diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-01-18 15:59:45 +0000 |
|---|---|---|
| committer | Jason Liu <r64343@freescale.com> | 2012-07-20 13:37:59 +0800 |
| commit | 2eb581e5fb93ba6bcac064fd4f447159094da9e5 (patch) | |
| tree | c57674859c7d65267b1cebdef71b4c17855a96c3 /arch/arm/kernel | |
| parent | 956af4c27bb65489696a850e8ff541de24c58fcd (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>
Diffstat (limited to 'arch/arm/kernel')
| -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 69ee510f1541..32ce3530bcc6 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -55,6 +55,8 @@ 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); @@ -114,20 +116,12 @@ 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); @@ -310,9 +304,10 @@ 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. |