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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-01-18 15:59:45 +0000 |
|---|---|---|
| committer | Andrew Dodd <atd7@cornell.edu> | 2012-11-13 19:15:50 -0500 |
| commit | 5ddd587f9564e31f0767b3f352aadbba5ab69e9e (patch) | |
| tree | 77b3edc3d8cc1339283ee44cf94f5532305c245b /arch/arm/kernel | |
| parent | 3c3b858c0168ae826525595ef2fb5d275484f989 (diff) | |
| download | kernel_samsung_smdk4412-5ddd587f9564e31f0767b3f352aadbba5ab69e9e.tar.gz kernel_samsung_smdk4412-5ddd587f9564e31f0767b3f352aadbba5ab69e9e.tar.bz2 kernel_samsung_smdk4412-5ddd587f9564e31f0767b3f352aadbba5ab69e9e.zip | |
ARM: SMP: use a timing out completion for cpu hotplug
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 ffc8fb6cb4c..e550be97ebf 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -58,6 +58,8 @@ enum ipi_msg_type { IPI_CPU_BACKTRACE, }; +static DECLARE_COMPLETION(cpu_running); + int __cpuinit __cpu_up(unsigned int cpu) { struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu); @@ -117,20 +119,12 @@ 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); @@ -328,9 +322,10 @@ 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. |