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From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
To: Linux Media Mailing List <linux-media@vger.kernel.org>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
	Mauro Carvalho Chehab <mchehab@infradead.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Jonathan Corbet <corbet@lwn.net>,
	kvm@vger.kernel.org, linux-doc@vger.kernel.org
Subject: [PATCH v2 05/27] docs: virt: convert halt-polling.txt to ReST format
Date: Thu,  6 Feb 2020 15:50:02 +0100	[thread overview]
Message-ID: <6af4ab0b9c9977b6de9abe0a120ef0904a631a52.1581000481.git.mchehab+huawei@kernel.org> (raw)
In-Reply-To: <cover.1581000481.git.mchehab+huawei@kernel.org>

- Fix document title to match ReST format
- Convert the table to be properly recognized
- Some indentation fixes to match ReST syntax.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 .../{halt-polling.txt => halt-polling.rst}    | 86 ++++++++++---------
 Documentation/virt/kvm/index.rst              |  1 +
 2 files changed, 46 insertions(+), 41 deletions(-)
 rename Documentation/virt/kvm/{halt-polling.txt => halt-polling.rst} (64%)

diff --git a/Documentation/virt/kvm/halt-polling.txt b/Documentation/virt/kvm/halt-polling.rst
similarity index 64%
rename from Documentation/virt/kvm/halt-polling.txt
rename to Documentation/virt/kvm/halt-polling.rst
index 4f791b128dd2..4922e4a15f18 100644
--- a/Documentation/virt/kvm/halt-polling.txt
+++ b/Documentation/virt/kvm/halt-polling.rst
@@ -1,3 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========================
 The KVM halt polling system
 ===========================
 
@@ -68,7 +71,8 @@ steady state polling interval but will only really do a good job for wakeups
 which come at an approximately constant rate, otherwise there will be constant
 adjustment of the polling interval.
 
-[0] total block time: the time between when the halt polling function is
+[0] total block time:
+		      the time between when the halt polling function is
 		      invoked and a wakeup source received (irrespective of
 		      whether the scheduler is invoked within that function).
 
@@ -81,31 +85,32 @@ shrunk. These variables are defined in include/linux/kvm_host.h and as module
 parameters in virt/kvm/kvm_main.c, or arch/powerpc/kvm/book3s_hv.c in the
 powerpc kvm-hv case.
 
-Module Parameter	|   Description		    |	     Default Value
---------------------------------------------------------------------------------
-halt_poll_ns		| The global max polling    | KVM_HALT_POLL_NS_DEFAULT
-			| interval which defines    |
-			| the ceiling value of the  |
-			| polling interval for      | (per arch value)
-			| each vcpu.		    |
---------------------------------------------------------------------------------
-halt_poll_ns_grow	| The value by which the    | 2
-			| halt polling interval is  |
-			| multiplied in the	    |
-			| grow_halt_poll_ns()	    |
-			| function.		    |
---------------------------------------------------------------------------------
-halt_poll_ns_grow_start | The initial value to grow | 10000
-			| to from zero in the	    |
-			| grow_halt_poll_ns()	    |
-			| function.		    |
---------------------------------------------------------------------------------
-halt_poll_ns_shrink	| The value by which the    | 0
-			| halt polling interval is  |
-			| divided in the	    |
-			| shrink_halt_poll_ns()	    |
-			| function.		    |
---------------------------------------------------------------------------------
++-----------------------+---------------------------+-------------------------+
+|Module Parameter	|   Description		    |	     Default Value    |
++-----------------------+---------------------------+-------------------------+
+|halt_poll_ns		| The global max polling    | KVM_HALT_POLL_NS_DEFAULT|
+|			| interval which defines    |			      |
+|			| the ceiling value of the  |			      |
+|			| polling interval for      | (per arch value)	      |
+|			| each vcpu.		    |			      |
++-----------------------+---------------------------+-------------------------+
+|halt_poll_ns_grow	| The value by which the    | 2			      |
+|			| halt polling interval is  |			      |
+|			| multiplied in the	    |			      |
+|			| grow_halt_poll_ns()	    |			      |
+|			| function.		    |			      |
++-----------------------+---------------------------+-------------------------+
+|halt_poll_ns_grow_start| The initial value to grow | 10000		      |
+|			| to from zero in the	    |			      |
+|			| grow_halt_poll_ns()	    |			      |
+|			| function.		    |			      |
++-----------------------+---------------------------+-------------------------+
+|halt_poll_ns_shrink	| The value by which the    | 0			      |
+|			| halt polling interval is  |			      |
+|			| divided in the	    |			      |
+|			| shrink_halt_poll_ns()	    |			      |
+|			| function.		    |			      |
++-----------------------+---------------------------+-------------------------+
 
 These module parameters can be set from the debugfs files in:
 
@@ -117,20 +122,19 @@ Note: that these module parameters are system wide values and are not able to
 Further Notes
 =============
 
-- Care should be taken when setting the halt_poll_ns module 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. This is because even if a guest has
-wakeups during which very little work is done and which are quite far apart, if
-the period is shorter than the global max polling interval (halt_poll_ns) then
-the host will always poll for the entire block time and thus cpu utilisation
-will go to 100%.
+- Care should be taken when setting the halt_poll_ns module 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. This is because even if a guest has wakeups during which very
+  little work is done and which are quite far apart, if the period is shorter than the
+  global max polling interval (halt_poll_ns) then the host will always poll for the
+  entire block time and thus cpu utilisation will go to 100%.
 
-- Halt polling essentially presents a trade off between power usage and latency
-and the module parameters should be used to tune the affinity for this. Idle
-cpu time is essentially converted to host kernel time with the aim of decreasing
-latency when entering the guest.
+- Halt polling essentially presents a trade off between power usage and latency and
+  the module parameters should be used to tune the affinity for this. Idle cpu time is
+  essentially converted to host kernel time with the aim of decreasing latency when
+  entering the guest.
 
-- Halt polling will only be conducted by the host when no other tasks are
-runnable on that cpu, otherwise the polling will cease immediately and
-schedule will be invoked to allow that other task to run. Thus this doesn't
-allow a guest to denial of service the cpu.
+- Halt polling will only be conducted by the host when no other tasks are runnable on
+  that cpu, otherwise the polling will cease immediately and schedule will be invoked to
+  allow that other task to run. Thus this doesn't allow a guest to denial of service the
+  cpu.
diff --git a/Documentation/virt/kvm/index.rst b/Documentation/virt/kvm/index.rst
index 488c6370a447..b39f4894b61d 100644
--- a/Documentation/virt/kvm/index.rst
+++ b/Documentation/virt/kvm/index.rst
@@ -9,6 +9,7 @@ KVM
 
    amd-memory-encryption
    cpuid
+   halt-polling
    vcpu-requests
 
    arm/index
-- 
2.24.1


  parent reply	other threads:[~2020-02-06 14:50 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-06 14:49 [PATCH v2 00/27] docs: virt: manually convert text documents to ReST format Mauro Carvalho Chehab
2020-02-06 14:49 ` [PATCH v2 01/27] docs: kvm: add arm/pvtime.rst to index.rst Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 03/27] docs: virt: user_mode_linux.rst: update compiling instructions Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 04/27] docs: virt: user_mode_linux.rst: fix URL references Mauro Carvalho Chehab
2020-02-06 14:50 ` Mauro Carvalho Chehab [this message]
2020-02-06 15:41   ` [PATCH v2 05/27] docs: virt: convert halt-polling.txt to ReST format Cornelia Huck
2020-02-06 14:50 ` [PATCH v2 06/27] docs: virt: Convert msr.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 07/27] docs: kvm: devices/arm-vgic-its.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 08/27] docs: kvm: devices/arm-vgit-v3.txt to ReST Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 09/27] docs: kvm: convert devices/arm-vgit.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 10/27] docs: kvm: convert devices/mpic.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 11/27] docs: kvm: convert devices/s390_flic.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 12/27] docs: kvm: convert devices/vcpu.txt " Mauro Carvalho Chehab
2020-02-06 15:47   ` Cornelia Huck
2020-02-06 14:50 ` [PATCH v2 13/27] " Mauro Carvalho Chehab
2020-02-06 15:54   ` Cornelia Huck
2020-02-06 14:50 ` [PATCH v2 14/27] docs: kvm: convert devices/vm.txt " Mauro Carvalho Chehab
2020-02-06 15:57   ` Cornelia Huck
2020-02-06 14:50 ` [PATCH v2 15/27] docs: kvm: convert devices/xics.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 16/27] docs: kvm: convert devices/xive.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 18/27] docs: kvm: convert arm/hyp-abi.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 19/27] docs: kvm: arm/psci.txt: convert " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 20/27] docs: kvm: Convert hypercalls.txt to ReST format Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 21/27] docs: kvm: Convert locking.txt " Mauro Carvalho Chehab
2020-02-06 16:11   ` Cornelia Huck
2020-02-06 21:57     ` Paolo Bonzini
2020-02-06 22:47       ` Mauro Carvalho Chehab
2020-02-06 23:13         ` Paolo Bonzini
2020-02-07  6:24         ` Mauro Carvalho Chehab
2020-02-07  8:48           ` Cornelia Huck
2020-02-10  5:58             ` Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 22/27] docs: kvm: Convert mmu.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 23/27] docs: kvm: Convert nested-vmx.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 24/27] docs: kvm: Convert ppc-pv.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 25/27] docs: kvm: Convert s390-diag.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 26/27] docs: kvm: Convert timekeeping.txt " Mauro Carvalho Chehab
2020-02-06 14:50 ` [PATCH v2 27/27] docs: kvm: review-checklist.txt: rename to ReST Mauro Carvalho Chehab
2020-02-06 16:13   ` Cornelia Huck
2020-02-06 15:18 ` [PATCH v2 00/27] docs: virt: manually convert text documents to ReST format Paolo Bonzini
2020-02-06 16:17 ` Cornelia Huck
2020-02-06 16:21   ` Mauro Carvalho Chehab

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