lib/ida: document locking requirements a bit better

I wanted to wrap a bunch of ida_simple_get calls into their own locking,
until I dug around and read the original commit message.  Stuff like
this should imo be added to the kernel doc, let's do that.

Link: http://lkml.kernel.org/r/20161027072216.20411-1-daniel.vetter@ffwll.ch
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Daniel Vetter 2016-12-12 16:46:20 -08:00 committed by Linus Torvalds
parent ce093a0454
commit a2ef9471c7

View File

@ -927,6 +927,9 @@ EXPORT_SYMBOL(ida_pre_get);
* and go back to the ida_pre_get() call. If the ida is full, it will
* return %-ENOSPC.
*
* Note that callers must ensure that concurrent access to @ida is not possible.
* See ida_simple_get() for a varaint which takes care of locking.
*
* @p_id returns a value in the range @starting_id ... %0x7fffffff.
*/
int ida_get_new_above(struct ida *ida, int starting_id, int *p_id)
@ -1073,6 +1076,9 @@ EXPORT_SYMBOL(ida_destroy);
* Allocates an id in the range start <= id < end, or returns -ENOSPC.
* On memory allocation failure, returns -ENOMEM.
*
* Compared to ida_get_new_above() this function does its own locking, and
* should be used unless there are special requirements.
*
* Use ida_simple_remove() to get rid of an id.
*/
int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end,
@ -1119,6 +1125,11 @@ EXPORT_SYMBOL(ida_simple_get);
* ida_simple_remove - remove an allocated id.
* @ida: the (initialized) ida.
* @id: the id returned by ida_simple_get.
*
* Use to release an id allocated with ida_simple_get().
*
* Compared to ida_remove() this function does its own locking, and should be
* used unless there are special requirements.
*/
void ida_simple_remove(struct ida *ida, unsigned int id)
{