From: Daniel Vetter <daniel.vetter@xxxxxxxx> Subject: 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@xxxxxxxx Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> Acked-by: Tejun Heo <tj@xxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/idr.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff -puN lib/idr.c~lib-ida-document-locking-requirements-a-bit-better-v2 lib/idr.c --- a/lib/idr.c~lib-ida-document-locking-requirements-a-bit-better-v2 +++ a/lib/idr.c @@ -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) { _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
