Commit-ID: bbd8797975ce0191ac72d575f7e34033b5a5f620 Gitweb: http://git.kernel.org/tip/bbd8797975ce0191ac72d575f7e34033b5a5f620 Author: Sebastian Andrzej Siewior <bige...@linutronix.de> AuthorDate: Tue, 18 Apr 2017 19:04:46 +0200 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Thu, 20 Apr 2017 13:08:51 +0200
padata: Avoid nested calls to get_online_cpus() in pcrypt_init_padata() 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 <bige...@linutronix.de> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Cc: Steffen Klassert <steffen.klass...@secunet.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Steven Rostedt <rost...@goodmis.org> Cc: linux-cry...@vger.kernel.org Link: http://lkml.kernel.org/r/20170418170552.697398...@linutronix.de --- kernel/padata.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/padata.c b/kernel/padata.c index 18992bf..e5ff511 100644 --- 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_alloc(struct workqueue_struct *wq, 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 @@ err_free_masks: free_cpumask_var(pinst->cpumask.cbcpu); err_free_inst: kfree(pinst); - put_online_cpus(); err: return NULL; } @@ -1008,6 +1008,8 @@ err: * 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) {