diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-01-18 15:59:45 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-03-24 09:38:51 +0000 |
| commit | 149c24151e8577b2a033639722dc5734de5e6eaf (patch) | |
| tree | 2147e5cde46ab5f57880284b713786db933fe42a | |
| parent | 94e5a85b3be0ce109d26aa6812b2a02c518a0e4b (diff) | |
ARM: SMP: use a timing out completion for cpu hotplug
Rather than open-coding the jiffy-based wait, and polling for the
secondary CPU to come online, use a completion instead. This
removes the need to poll, instead we will be notified when the
secondary CPU has initialized.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/kernel/smp.c | 17 |
1 files changed, 6 insertions, 11 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 57db122a4f6..2b26dca2168 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -58,6 +58,8 @@ enum ipi_msg_type { IPI_CPU_STOP, }; +static DECLARE_COMPLETION(cpu_running); + int __cpuinit __cpu_up(unsigned int cpu) { struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu); @@ -98,20 +100,12 @@ int __cpuinit __cpu_up(unsigned int cpu) */ ret = boot_secondary(cpu, idle); if (ret == 0) { - unsigned long timeout; - /* * CPU was successfully started, wait for it * to come online or time out. */ - timeout = jiffies + HZ; - while (time_before(jiffies, timeout)) { - if (cpu_online(cpu)) - break; - - udelay(10); - barrier(); - } + wait_for_completion_timeout(&cpu_running, + msecs_to_jiffies(1000)); if (!cpu_online(cpu)) { pr_crit("CPU%u: failed to come online\n", cpu); @@ -300,9 +294,10 @@ asmlinkage void __cpuinit secondary_start_kernel(void) /* * OK, now it's safe to let the boot CPU continue. Wait for * the CPU migration code to notice that the CPU is online - * before we continue. + * before we continue - which happens after __cpu_up returns. */ set_cpu_online(cpu, true); + complete(&cpu_running); /* * Setup the percpu timer for this CPU. |