documentation: Update NO_HZ_FULL interaction with POSIX timers

POSIX timers are no longer starved on adaptive-ticks CPUs.  Instead, they
prevent affected CPUs from entering adaptive-ticks mode.  This commit
therefore updates the NO_HZ.txt documentation.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/Documentation/timers/NO_HZ.txt b/Documentation/timers/NO_HZ.txt
index cca122f..6eaf576 100644 (file)
--- a/Documentation/timers/NO_HZ.txt
+++ b/Documentation/timers/NO_HZ.txt
@@ -158,13 +158,9 @@ not come for free:
        to the need to inform kernel subsystems (such as RCU) about
        the change in mode.
 
-3.     POSIX CPU timers on adaptive-tick CPUs may miss their deadlines
-       (perhaps indefinitely) because they currently rely on
-       scheduling-tick interrupts.  This will likely be fixed in
-       one of two ways: (1) Prevent CPUs with POSIX CPU timers from
-       entering adaptive-tick mode, or (2) Use hrtimers or other
-       adaptive-ticks-immune mechanism to cause the POSIX CPU timer to
-       fire properly.
+3.     POSIX CPU timers prevent CPUs from entering adaptive-tick mode.
+       Real-time applications needing to take actions based on CPU time
+       consumption need to use other means of doing so.
 
 4.     If there are more perf events pending than the hardware can
        accommodate, they are normally round-robined so as to collect