Message-Id: <cb53bf2e4b00c9ba398e17079b3fb4f86d081a47.1555382110.git.mchehab+samsung@kernel.org>
Date:   Mon, 15 Apr 2019 23:56:00 -0300
From:   Mauro Carvalho Chehab <mchehab+samsung@...nel.org>
To:     Linux Doc Mailing List <linux-doc@...r.kernel.org>
Cc:     Mauro Carvalho Chehab <mchehab+samsung@...nel.org>,
        Mauro Carvalho Chehab <mchehab@...radead.org>,
        linux-kernel@...r.kernel.org, Jonathan Corbet <corbet@....net>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 35/57] docs: timers: convert documentation to ReST

The conversion here is really trivial: just a bunch of title
markups and very few puntual changes is enough to make it to
be parsed by Sphinx and generate a nice html.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@...nel.org>
---
 Documentation/timers/NO_HZ.txt        | 40 ++++++++++++++++-----------
 Documentation/timers/highres.txt      | 11 ++++----
 Documentation/timers/hpet.txt         |  4 ++-
 Documentation/timers/hrtimers.txt     |  6 ++--
 Documentation/timers/timekeeping.txt  |  3 +-
 Documentation/timers/timers-howto.txt | 15 +++++++---
 6 files changed, 49 insertions(+), 30 deletions(-)

diff --git a/Documentation/timers/NO_HZ.txt b/Documentation/timers/NO_HZ.txt
index 9591092da5e0..065db217cb04 100644
--- a/Documentation/timers/NO_HZ.txt
+++ b/Documentation/timers/NO_HZ.txt
@@ -1,4 +1,6 @@
-		NO_HZ: Reducing Scheduling-Clock Ticks
+======================================
+NO_HZ: Reducing Scheduling-Clock Ticks
+======================================
 
 
 This document describes Kconfig options and boot parameters that can
@@ -28,7 +30,8 @@ by a third section on RCU-specific considerations, a fourth section
 discussing testing, and a fifth and final section listing known issues.
 
 
-NEVER OMIT SCHEDULING-CLOCK TICKS
+Never Omit Scheduling-Clock Ticks
+=================================
 
 Very old versions of Linux from the 1990s and the very early 2000s
 are incapable of omitting scheduling-clock ticks.  It turns out that
@@ -59,7 +62,8 @@ degrade your applications performance.  If this describes your workload,
 you should read the following two sections.
 
 
-OMIT SCHEDULING-CLOCK TICKS FOR IDLE CPUs
+Omit Scheduling-Clock Ticks For Idle CPUs
+=========================================
 
 If a CPU is idle, there is little point in sending it a scheduling-clock
 interrupt.  After all, the primary purpose of a scheduling-clock interrupt
@@ -97,7 +101,8 @@ By default, CONFIG_NO_HZ_IDLE=y kernels boot with "nohz=on", enabling
 dyntick-idle mode.
 
 
-OMIT SCHEDULING-CLOCK TICKS FOR CPUs WITH ONLY ONE RUNNABLE TASK
+Omit Scheduling-Clock Ticks For CPUs With Only One Runnable Task
+================================================================
 
 If a CPU has only one runnable task, there is little point in sending it
 a scheduling-clock interrupt because there is no other task to switch to.
@@ -174,7 +179,8 @@ However, the drawbacks listed above mean that adaptive ticks should not
 (yet) be enabled by default.
 
 
-RCU IMPLICATIONS
+RCU Implications
+================
 
 There are situations in which idle CPUs cannot be permitted to
 enter either dyntick-idle mode or adaptive-tick mode, the most
@@ -199,7 +205,8 @@ scheduler will decide where to run them, which might or might not be
 where you want them to run.
 
 
-TESTING
+Testing
+=======
 
 So you enable all the OS-jitter features described in this document,
 but do not see any change in your workload's behavior.  Is this because
@@ -222,9 +229,10 @@ We do not currently have a good way to remove OS jitter from single-CPU
 systems.
 
 
-KNOWN ISSUES
+Known Issues
+============
 
-o	Dyntick-idle slows transitions to and from idle slightly.
+*	Dyntick-idle slows transitions to and from idle slightly.
 	In practice, this has not been a problem except for the most
 	aggressive real-time workloads, which have the option of disabling
 	dyntick-idle mode, an option that most of them take.  However,
@@ -248,13 +256,13 @@ o	Dyntick-idle slows transitions to and from idle slightly.
 		this parameter effectively disables Turbo Mode on Intel
 		CPUs, which can significantly reduce maximum performance.
 
-o	Adaptive-ticks slows user/kernel transitions slightly.
+*	Adaptive-ticks slows user/kernel transitions slightly.
 	This is not expected to be a problem for computationally intensive
 	workloads, which have few such transitions.  Careful benchmarking
 	will be required to determine whether or not other workloads
 	are significantly affected by this effect.
 
-o	Adaptive-ticks does not do anything unless there is only one
+*	Adaptive-ticks does not do anything unless there is only one
 	runnable task for a given CPU, even though there are a number
 	of other situations where the scheduling-clock tick is not
 	needed.  To give but one example, consider a CPU that has one
@@ -275,7 +283,7 @@ o	Adaptive-ticks does not do anything unless there is only one
 
 	Better handling of these sorts of situations is future work.
 
-o	A reboot is required to reconfigure both adaptive idle and RCU
+*	A reboot is required to reconfigure both adaptive idle and RCU
 	callback offloading.  Runtime reconfiguration could be provided
 	if needed, however, due to the complexity of reconfiguring RCU at
 	runtime, there would need to be an earthshakingly good reason.
@@ -283,12 +291,12 @@ o	A reboot is required to reconfigure both adaptive idle and RCU
 	simply offloading RCU callbacks from all CPUs and pinning them
 	where you want them whenever you want them pinned.
 
-o	Additional configuration is required to deal with other sources
+*	Additional configuration is required to deal with other sources
 	of OS jitter, including interrupts and system-utility tasks
 	and processes.  This configuration normally involves binding
 	interrupts and tasks to particular CPUs.
 
-o	Some sources of OS jitter can currently be eliminated only by
+*	Some sources of OS jitter can currently be eliminated only by
 	constraining the workload.  For example, the only way to eliminate
 	OS jitter due to global TLB shootdowns is to avoid the unmapping
 	operations (such as kernel module unload operations) that
@@ -299,17 +307,17 @@ o	Some sources of OS jitter can currently be eliminated only by
 	helpful, especially when combined with the mlock() and mlockall()
 	system calls.
 
-o	Unless all CPUs are idle, at least one CPU must keep the
+*	Unless all CPUs are idle, at least one CPU must keep the
 	scheduling-clock interrupt going in order to support accurate
 	timekeeping.
 
-o	If there might potentially be some adaptive-ticks CPUs, there
+*	If there might potentially be some adaptive-ticks CPUs, there
 	will be at least one CPU keeping the scheduling-clock interrupt
 	going, even if all CPUs are otherwise idle.
 
 	Better handling of this situation is ongoing work.
 
-o	Some process-handling operations still require the occasional
+*	Some process-handling operations still require the occasional
 	scheduling-clock tick.	These operations include calculating CPU
 	load, maintaining sched average, computing CFS entity vruntime,
 	computing avenrun, and carrying out load balancing.  They are
diff --git a/Documentation/timers/highres.txt b/Documentation/timers/highres.txt
index 8f9741592123..f93528e6f1c8 100644
--- a/Documentation/timers/highres.txt
+++ b/Documentation/timers/highres.txt
@@ -1,5 +1,6 @@
+=====================================================
 High resolution timers and dynamic ticks design notes
------------------------------------------------------
+=====================================================
 
 Further information can be found in the paper of the OLS 2006 talk "hrtimers
 and beyond". The paper is part of the OLS 2006 Proceedings Volume 1, which can
@@ -35,6 +36,7 @@ also figure #2 (OLS slides p. 15)
 
 The main differences to the timer wheel, which holds the armed timer_list type
 timers are:
+
        - time ordered enqueueing into a rb-tree
        - independent of ticks (the processing is based on nanoseconds)
 
@@ -55,7 +57,8 @@ merged into the 2.6.18 kernel.
 
 Further information about the Generic Time Of Day framework is available in the
 OLS 2005 Proceedings Volume 1:
-http://www.linuxsymposium.org/2005/linuxsymposium_procv1.pdf
+
+	http://www.linuxsymposium.org/2005/linuxsymposium_procv1.pdf
 
 The paper "We Are Not Getting Any Younger: A New Approach to Time and
 Timers" was written by J. Stultz, D.V. Hart, & N. Aravamudan.
@@ -100,6 +103,7 @@ accounting, profiling, and high resolution timers.
 
 The management layer assigns one or more of the following functions to a clock
 event device:
+
       - system global periodic tick (jiffies update)
       - cpu local update_process_times
       - cpu local profiling
@@ -244,6 +248,3 @@ extended to x86_64 and ARM already. Initial (work in progress) support is also
 available for MIPS and PowerPC.
 
 	  Thomas, Ingo
-
-
-
diff --git a/Documentation/timers/hpet.txt b/Documentation/timers/hpet.txt
index 895345ec513b..c9d05d3caaca 100644
--- a/Documentation/timers/hpet.txt
+++ b/Documentation/timers/hpet.txt
@@ -1,4 +1,6 @@
-		High Precision Event Timer Driver for Linux
+===========================================
+High Precision Event Timer Driver for Linux
+===========================================
 
 The High Precision Event Timer (HPET) hardware follows a specification
 by Intel and Microsoft, revision 1.
diff --git a/Documentation/timers/hrtimers.txt b/Documentation/timers/hrtimers.txt
index 588d85724f10..c1c20a693e8f 100644
--- a/Documentation/timers/hrtimers.txt
+++ b/Documentation/timers/hrtimers.txt
@@ -1,6 +1,6 @@
-
+======================================================
 hrtimers - subsystem for high-resolution kernel timers
-----------------------------------------------------
+======================================================
 
 This patch introduces a new subsystem for high-resolution kernel timers.
 
@@ -146,7 +146,7 @@ the clock_getres() interface. This will return whatever real resolution
 a given clock has - be it low-res, high-res, or artificially-low-res.
 
 hrtimers - testing and verification
-----------------------------------
+-----------------------------------
 
 We used the high-resolution clock subsystem ontop of hrtimers to verify
 the hrtimer implementation details in praxis, and we also ran the posix
diff --git a/Documentation/timers/timekeeping.txt b/Documentation/timers/timekeeping.txt
index 2d1732b0a868..f83e98852e2c 100644
--- a/Documentation/timers/timekeeping.txt
+++ b/Documentation/timers/timekeeping.txt
@@ -1,5 +1,6 @@
+===========================================================
 Clock sources, Clock events, sched_clock() and delay timers
------------------------------------------------------------
+===========================================================
 
 This document tries to briefly explain some basic kernel timekeeping
 abstractions. It partly pertains to the drivers usually found in
diff --git a/Documentation/timers/timers-howto.txt b/Documentation/timers/timers-howto.txt
index 038f8c77a076..7e3167bec2b1 100644
--- a/Documentation/timers/timers-howto.txt
+++ b/Documentation/timers/timers-howto.txt
@@ -1,5 +1,6 @@
+===================================================================
 delays - Information on the various kernel delay / sleep mechanisms
--------------------------------------------------------------------
+===================================================================
 
 This document seeks to answer the common question: "What is the
 RightWay (TM) to insert a delay?"
@@ -17,7 +18,7 @@ code in an atomic context?"  This should be followed closely by "Does
 it really need to delay in atomic context?" If so...
 
 ATOMIC CONTEXT:
-	You must use the *delay family of functions. These
+	You must use the `*delay` family of functions. These
 	functions use the jiffie estimation of clock speed
 	and will busy wait for enough loop cycles to achieve
 	the desired delay:
@@ -35,21 +36,26 @@ ATOMIC CONTEXT:
 	be refactored to allow for the use of msleep.
 
 NON-ATOMIC CONTEXT:
-	You should use the *sleep[_range] family of functions.
+	You should use the `*sleep[_range]` family of functions.
 	There are a few more options here, while any of them may
 	work correctly, using the "right" sleep function will
 	help the scheduler, power management, and just make your
 	driver better :)
 
 	-- Backed by busy-wait loop:
+
 		udelay(unsigned long usecs)
+
 	-- Backed by hrtimers:
+
 		usleep_range(unsigned long min, unsigned long max)
+
 	-- Backed by jiffies / legacy_timers
+
 		msleep(unsigned long msecs)
 		msleep_interruptible(unsigned long msecs)
 
-	Unlike the *delay family, the underlying mechanism
+	Unlike the `*delay` family, the underlying mechanism
 	driving each of these calls varies, thus there are
 	quirks you should be aware of.
 
@@ -70,6 +76,7 @@ NON-ATOMIC CONTEXT:
 		- Why not msleep for (1ms - 20ms)?
 			Explained originally here:
 				http://lkml.org/lkml/2007/8/3/250
+
 			msleep(1~20) may not do what the caller intends, and
 			will often sleep longer (~20 ms actual sleep for any
 			value given in the 1~20ms range). In many cases this
-- 
2.20.1

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