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-rw-r--r--Documentation/virt/guest-halt-polling.rst (renamed from Documentation/virtual/guest-halt-polling.txt)12
-rw-r--r--Documentation/virt/index.rst1
2 files changed, 10 insertions, 3 deletions
diff --git a/Documentation/virtual/guest-halt-polling.txt b/Documentation/virt/guest-halt-polling.rst
index b3a2a294532d..b4e747942417 100644
--- a/Documentation/virtual/guest-halt-polling.txt
+++ b/Documentation/virt/guest-halt-polling.rst
@@ -1,9 +1,11 @@
+==================
Guest halt polling
==================
The cpuidle_haltpoll driver, with the haltpoll governor, allows
the guest vcpus to poll for a specified amount of time before
halting.
+
This provides the following benefits to host side polling:
1) The POLL flag is set while polling is performed, which allows
@@ -29,18 +31,21 @@ Module Parameters
The haltpoll governor has 5 tunable module parameters:
1) guest_halt_poll_ns:
+
Maximum amount of time, in nanoseconds, that polling is
performed before halting.
Default: 200000
2) guest_halt_poll_shrink:
+
Division factor used to shrink per-cpu guest_halt_poll_ns when
wakeup event occurs after the global guest_halt_poll_ns.
Default: 2
3) guest_halt_poll_grow:
+
Multiplication factor used to grow per-cpu guest_halt_poll_ns
when event occurs after per-cpu guest_halt_poll_ns
but before global guest_halt_poll_ns.
@@ -48,6 +53,7 @@ but before global guest_halt_poll_ns.
Default: 2
4) guest_halt_poll_grow_start:
+
The per-cpu guest_halt_poll_ns eventually reaches zero
in case of an idle system. This value sets the initial
per-cpu guest_halt_poll_ns when growing. This can
@@ -66,7 +72,7 @@ high once achieves global guest_halt_poll_ns value).
Default: Y
-The module parameters can be set from the debugfs files in:
+The module parameters can be set from the debugfs files in::
/sys/module/haltpoll/parameters/
@@ -74,5 +80,5 @@ Further Notes
=============
- Care should be taken when setting the guest_halt_poll_ns parameter as a
-large value has the potential to drive the cpu usage to 100% on a machine which
-would be almost entirely idle otherwise.
+ large value has the potential to drive the cpu usage to 100% on a machine
+ which would be almost entirely idle otherwise.
diff --git a/Documentation/virt/index.rst b/Documentation/virt/index.rst
index 0a8f7fda64ad..de1ab81df958 100644
--- a/Documentation/virt/index.rst
+++ b/Documentation/virt/index.rst
@@ -10,6 +10,7 @@ Linux Virtualization Support
kvm/index
uml/user_mode_linux
paravirt_ops
+ guest-halt-polling
.. only:: html and subproject