From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
pcrypt_init_padata()
get_online_cpus()
padata_alloc_possible()
padata_alloc()
get_online_cpus()
The nested call to get_online_cpus() works with the current implementation,
but prevents the conversion to a percpu rwsem.
The other caller of padata_alloc_possible() is pcrypt_init_padata() which
calls from a get_online_cpus() protected region as well.
Remove the get_online_cpus() call in padata_alloc() and document the
calling convention.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Cc: linux-crypto@xxxxxxxxxxxxxxx
---
kernel/padata.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -913,7 +913,7 @@ static ssize_t padata_sysfs_show(struct
}
static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr,
-s const char *buf, size_t count)
+ const char *buf, size_t count)
{
struct padata_instance *pinst;
struct padata_sysfs_entry *pentry;
@@ -945,6 +945,8 @@ static struct kobj_type padata_attr_type
* @wq: workqueue to use for the allocated padata instance
* @pcpumask: cpumask that will be used for padata parallelization
* @cbcpumask: cpumask that will be used for padata serialization
+ *
+ * Must be called from a get_online_cpus() protected region
*/
static struct padata_instance *padata_alloc(struct workqueue_struct *wq,
const struct cpumask *pcpumask,
@@ -957,7 +959,6 @@ static struct padata_instance *padata_al
if (!pinst)
goto err;
- get_online_cpus();
if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL))
goto err_free_inst;
if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) {
@@ -997,7 +998,6 @@ static struct padata_instance *padata_al
free_cpumask_var(pinst->cpumask.cbcpu);
err_free_inst:
kfree(pinst);
- put_online_cpus();
err:
return NULL;
}
@@ -1008,6 +1008,8 @@ static struct padata_instance *padata_al
* parallel workers.
*
* @wq: workqueue to use for the allocated padata instance
+ *
+ * Must be called from a get_online_cpus() protected region
*/
struct padata_instance *padata_alloc_possible(struct workqueue_struct *wq)
{
