diff options
Diffstat (limited to 'kernel/smpboot.c')
| -rw-r--r-- | kernel/smpboot.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/kernel/smpboot.c b/kernel/smpboot.c index f6bc0bc8a2aa..2c7396da470c 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -392,6 +392,13 @@ int cpu_check_up_prepare(int cpu) */ return -EAGAIN; + case CPU_UP_PREPARE: + /* + * Timeout while waiting for the CPU to show up. Allow to try + * again later. + */ + return 0; + default: /* Should not happen. Famous last words. */ @@ -426,7 +433,7 @@ bool cpu_wait_death(unsigned int cpu, int seconds) /* The outgoing CPU will normally get done quite quickly. */ if (atomic_read(&per_cpu(cpu_hotplug_state, cpu)) == CPU_DEAD) - goto update_state; + goto update_state_early; udelay(5); /* But if the outgoing CPU dawdles, wait increasingly long times. */ @@ -437,16 +444,17 @@ bool cpu_wait_death(unsigned int cpu, int seconds) break; sleep_jf = DIV_ROUND_UP(sleep_jf * 11, 10); } -update_state: +update_state_early: oldstate = atomic_read(&per_cpu(cpu_hotplug_state, cpu)); +update_state: if (oldstate == CPU_DEAD) { /* Outgoing CPU died normally, update state. */ smp_mb(); /* atomic_read() before update. */ atomic_set(&per_cpu(cpu_hotplug_state, cpu), CPU_POST_DEAD); } else { /* Outgoing CPU still hasn't died, set state accordingly. */ - if (atomic_cmpxchg(&per_cpu(cpu_hotplug_state, cpu), - oldstate, CPU_BROKEN) != oldstate) + if (!atomic_try_cmpxchg(&per_cpu(cpu_hotplug_state, cpu), + &oldstate, CPU_BROKEN)) goto update_state; ret = false; } @@ -468,14 +476,14 @@ bool cpu_report_death(void) int newstate; int cpu = smp_processor_id(); + oldstate = atomic_read(&per_cpu(cpu_hotplug_state, cpu)); do { - oldstate = atomic_read(&per_cpu(cpu_hotplug_state, cpu)); if (oldstate != CPU_BROKEN) newstate = CPU_DEAD; else newstate = CPU_DEAD_FROZEN; - } while (atomic_cmpxchg(&per_cpu(cpu_hotplug_state, cpu), - oldstate, newstate) != oldstate); + } while (!atomic_try_cmpxchg(&per_cpu(cpu_hotplug_state, cpu), + &oldstate, newstate)); return newstate == CPU_DEAD; } |