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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2016-12-12 16:46:20 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-12 18:55:09 -0800 |
| commit | a2ef9471c771427c2ddd56677b8de45021f6fd71 (patch) | |
| tree | 708404faa2d25e02dae713f8e60cd7c9430a4f89 /lib/idr.c | |
| parent | ce093a04543c403d52c1a5788d8cb92e47453aba (diff) | |
| download | linux-a2ef9471c771427c2ddd56677b8de45021f6fd71.tar.gz linux-a2ef9471c771427c2ddd56677b8de45021f6fd71.tar.xz | |
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>
Diffstat (limited to 'lib/idr.c')
| -rw-r--r-- | lib/idr.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/lib/idr.c b/lib/idr.c index 6098336df267..52d2979a05e8 100644 --- a/lib/idr.c +++ b/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) { |