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 3c6bf639887ff4686613cae0435fd40d5c9a4f9f..a3c26d587752fe04f34739f266c5f5416d431c9b 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