diff options
Diffstat (limited to 'drivers/base/cpu.c')
| -rw-r--r-- | drivers/base/cpu.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 43dab03958f1..9ea22e165acd 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -19,6 +19,7 @@ #include <linux/cpufeature.h> #include <linux/tick.h> #include <linux/pm_qos.h> +#include <linux/delay.h> #include <linux/sched/isolation.h> #include "base.h" @@ -50,12 +51,30 @@ static int cpu_subsys_online(struct device *dev) int cpuid = dev->id; int from_nid, to_nid; int ret; + int retries = 0; from_nid = cpu_to_node(cpuid); if (from_nid == NUMA_NO_NODE) return -ENODEV; +retry: ret = cpu_device_up(dev); + + /* + * If -EBUSY is returned, it is likely that hotplug is temporarily + * disabled when cpu_hotplug_disable() was called. This condition is + * transient. So we retry after waiting for an exponentially + * increasing delay up to a total of at least 620ms as some PCI + * device initialization can take quite a while. + */ + if (ret == -EBUSY) { + retries++; + if (retries > 5) + return ret; + msleep(10 * (1 << retries)); + goto retry; + } + /* * When hot adding memory to memoryless node and enabling a cpu * on the node, node number of the cpu may internally change. |