Commit e3d074b5 authored by Harald Freudenberger's avatar Harald Freudenberger Committed by Vasily Gorbik
Browse files

s390/pkey: Add comment about synchronize_rcu() to pkey base 

Add a comment about the use of the synchronize_rcu() invocation.
There are two invocations of the synchronize_rcu() call in the
pkey base code. On one place it is optional but used to enforce
a fast path update to the other CPUs. As some people and code
checkers complain about this redundant invocation the suggestion
came up to add a comment to explain why the call is meaningful
at that place.

Closes: https://lore.kernel.org/linux-s390/20260313052312.2389-1-lirongqing@baidu.com/


Suggested-by: default avatarLi Rongqing <lirongqing@baidu.com>
Signed-off-by: default avatarHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: default avatarHolger Dengler <dengler@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 052abf9a

drivers/s390/crypto/pkey_base.c

+7 −0
Original line number Diff line number Diff line
@@ -60,6 +60,13 @@ int pkey_handler_register(struct pkey_handler *handler) 


	list_add_rcu(&handler->list, &handler_list);

	spin_unlock(&handler_list_write_lock);

	/*

	 * Fast path to push the info about the updated list to the other

	 * CPUs. If removed, the other CPUs may get the updated list when the

	 * RCU context is synched. As this code is in general not performance

	 * critical and the list update mostly only occurs at the early time in

	 * system startup the focus is on concurrency versus performance.

	 */

	synchronize_rcu();



	module_put(handler->module);