docs: accounting: convert to ReST

Rename the accounting documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/accounting/cgroupstats.rst

@@ -1,3 +1,7 @@
+==================
+Control Groupstats
+==================
+
 Control Groupstats is inspired by the discussion at
 http://lkml.org/lkml/2007/4/11/187 and implements per cgroup statistics as
 suggested by Andrew Morton in http://lkml.org/lkml/2007/4/11/263.
@@ -19,9 +23,9 @@ about tasks blocked on I/O. If CONFIG_TASK_DELAY_ACCT is disabled, this
 information will not be available.
 
 To extract cgroup statistics a utility very similar to getdelays.c
-has been developed, the sample output of the utility is shown below
+has been developed, the sample output of the utility is shown below::
 
-~/balbir/cgroupstats # ./getdelays  -C "/sys/fs/cgroup/a"
-sleeping 1, blocked 0, running 1, stopped 0, uninterruptible 0
-~/balbir/cgroupstats # ./getdelays  -C "/sys/fs/cgroup"
-sleeping 155, blocked 0, running 1, stopped 0, uninterruptible 2
+  ~/balbir/cgroupstats # ./getdelays  -C "/sys/fs/cgroup/a"
+  sleeping 1, blocked 0, running 1, stopped 0, uninterruptible 0
+  ~/balbir/cgroupstats # ./getdelays  -C "/sys/fs/cgroup"
+  sleeping 155, blocked 0, running 1, stopped 0, uninterruptible 2

Documentation/accounting/delay-accounting.rst

@@ -1,5 +1,6 @@
+================
 Delay accounting
-----------------
+================
 
 Tasks encounter delays in execution when they wait
 for some kernel resource to become available e.g. a
@@ -39,7 +40,9 @@ in detail in a separate document in this directory. Taskstats returns a
 generic data structure to userspace corresponding to per-pid and per-tgid
 statistics. The delay accounting functionality populates specific fields of
 this structure. See
+
      include/linux/taskstats.h
+
 for a description of the fields pertaining to delay accounting.
 It will generally be in the form of counters returning the cumulative
 delay seen for cpu, sync block I/O, swapin, memory reclaim etc.
@@ -61,13 +64,16 @@ also serves as an example of using the taskstats interface.
 Usage
 -----
 
-Compile the kernel with
+Compile the kernel with::
+
 	CONFIG_TASK_DELAY_ACCT=y
 	CONFIG_TASKSTATS=y
 
 Delay accounting is enabled by default at boot up.
-To disable, add
+To disable, add::
+
    nodelayacct
+
 to the kernel boot options. The rest of the instructions
 below assume this has not been done.
 
@@ -78,40 +84,43 @@ The utility also allows a given command to be
 executed and the corresponding delays to be
 seen.
 
-General format of the getdelays command
+General format of the getdelays command::
 
-getdelays [-t tgid] [-p pid] [-c cmd...]
+	getdelays [-t tgid] [-p pid] [-c cmd...]
 
 
-Get delays, since system boot, for pid 10
-# ./getdelays -p 10
-(output similar to next case)
+Get delays, since system boot, for pid 10::
 
-Get sum of delays, since system boot, for all pids with tgid 5
-# ./getdelays -t 5
+	# ./getdelays -p 10
+	(output similar to next case)
+
+Get sum of delays, since system boot, for all pids with tgid 5::
+
+	# ./getdelays -t 5
 
 
-CPU	count	real total	virtual total	delay total
+	CPU	count	real total	virtual total	delay total
 		7876	92005750	100000000	24001500
-IO	count	delay total
+	IO	count	delay total
 		0	0
-SWAP	count	delay total
+	SWAP	count	delay total
 		0	0
-RECLAIM	count	delay total
+	RECLAIM	count	delay total
 		0	0
 
-Get delays seen in executing a given simple command
-# ./getdelays -c ls /
+Get delays seen in executing a given simple command::
 
-bin   data1  data3  data5  dev  home  media  opt   root  srv        sys  usr
-boot  data2  data4  data6  etc  lib   mnt    proc  sbin  subdomain  tmp  var
+  # ./getdelays -c ls /
+
+  bin   data1  data3  data5  dev  home  media  opt   root  srv        sys  usr
+  boot  data2  data4  data6  etc  lib   mnt    proc  sbin  subdomain  tmp  var
 
 
-CPU	count	real total	virtual total	delay total
+  CPU	count	real total	virtual total	delay total
 	6	4000250		4000000		0
-IO	count	delay total
+  IO	count	delay total
 	0	0
-SWAP	count	delay total
+  SWAP	count	delay total
 	0	0
-RECLAIM	count	delay total
+  RECLAIM	count	delay total
 	0	0

Documentation/accounting/index.rst

@@ -0,0 +1,14 @@
+:orphan:
+
+==========
+Accounting
+==========
+
+.. toctree::
+   :maxdepth: 1
+
+   cgroupstats
+   delay-accounting
+   psi
+   taskstats
+   taskstats-struct

Documentation/accounting/psi.rst

@@ -35,14 +35,14 @@ Pressure interface
 Pressure information for each resource is exported through the
 respective file in /proc/pressure/ -- cpu, memory, and io.
 
-The format for CPU is as such:
+The format for CPU is as such::
 
-some avg10=0.00 avg60=0.00 avg300=0.00 total=0
+	some avg10=0.00 avg60=0.00 avg300=0.00 total=0
 
-and for memory and IO:
+and for memory and IO::
 
-some avg10=0.00 avg60=0.00 avg300=0.00 total=0
-full avg10=0.00 avg60=0.00 avg300=0.00 total=0
+	some avg10=0.00 avg60=0.00 avg300=0.00 total=0
+	full avg10=0.00 avg60=0.00 avg300=0.00 total=0
 
 The "some" line indicates the share of time in which at least some
 tasks are stalled on a given resource.
@@ -77,9 +77,9 @@ To register a trigger user has to open psi interface file under
 /proc/pressure/ representing the resource to be monitored and write the
 desired threshold and time window. The open file descriptor should be
 used to wait for trigger events using select(), poll() or epoll().
-The following format is used:
+The following format is used::
 
-<some|full> <stall amount in us> <time window in us>
+	<some|full> <stall amount in us> <time window in us>
 
 For example writing "some 150000 1000000" into /proc/pressure/memory
 would add 150ms threshold for partial memory stall measured within
@@ -115,18 +115,20 @@ trigger  is closed.
 Userspace monitor usage example
 ===============================
 
-#include <errno.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <poll.h>
-#include <string.h>
-#include <unistd.h>
+::
 
-/*
+  #include <errno.h>
+  #include <fcntl.h>
+  #include <stdio.h>
+  #include <poll.h>
+  #include <string.h>
+  #include <unistd.h>
+
+  /*
    * Monitor memory partial stall with 1s tracking window size
    * and 150ms threshold.
    */
-int main() {
+  int main() {
 	const char trig[] = "some 150000 1000000";
 	struct pollfd fds;
 	int n;
@@ -165,7 +167,7 @@ int main() {
 	}
 
 	return 0;
-}
+  }
 
 Cgroup2 interface
 =================

Documentation/accounting/taskstats-struct.rst

@@ -1,5 +1,6 @@
+====================
 The struct taskstats
---------------------
+====================
 
 This document contains an explanation of the struct taskstats fields.
 
@@ -10,16 +11,24 @@ There are three different groups of fields in the struct taskstats:
     the common fields and basic accounting fields are collected for
     delivery at do_exit() of a task.
 2) Delay accounting fields
-    These fields are placed between
+    These fields are placed between::
+
 	/* Delay accounting fields start */
-    and
+
+    and::
+
 	/* Delay accounting fields end */
+
     Their values are collected if CONFIG_TASK_DELAY_ACCT is set.
 3) Extended accounting fields
-    These fields are placed between
+    These fields are placed between::
+
 	/* Extended accounting fields start */
-    and
+
+    and::
+
 	/* Extended accounting fields end */
+
     Their values are collected if CONFIG_TASK_XACCT is set.
 
 4) Per-task and per-thread context switch count statistics
@@ -31,10 +40,12 @@ There are three different groups of fields in the struct taskstats:
 Future extension should add fields to the end of the taskstats struct, and
 should not change the relative position of each field within the struct.
 
+::
 
-struct taskstats {
+  struct taskstats {
+
+1) Common and basic accounting fields::
 
-1) Common and basic accounting fields:
 	/* The version number of this struct. This field is always set to
 	 * TAKSTATS_VERSION, which is defined in <linux/taskstats.h>.
 	 * Each time the struct is changed, the value should be incremented.
@@ -83,7 +94,8 @@ struct taskstats {
 	__u64	ac_majflt;		/* Major Page Fault Count */
 
 
-2) Delay accounting fields:
+2) Delay accounting fields::
+
 	/* Delay accounting fields start
 	 *
 	 * All values, until the comment "Delay accounting fields end" are
@@ -134,7 +146,8 @@ struct taskstats {
 	/* version 1 ends here */
 
 
-3) Extended accounting fields
+3) Extended accounting fields::
+
 	/* Extended accounting fields start */
 
 	/* Accumulated RSS usage in duration of a task, in MBytes-usecs.
@@ -164,17 +177,23 @@ struct taskstats {
 
 	/* Extended accounting fields end */
 
-4) Per-task and per-thread statistics
+4) Per-task and per-thread statistics::
+
 	__u64	nvcsw;			/* Context voluntary switch counter */
 	__u64	nivcsw;			/* Context involuntary switch counter */
 
-5) Time accounting for SMT machines
+5) Time accounting for SMT machines::
+
 	__u64	ac_utimescaled;		/* utime scaled on frequency etc */
 	__u64	ac_stimescaled;		/* stime scaled on frequency etc */
 	__u64	cpu_scaled_run_real_total; /* scaled cpu_run_real_total */
 
-6) Extended delay accounting fields for memory reclaim
+6) Extended delay accounting fields for memory reclaim::
+
 	/* Delay waiting for memory reclaim */
 	__u64	freepages_count;
 	__u64	freepages_delay_total;
-}
+
+::
+
+  }

Documentation/accounting/taskstats.rst

@@ -1,5 +1,6 @@
+=============================
 Per-task statistics interface
------------------------------
+=============================
 
 
 Taskstats is a netlink-based interface for sending per-task and
@@ -65,7 +66,7 @@ taskstats.h file.
 
 The data exchanged between user and kernel space is a netlink message belonging
 to the NETLINK_GENERIC family and using the netlink attributes interface.
-The messages are in the format
+The messages are in the format::
 
     +----------+- - -+-------------+-------------------+
     | nlmsghdr | Pad |  genlmsghdr | taskstats payload |
@@ -167,15 +168,13 @@ extended and the number of cpus grows large.
 To avoid losing statistics, userspace should do one or more of the following:
 
 - increase the receive buffer sizes for the netlink sockets opened by
-listeners to receive exit data.
+  listeners to receive exit data.
 
 - create more listeners and reduce the number of cpus being listened to by
-each listener. In the extreme case, there could be one listener for each cpu.
-Users may also consider setting the cpu affinity of the listener to the subset
-of cpus to which it listens, especially if they are listening to just one cpu.
+  each listener. In the extreme case, there could be one listener for each cpu.
+  Users may also consider setting the cpu affinity of the listener to the subset
+  of cpus to which it listens, especially if they are listening to just one cpu.
 
 Despite these measures, if the userspace receives ENOBUFS error messages
 indicated overflow of receive buffers, it should take measures to handle the
 loss of data.
-
-----

Documentation/admin-guide/cgroup-v2.rst

@@ -1014,7 +1014,7 @@ All time durations are in microseconds.
 	A read-only nested-key file which exists on non-root cgroups.
 
 	Shows pressure stall information for CPU. See
-	Documentation/accounting/psi.txt for details.
+	Documentation/accounting/psi.rst for details.
 
 
 Memory
@@ -1355,7 +1355,7 @@ PAGE_SIZE multiple when read back.
 	A read-only nested-key file which exists on non-root cgroups.
 
 	Shows pressure stall information for memory. See
-	Documentation/accounting/psi.txt for details.
+	Documentation/accounting/psi.rst for details.
 
 
 Usage Guidelines
@@ -1498,7 +1498,7 @@ IO Interface Files
 	A read-only nested-key file which exists on non-root cgroups.
 
 	Shows pressure stall information for IO. See
-	Documentation/accounting/psi.txt for details.
+	Documentation/accounting/psi.rst for details.
 
 
 Writeback

init/Kconfig

@@ -550,7 +550,7 @@ config PSI
 	  have cpu.pressure, memory.pressure, and io.pressure files,
 	  which aggregate pressure stalls for the grouped tasks only.
 
-	  For more details see Documentation/accounting/psi.txt.
+	  For more details see Documentation/accounting/psi.rst.
 
 	  Say N if unsure.