README: fix context for CONFIG_DEVPTS_MULTIPLE_INSTANCES

`newinstance` (and `ptmxmode`) options of devpts are _not_ used by
PrivateDevices=.  (/dev/pts is shared, similar to how /dev/shm and
/dev/mqueue are handled).  It is used by nspawn containers though.

Also CONFIG_DEVPTS_MULTIPLE_INSTANCES was removed in 4.7-rc2
https://github.com/torvalds/linux/commit/eedf265aa003b4781de24cfed40a655a664457e6
and no longer needs to be set, so make that clearer to avoid confusion.

diff --git a/README b/README
index e54c5d6..8807e5c 100644 (file)
--- a/README
+++ b/README
@@ -69,11 +69,10 @@ REQUIREMENTS:
         create additional symlinks in /dev/disk/ and /dev/tape:
           CONFIG_BLK_DEV_BSG
 
-        Required for PrivateNetwork= and PrivateDevices= in service units:
+        Required for PrivateNetwork= in service units:
           CONFIG_NET_NS
-          CONFIG_DEVPTS_MULTIPLE_INSTANCES
         Note that systemd-localed.service and other systemd units use
-        PrivateNetwork and PrivateDevices so this is effectively required.
+        PrivateNetwork so this is effectively required.
 
         Required for PrivateUsers= in service units:
           CONFIG_USER_NS
@@ -119,6 +118,9 @@ REQUIREMENTS:
         isn't. The next best thing is to make this change through a modprobe.d
         drop-in. This is shipped by default, see modprobe.d/systemd.conf.
 
+        Required for systemd-nspawn:
+          CONFIG_DEVPTS_MULTIPLE_INSTANCES or Linux kernel >= 4.7
+
         Note that kernel auditing is broken when used with systemd's
         container code. When using systemd in conjunction with
         containers, please make sure to either turn off auditing at