[patch 05/11] appldata: prevent cpu hotplug when walking cpu_online_map.

Martin Schwidefsky
2008-05-29T13:03:22Z

[-- Attachment #1: 005-appldate-getcpu.diff --]
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From: Gerald Schaefer <gerald.schaefer@de.ibm.com>

Use get_online_cpus() to prevent cpu hotplug in situations where
for_each_online_cpu() is called.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

arch/s390/appldata/appldata_base.c | 8 ++++++++
1 file changed, 8 insertions(+)

Index: quilt-2.6/arch/s390/appldata/appldata_base.c
===================================================================
--- quilt-2.6.orig/arch/s390/appldata/appldata_base.c
+++ quilt-2.6/arch/s390/appldata/appldata_base.c
@@ -130,6 +130,7 @@ static void appldata_work_fn(struct work

P_DEBUG(" -= Work Queue =-\n");
i = 0;
+ get_online_cpus();
spin_lock(&appldata_ops_lock);
list_for_each(lh, &appldata_ops_list) {
ops = list_entry(lh, struct appldata_ops, list);
@@ -140,6 +141,7 @@ static void appldata_work_fn(struct work
}
}
spin_unlock(&appldata_ops_lock);
+ put_online_cpus();
}

/*
@@ -266,12 +268,14 @@ appldata_timer_handler(ctl_table *ctl, i
len = *lenp;
if (copy_from_user(buf, buffer, len > sizeof(buf) ? sizeof(buf) : len))
return -EFAULT;
+ get_online_cpus();
spin_lock(&appldata_timer_lock);
if (buf[0] == '1')
__appldata_vtimer_setup(APPLDATA_ADD_TIMER);
else if (buf[0] == '0')
__appldata_vtimer_setup(APPLDATA_DEL_TIMER);
spin_unlock(&appldata_timer_lock);
+ put_online_cpus();
out:
*lenp = len;
*ppos += len;
@@ -314,10 +318,12 @@ appldata_interval_handler(ctl_table *ctl
return -EINVAL;
}

+ get_online_cpus();
spin_lock(&appldata_timer_lock);
appldata_interval = interval;
__appldata_vtimer_setup(APPLDATA_MOD_TIMER);
spin_unlock(&appldata_timer_lock);
+ put_online_cpus();

P_INFO("Monitoring CPU interval set to %u milliseconds.\n",
interval);
@@ -556,8 +562,10 @@ static int __init appldata_init(void)
return -ENOMEM;
}

+ get_online_cpus();
for_each_online_cpu(i)
appldata_online_cpu(i);
+ put_online_cpus();

/* Register cpu hotplug notifier */
register_hotcpu_notifier(&appldata_nb);