lkml.org 
[lkml]   [2009]   [Aug]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: Subject:[ PATCH 001:003] OFFSCHED CORE
    From
    Date
    raz ben yehuda <raziebe@gmail.com> writes:

    > OFFSCHED support.
    >
    > . A callback invoked just before halting the processor.
    > . SMP alternative work-around. we do not run smp alternatives if we are
    > left with a single processor.
    > . A set of utilities used by the offsched driver.

    Nacked-by: "Eric W. Biederman" <ebiederm@xmission.com>


    Cpu hotunplug is mostly broken when it comes to irqs.
    Building on and extending broken code is just asking for trouble,
    especially for out of tree code.

    > process.c | 109 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    > smpboot.c | 13 +++++--
    > 2 files changed, 118 insertions(+), 4 deletions(-)
    >
    > Signed-off-by: raziebe@gmail.com
    > ---
    > diff -X 2.6.30-offsched/Documentation/dontdiff -urN tmp/linux-2.6.30/arch/x86/kernel/process.c 2.6.30-offsched/arch/x86/kernel/process.c
    > --- tmp/linux-2.6.30/arch/x86/kernel/process.c 2009-06-10 06:05:27.000000000 +0300
    > +++ 2.6.30-offsched/arch/x86/kernel/process.c 2009-08-21 22:02:44.000000000 +0300
    > @@ -613,3 +613,112 @@
    > }
    > early_param("idle", idle_setup);
    >
    > +#ifdef CONFIG_HOTPLUG_CPU
    > +struct hotplug_cpu{
    > + long flags;
    > + void (*hotplug_cpu_dead)(void);
    > +};
    > +
    > +static long offsched_services;
    > +
    > +#define CPU_OFFSCHED 31
    > +#define CPU_OFFSCHED_KMEM 30
    > +#define SERVICE_TIMER 01
    > +#define SERVICE_NAPI 02
    > +
    > +DEFINE_PER_CPU(struct hotplug_cpu, offschedcpu);
    > +
    > +void unregister_offsched(int cpuid)
    > +{
    > + struct hotplug_cpu *cpu = &per_cpu(offschedcpu, cpuid);
    > + cpu->hotplug_cpu_dead = NULL;
    > + clear_bit(CPU_OFFSCHED, &cpu->flags);
    > +}
    > +EXPORT_SYMBOL_GPL(unregister_offsched);
    > +
    > +int is_offsched(int cpuid)
    > +{
    > + struct hotplug_cpu *cpu = &per_cpu(offschedcpu, cpuid);
    > + return test_bit(CPU_OFFSCHED, &cpu->flags);
    > +}
    > +EXPORT_SYMBOL_GPL(is_offsched);
    > +
    > +int is_offsched_kmem(int cpuid)
    > +{
    > + struct hotplug_cpu *cpu = &per_cpu(offschedcpu, cpuid);
    > + return test_bit(CPU_OFFSCHED_KMEM, &cpu->flags);
    > +}
    > +EXPORT_SYMBOL_GPL(is_offsched_kmem);
    > +
    > +void set_offsched_kmem(int cpuid)
    > +{
    > + struct hotplug_cpu *cpu = &per_cpu(offschedcpu, cpuid);
    > + set_bit(CPU_OFFSCHED_KMEM, &cpu->flags);
    > +}
    > +EXPORT_SYMBOL_GPL(set_offsched_kmem);
    > +
    > +void unset_offsched_kmem(int cpuid)
    > +{
    > + struct hotplug_cpu *cpu = &per_cpu(offschedcpu, cpuid);
    > + clear_bit(CPU_OFFSCHED_KMEM, &cpu->flags);
    > +}
    > +EXPORT_SYMBOL_GPL(unset_offsched_kmem);
    > +
    > +int register_offsched(void (*offsched_callback)(void), int cpuid)
    > +{
    > + struct hotplug_cpu *cpu = &per_cpu(offschedcpu, cpuid);
    > + if (is_offsched(cpuid))
    > + return -1;
    > + cpu->hotplug_cpu_dead = offsched_callback;
    > + set_bit(CPU_OFFSCHED, &cpu->flags);
    > + return 0;
    > +}
    > +EXPORT_SYMBOL_GPL(register_offsched);
    > +
    > +void run_offsched(void)
    > +{
    > + int cpuid = raw_smp_processor_id();
    > + struct hotplug_cpu *cpu = &per_cpu(offschedcpu, cpuid);
    > + cpu->hotplug_cpu_dead();
    > +}
    > +
    > +int offsched_is_napi_avail(void)
    > +{
    > + return SERVICE_NAPI & offsched_services;
    > +}
    > +
    > +int (*offsched_rule)(void *);
    > +EXPORT_SYMBOL(offsched_rule);
    > +/*
    > +* if we a have filter than apply filter.
    > +* return 0 if packet should go to kernel
    > +* return 1 if packet should go to offsched.
    > +*/
    > +int offsched_pkt(void *s)
    > +{
    > + if (offsched_rule)
    > + return offsched_rule(s);
    > + return 0;
    > +}
    > +
    > +void offsched_register_napi(void)
    > +{
    > + offsched_services |= SERVICE_NAPI;
    > +}
    > +EXPORT_SYMBOL_GPL(offsched_register_napi);
    > +
    > +void offsched_unregister_napi(void)
    > +{
    > + offsched_services &= ~SERVICE_NAPI;
    > +}
    > +EXPORT_SYMBOL_GPL(offsched_unregister_napi);
    > +
    > +/*
    > + * napi scheudule is called in offsched context.
    > +*/
    > +void offsched_napi_schedule(void *n)
    > +{
    > +
    > +}
    > +
    > +#endif
    > diff -X 2.6.30-offsched/Documentation/dontdiff -urN tmp/linux-2.6.30/arch/x86/kernel/smpboot.c 2.6.30-offsched/arch/x86/kernel/smpboot.c
    > --- tmp/linux-2.6.30/arch/x86/kernel/smpboot.c 2009-06-10 06:05:27.000000000 +0300
    > +++ 2.6.30-offsched/arch/x86/kernel/smpboot.c 2009-07-25 13:59:19.000000000 +0300
    > @@ -39,6 +39,8 @@
    > * Glauber Costa : i386 and x86_64 integration
    > */
    >
    > +#define DEBUG
    > +
    > #include <linux/init.h>
    > #include <linux/smp.h>
    > #include <linux/module.h>
    > @@ -686,8 +688,8 @@
    > };
    >
    > INIT_WORK(&c_idle.work, do_fork_idle);
    > -
    > - alternatives_smp_switch(1);
    > + if (!is_offsched(cpu))
    > + alternatives_smp_switch(1);
    >
    > c_idle.idle = get_idle_for_cpu(cpu);
    >
    > @@ -1283,8 +1285,9 @@
    > for (i = 0; i < 10; i++) {
    > /* They ack this in play_dead by setting CPU_DEAD */
    > if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
    > - printk(KERN_INFO "CPU %d is now offline\n", cpu);
    > - if (1 == num_online_cpus())
    > + printk(KERN_INFO "CPU %d is now offline %s\n", cpu,
    > + is_offsched(cpu) ? "and OFFSCHED" : "");
    > + if (1 == num_online_cpus() && !is_offsched(cpu))
    > alternatives_smp_switch(0);
    > return;
    > }
    > @@ -1313,6 +1316,8 @@
    > void native_play_dead(void)
    > {
    > play_dead_common();
    > + if (is_offsched(raw_smp_processor_id()))
    > + run_offsched();
    > wbinvd_halt();
    > }
    >
    >
    >
    > --
    > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    > the body of a message to majordomo@vger.kernel.org
    > More majordomo info at http://vger.kernel.org/majordomo-info.html
    > Please read the FAQ at http://www.tux.org/lkml/


    \
     
     \ /
      Last update: 2009-08-26 09:33    [W:2.294 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site