tick/nohz: Update nohz_full Kconfig help

CONFIG_NO_HZ_FULL behaves just like CONFIG_NO_HZ_IDLE by default.
Reassure distros about it.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512232924.150322-6-frederic@kernel.org

diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 83e158d..7df71ef 100644 (file)
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -117,13 +117,14 @@ config NO_HZ_FULL
         the task mostly runs in userspace and has few kernel activity.
 
         You need to fill up the nohz_full boot parameter with the
-        desired range of dynticks CPUs.
+        desired range of dynticks CPUs to use it. This is implemented at
+        the expense of some overhead in user <-> kernel transitions:
+        syscalls, exceptions and interrupts.
 
-        This is implemented at the expense of some overhead in user <-> kernel
-        transitions: syscalls, exceptions and interrupts. Even when it's
-        dynamically off.
+        By default, without passing the nohz_full parameter, this behaves just
+        like NO_HZ_IDLE.
 
-        Say N.
+        If you're a distro say Y.
 
 endchoice