doc: reword "shared per-thread" wording

[elogind.git] / man / systemd-halt.service.xml

diff --git a/man/systemd-halt.service.xml b/man/systemd-halt.service.xml
index 2fd7b8bf80d5481087c01dd1db77efbf5259fe21..552dbdf687a38ab001e8a425f9a5b39f42c5a8c9 100644 (file)
--- a/man/systemd-halt.service.xml
+++ b/man/systemd-halt.service.xml
@@ -65,7 +65,7 @@
                 <para><filename>systemd-halt.service</filename> is a
                 system service that is pulled in by
                 <filename>halt.target</filename> and is responsible
-                for the actual system halt. Similar,
+                for the actual system halt. Similarly,
                 <filename>systemd-poweroff.service</filename> is
                 pulled in by <filename>poweroff.target</filename>,
                 <filename>systemd-reboot.service</filename> by
@@ -83,6 +83,12 @@
                 remaining swap devices, detach all remaining storage
                 devices and kill all remaining processes.</para>
 
+                <para>It is necessary to have this code in a separate binary
+                because otherwise rebooting after an upgrade might be broken —
+                the running PID 1 could still depend on libraries which are not
+                available any more, thus keeping the file system busy, which
+                then cannot be re-mounted read-only.</para>
+
                 <para>Immediately before executing the actual system
                 halt/poweroff/reboot/kexec
                 <filename>systemd-shutdown</filename> will run all