[PATCH] padata: add helper function for queue length
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: 2016-10-02 01:47:05
Also in:
lkml
Subsystem:
padata parallel execution mechanism, the rest · Maintainers:
Steffen Klassert, Daniel Jordan, Linus Torvalds
Since padata has a maximum number of inflight jobs, currently 1000, it's very useful to know how many jobs are currently queued up. This adds a simple helper function to expose this information. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> --- include/linux/padata.h | 2 ++ kernel/padata.c | 16 ++++++++++++++++ 2 files changed, 18 insertions(+)
diff --git a/include/linux/padata.h b/include/linux/padata.h
index 113ee62..4840ae4 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h@@ -3,6 +3,7 @@ * * Copyright (C) 2008, 2009 secunet Security Networks AG * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com> + * Copyright (C) 2016 Jason A. Donenfeld <Jason@zx2c4.com> * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License,
@@ -181,4 +182,5 @@ extern int padata_register_cpumask_notifier(struct padata_instance *pinst, struct notifier_block *nblock); extern int padata_unregister_cpumask_notifier(struct padata_instance *pinst, struct notifier_block *nblock); +extern int padata_queue_len(struct padata_instance *pinst); #endif
diff --git a/kernel/padata.c b/kernel/padata.c
index 9932788..17c1e08 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c@@ -5,6 +5,7 @@ * * Copyright (C) 2008, 2009 secunet Security Networks AG * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com> + * Copyright (C) 2016 Jason A. Donenfeld <Jason@zx2c4.com> * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License,
@@ -1039,3 +1040,18 @@ void padata_free(struct padata_instance *pinst) kobject_put(&pinst->kobj); } EXPORT_SYMBOL(padata_free); + +/** + * padata_queue_len - retreive the number of in progress jobs + * + * @padata_inst: padata instance from which to read the queue size + */ +int padata_queue_len(struct padata_instance *pinst) +{ + int len; + rcu_read_lock_bh(); + len = atomic_read(&rcu_dereference_bh(pinst->pd)->refcnt); + rcu_read_unlock_bh(); + return len; +} +EXPORT_SYMBOL(padata_queue_len);
--
2.10.0