lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus()

Browse Source 
Replace all lock_cpu_hotplug/unlock_cpu_hotplug from the kernel and use
get_online_cpus and put_online_cpus instead as it highlights the
refcount semantics in these operations.

The new API guarantees protection against the cpu-hotplug operation, but
it doesn't guarantee serialized access to any of the local data
structures. Hence the changes needs to be reviewed.

In case of pseries_add_processor/pseries_remove_processor, use
cpu_maps_update_begin()/cpu_maps_update_done() as we're modifying the
cpu_present_map there.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Gautham R Shenoy
2008-01-25 21:08:02 +01:00
committed by Ingo Molnar
parent d221938c04
commit 86ef5c9a8e
15 changed files with 62 additions and 61 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
kernel/rcutorture.c
View File

@@ -726,11 +726,11 @@ static void rcu_torture_shuffle_tasks(void)
cpumask_t tmp_mask = CPU_MASK_ALL;
int i;
lock_cpu_hotplug();
get_online_cpus();
/* No point in shuffling if there is only one online CPU (ex: UP) */
if (num_online_cpus() == 1) {
unlock_cpu_hotplug();
put_online_cpus();
return;
}
@@ -762,7 +762,7 @@ static void rcu_torture_shuffle_tasks(void)
else
rcu_idle_cpu--;
unlock_cpu_hotplug();
put_online_cpus();
}
/* Shuffle tasks across CPUs, with the intent of allowing each CPU in the