docs: Update memory pressure docs for latest GLib support for it

As of GLib 2.90.0 (not yet released), GLib will fully support the spec,
including the `MEMORY_PRESSURE_WATCH` and `MEMORY_PRESSURE_WRITE`
environment variables, which it did not support previously.

See https://gitlab.gnome.org/GNOME/glib/-/merge_requests/5046

diff --git a/docs/PRESSURE.md b/docs/PRESSURE.md
index 29efc07e5cf1375df4238d38c0b0b121854e708b..2dcc0be7215506f33d2f41dec5c404ad266dbcae 100644 (file)
--- a/docs/PRESSURE.md
+++ b/docs/PRESSURE.md
@@ -241,9 +241,12 @@ a custom handler should be provided to take appropriate action:
 
 Other programming environments might have native APIs to watch memory
 pressure/low memory events. Most notable is probably GLib's
-[GMemoryMonitor](https://docs.gtk.org/gio/iface.MemoryMonitor.html). As of GLib
-2.86.0, it uses the per-cgroup PSI kernel file to monitor for memory pressure,
-but does not yet read the environment variables recommended above.
+[GMemoryMonitor](https://docs.gtk.org/gio/iface.MemoryMonitor.html). Versions
+2.90.0 and later of GLib fully support this per-cgroup PSI kernel file protocol.
+
+Versions of GLib between 2.86.0 and 2.90.0 used the per-cgroup PSI kernel file
+to monitor for memory pressure, but did not read the environment variables
+recommended above.
 
 In older versions, it used the per-system Linux PSI interface as the backend, but operated
 differently than the above: memory pressure events were picked up by a system