zsmalloc: document freeable stats

When freeable class stat was added to classes file (back in 2016) we
forgot to update zsmalloc documentation.  Fix that.

Link: https://lkml.kernel.org/r/20230325024631.2817153-3-senozhatsky@chromium.org
Fixes: 1120ed548394 ("mm/zsmalloc: add `freeable' column to pool stat")
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/Documentation/mm/zsmalloc.rst b/Documentation/mm/zsmalloc.rst
index 3c6bf63..a3c26d5 100644 (file)
--- a/Documentation/mm/zsmalloc.rst
+++ b/Documentation/mm/zsmalloc.rst
@@ -83,6 +83,8 @@ pages_used
        the number of pages allocated for the class
 pages_per_zspage
        the number of 0-order pages to make a zspage
+freeable
+       the approximate number of pages class compaction can free
 
 Each zspage maintains inuse counter which keeps track of the number of
 objects stored in the zspage.  The inuse counter determines the zspage's