From 9f14d4f1f1045f161fd4db8a8e194b7825c2874a Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Mon, 1 Oct 2018 14:54:59 -0400 Subject: xarray: Add xa_reserve and xa_release This function reserves a slot in the XArray for users which need to acquire multiple locks before storing their entry in the tree and so cannot use a plain xa_store(). Signed-off-by: Matthew Wilcox --- Documentation/core-api/xarray.rst | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation') diff --git a/Documentation/core-api/xarray.rst b/Documentation/core-api/xarray.rst index 4b101b4f3aa1..2b397da84bcd 100644 --- a/Documentation/core-api/xarray.rst +++ b/Documentation/core-api/xarray.rst @@ -293,6 +293,12 @@ to :c:func:`xas_retry`, and retry the operation if it returns ``true``. of this RCU period. You should restart the lookup from the head of the array. + * - Zero + - :c:func:`xa_is_zero` + - Zero entries appear as ``NULL`` through the Normal API, but occupy + an entry in the XArray which can be used to reserve the index for + future use. + Other internal entries may be added in the future. As far as possible, they will be handled by :c:func:`xas_retry`. -- cgit v1.2.3