Remove nonsensical list function list_for_each_safe_rcu
Subsystems (2)
PATCH 1/1 Remove nonsensical list function list_for_each_safe_rcu
Name: Remove nonsensical list function
Status: Trivial
Signed-off-by Rusty Russell <[email protected]>
The correct use of list_for_each_safe_rcu is a coding puzzle which minor minds such mine are not capable of solving. Please remove this obstacle on my path to enlightenment.
Documentation/RCU/checklist.txt +5 -5
@@ -132,11 +132,11 @@ 9. All RCU list-traversal primitives, which include list_for_each_rcu(), list_for_each_entry_rcu(), - list_for_each_continue_rcu(), and list_for_each_safe_rcu(), - must be within an RCU read-side critical section. RCU - read-side critical sections are delimited by rcu_read_lock() - and rcu_read_unlock(), or by similar primitives such as - rcu_read_lock_bh() and rcu_read_unlock_bh(). + and list_for_each_continue_rcu(), must be within an RCU + read-side critical section. RCU read-side critical sections + are delimited by rcu_read_lock() and rcu_read_unlock(), or by + similar primitives such as rcu_read_lock_bh() + and rcu_read_unlock_bh(). Use of the _rcu() list-traversal primitives outside of an RCU read-side critical section causes no harm other than
include/linux/list.h +0 -15
@@ -436,21 +436,6 @@ pos = rcu_dereference(pos->next))/** -* list_for_each_safe_rcu - iterate over an rcu-protected list safe -* against removal of list entry -* @pos: the &struct list_head to use as a loop counter. -* @n: another &struct list_head to use as temporary storage -* @head: the head for your list. -* -* This list-traversal primitive may safely run concurrently with -* the _rcu list-mutation primitives such as list_add_rcu() -* as long as the traversal is guarded by rcu_read_lock(). -*/ -#define list_for_each_safe_rcu (pos, n, head) \ - for (pos = (head)->next, n = pos->next; pos != (head); \ - pos = rcu_dereference(n), n = pos->next) - -/** * list_for_each_entry_rcu - iterate over rcu list of given type * @pos: the type * to use as a loop counter. * @head: the head for your list.
Signature · 1 line
A bad analogy is like a leaky screwdriver -- Richard Braakman