[patch V2 04/24] padata: Avoid nested calls to get_online_cpus() in pcrypt_init_padata()
flat view
STALE3441d
From: Thomas Gleixner <hidden>
Date: 2017-04-18 19:49:38
Also in:
linux-crypto
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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@linutronix.de>
Signed-off-by: Thomas Gleixner <redacted>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
---
kernel/padata.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/kernel/padata.c
+++ b/kernel/padata.c@@ -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) {