[PATCH v3 3/3] Documentation/cgroup-v2: clarify that zswap.writeback is ignored if zswap is disabled

[Mike Yuan]

As discussed in [1], zswap-related settings natually
lose their effect when zswap is disabled, specifically
zswap.writeback here. Be explicit about this behavior.

[1] https://lore.kernel.org/linux-kernel/CAKEwX=Mhbwhh-=xxCU-RjMXS_n=RpV3Gtznb2m_3JgL+jzz++g@xxxxxxxxxxxxxx/

Cc: Nhat Pham <nphamcs@xxxxxxxxx>
Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx>

Signed-off-by: Mike Yuan <me@xxxxxxxxxxx>
---
 Documentation/admin-guide/cgroup-v2.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 95c18bc17083..a1723e402596 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1731,6 +1731,8 @@ The following nested keys are defined.
 
 	Note that this is subtly different from setting memory.swap.max to
 	0, as it still allows for pages to be written to the zswap pool.
+	This setting has no effect if zswap is disabled, and swapping
+	would be allowed unless memory.swap.max is set to 0.
 
   memory.pressure
 	A read-only nested-keyed file.
-- 
2.46.0