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author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-24 04:36:53 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-24 04:36:53 +0200 |
commit | 7f9dce38378f0a4a298e885553d6bb7121376376 (patch) | |
tree | 5bfd688c9f356f7216bbc3cef3b4c10153de334b /kernel/cpu.c | |
parent | Merge branch 'cpus4096-for-linus' of git://git.kernel.org/pub/scm/linux/kerne... (diff) | |
parent | sched: hrtick_enabled() should use cpu_active() (diff) | |
download | linux-7f9dce38378f0a4a298e885553d6bb7121376376.tar.xz linux-7f9dce38378f0a4a298e885553d6bb7121376376.zip |
Merge branch 'sched/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: hrtick_enabled() should use cpu_active()
sched, x86: clean up hrtick implementation
sched: fix build error, provide partition_sched_domains() unconditionally
sched: fix warning in inc_rt_tasks() to not declare variable 'rq' if it's not needed
cpu hotplug: Make cpu_active_map synchronization dependency clear
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2)
sched: rework of "prioritize non-migratable tasks over migratable ones"
sched: reduce stack size in isolated_cpu_setup()
Revert parts of "ftrace: do not trace scheduler functions"
Fixed up conflicts in include/asm-x86/thread_info.h (due to the
TIF_SINGLESTEP unification vs TIF_HRTICK_RESCHED removal) and
kernel/sched_fair.c (due to cpu_active_map vs for_each_cpu_mask_nr()
introduction).
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r-- | kernel/cpu.c | 40 |
1 files changed, 34 insertions, 6 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index d26d0b095b3b..2cc409ce0a8f 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -64,6 +64,8 @@ void __init cpu_hotplug_init(void) cpu_hotplug.refcount = 0; } +cpumask_t cpu_active_map; + #ifdef CONFIG_HOTPLUG_CPU void get_online_cpus(void) @@ -291,11 +293,30 @@ int __ref cpu_down(unsigned int cpu) int err = 0; cpu_maps_update_begin(); - if (cpu_hotplug_disabled) + + if (cpu_hotplug_disabled) { err = -EBUSY; - else - err = _cpu_down(cpu, 0); + goto out; + } + + cpu_clear(cpu, cpu_active_map); + + /* + * Make sure the all cpus did the reschedule and are not + * using stale version of the cpu_active_map. + * This is not strictly necessary becuase stop_machine() + * that we run down the line already provides the required + * synchronization. But it's really a side effect and we do not + * want to depend on the innards of the stop_machine here. + */ + synchronize_sched(); + + err = _cpu_down(cpu, 0); + if (cpu_online(cpu)) + cpu_set(cpu, cpu_active_map); + +out: cpu_maps_update_done(); return err; } @@ -355,11 +376,18 @@ int __cpuinit cpu_up(unsigned int cpu) } cpu_maps_update_begin(); - if (cpu_hotplug_disabled) + + if (cpu_hotplug_disabled) { err = -EBUSY; - else - err = _cpu_up(cpu, 0); + goto out; + } + + err = _cpu_up(cpu, 0); + if (cpu_online(cpu)) + cpu_set(cpu, cpu_active_map); + +out: cpu_maps_update_done(); return err; } |