
    --- linux.trees.git.orig/arch/x86/kernel/process_64.c
    +++ linux.trees.git/arch/x86/kernel/process_64.c
    @@ -39,6 +39,7 @@
    #include <linux/io.h>
    #include <linux/ftrace.h>
    #include <linux/dmi.h>
    +#include <linux/cpuidle.h>

    #include <asm/pgtable.h>
    #include <asm/system.h>
    @@ -142,7 +143,7 @@ void cpu_idle(void)
    enter_idle();
    /* Don't trace irqs off for idle */
    stop_critical_timings();
    - pm_idle();
    + cpuidle_idle_call();
    start_critical_timings();
    /* In many cases the interrupt that ended idle
    has already called exit_idle. But some idle
    Index: linux.trees.git/arch/x86/kernel/apm_32.c
    ===================================================================
    --- linux.trees.git.orig/arch/x86/kernel/apm_32.c
    +++ linux.trees.git/arch/x86/kernel/apm_32.c
    @@ -2257,6 +2257,38 @@ static struct dmi_system_id __initdata a
    { }
    };

    +DEFINE_PER_CPU(struct cpuidle_device, apm_idle_devices);
    +
    +struct cpuidle_driver cpuidle_apm_driver = {
    + .name = "cpuidle_apm",
    +};
    +
    +void __cpuinit setup_cpuidle_apm(void)
    +{
    + struct cpuidle_device *dev;
    +
    + if (!cpuidle_curr_driver)
    + cpuidle_register_driver(&cpuidle_apm_driver);
    +
    + dev = &per_cpu(apm_idle_devices, smp_processor_id());
    + dev->cpu = smp_processor_id();
    + dev->states[0].enter = apm_cpu_idle;
    + dev->state_count = 1;
    + cpuidle_register_device(dev);
    +}
    +
    +void exit_cpuidle_apm(void)
    +{
    + struct cpuidle_device *dev;
    + int cpu;
    +
    + for_each_online_cpu(cpu) {
    + dev = &per_cpu(apm_idle_devices, cpu);
    + cpuidle_unregister_device(dev);
    + }
    +}
    +
    +
    /*
    * Just start the APM thread. We do NOT want to do APM BIOS
    * calls from anything but the APM thread, if for no other reason
    @@ -2394,8 +2426,7 @@ static int __init apm_init(void)
    if (HZ != 100)
    idle_period = (idle_period * HZ) / 100;
    if (idle_threshold < 100) {
    - original_pm_idle = pm_idle;
    - pm_idle = apm_cpu_idle;
    + setup_cpuidle_apm();
    set_pm_idle = 1;
    }

    @@ -2407,7 +2438,7 @@ static void __exit apm_exit(void)
    int error;

    if (set_pm_idle) {
    - pm_idle = original_pm_idle;
    + exit_cpuidle_apm();
    /*
    * We are about to unload the current idle thread pm callback
    * (pm_idle), Wait for all processors to update cached/local
    Index: linux.trees.git/arch/x86/xen/setup.c
    ===================================================================
    --- linux.trees.git.orig/arch/x86/xen/setup.c
    +++ linux.trees.git/arch/x86/xen/setup.c
    @@ -8,6 +8,7 @@
    #include <linux/sched.h>
    #include <linux/mm.h>
    #include <linux/pm.h>
    +#include <linux/cpuidle.h>

    #include <asm/elf.h>
    #include <asm/vdso.h>
    @@ -151,6 +152,25 @@ void __cpuinit xen_enable_syscall(void)
    #endif /* CONFIG_X86_64 */
    }

    +DEFINE_PER_CPU(struct cpuidle_device, idle_devices);
    +struct cpuidle_driver cpuidle_xen_driver = {
    + .name = "cpuidle_xen",
    +};
    +
    +void __cpuinit setup_cpuidle_xen(void)
    +{
    + struct cpuidle_device *dev;
    +
    + if (!cpuidle_curr_driver)
    + cpuidle_register_driver(&cpuidle_xen_driver);
    +
    + dev = &per_cpu(idle_devices, smp_processor_id());
    + dev->cpu = smp_processor_id();
    + dev->states[0].enter = xen_idle;
    + dev->state_count = 1;
    + cpuidle_register_device(dev);
    +}
    +
    void __init xen_arch_setup(void)
    {
    struct physdev_set_iopl set_iopl;
    @@ -186,7 +206,7 @@ void __init xen_arch_setup(void)
    MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
    COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);

    - pm_idle = xen_idle;
    + setup_cpuidle_xen();

    paravirt_disable_iospace();


    \
     
     \ /
      Last update: 2009-09-22 07:39    [W:0.054 / U:0.072 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site