docs: convert docs to ReST and rename to *.rst

The conversion is actually:
  - add blank lines and indentation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

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>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 0 insertions, 223 deletions

diff --git a/Documentation/device-mapper/statistics.txt b/Documentation/device-mapper/statistics.txt
deleted file mode 100644
index 170ac02a1f50..000000000000
--- a/Documentation/device-mapper/statistics.txt
+++ /dev/null
@@ -1,223 +0,0 @@
-DM statistics
-=============
-
-Device Mapper supports the collection of I/O statistics on user-defined
-regions of a DM device.  If no regions are defined no statistics are
-collected so there isn't any performance impact.  Only bio-based DM
-devices are currently supported.
-
-Each user-defined region specifies a starting sector, length and step.
-Individual statistics will be collected for each step-sized area within
-the range specified.
-
-The I/O statistics counters for each step-sized area of a region are
-in the same format as /sys/block/*/stat or /proc/diskstats (see:
-Documentation/iostats.txt).  But two extra counters (12 and 13) are
-provided: total time spent reading and writing.  When the histogram
-argument is used, the 14th parameter is reported that represents the
-histogram of latencies.  All these counters may be accessed by sending
-the @stats_print message to the appropriate DM device via dmsetup.
-
-The reported times are in milliseconds and the granularity depends on
-the kernel ticks.  When the option precise_timestamps is used, the
-reported times are in nanoseconds.
-
-Each region has a corresponding unique identifier, which we call a
-region_id, that is assigned when the region is created.  The region_id
-must be supplied when querying statistics about the region, deleting the
-region, etc.  Unique region_ids enable multiple userspace programs to
-request and process statistics for the same DM device without stepping
-on each other's data.
-
-The creation of DM statistics will allocate memory via kmalloc or
-fallback to using vmalloc space.  At most, 1/4 of the overall system
-memory may be allocated by DM statistics.  The admin can see how much
-memory is used by reading
-/sys/module/dm_mod/parameters/stats_current_allocated_bytes
-
-Messages
-========
-
-    @stats_create <range> <step>
-                [<number_of_optional_arguments> <optional_arguments>...]
-                [<program_id> [<aux_data>]]
-
-        Create a new region and return the region_id.
-
-        <range>
-          "-" - whole device
-          "<start_sector>+<length>" - a range of <length> 512-byte sectors
-                                      starting with <start_sector>.
-
-        <step>
-          "<area_size>" - the range is subdivided into areas each containing
-                          <area_size> sectors.
-          "/<number_of_areas>" - the range is subdivided into the specified
-                                 number of areas.
-
-        <number_of_optional_arguments>
-          The number of optional arguments
-
-        <optional_arguments>
-          The following optional arguments are supported
-          precise_timestamps - use precise timer with nanosecond resolution
-                instead of the "jiffies" variable.  When this argument is
-                used, the resulting times are in nanoseconds instead of
-                milliseconds.  Precise timestamps are a little bit slower
-                to obtain than jiffies-based timestamps.
-          histogram:n1,n2,n3,n4,... - collect histogram of latencies.  The
-                numbers n1, n2, etc are times that represent the boundaries
-                of the histogram.  If precise_timestamps is not used, the
-                times are in milliseconds, otherwise they are in
-                nanoseconds.  For each range, the kernel will report the
-                number of requests that completed within this range. For
-                example, if we use "histogram:10,20,30", the kernel will
-                report four numbers a:b:c:d. a is the number of requests
-                that took 0-10 ms to complete, b is the number of requests
-                that took 10-20 ms to complete, c is the number of requests
-                that took 20-30 ms to complete and d is the number of
-                requests that took more than 30 ms to complete.
-
-        <program_id>
-          An optional parameter.  A name that uniquely identifies
-          the userspace owner of the range.  This groups ranges together
-          so that userspace programs can identify the ranges they
-          created and ignore those created by others.
-          The kernel returns this string back in the output of
-          @stats_list message, but it doesn't use it for anything else.
-          If we omit the number of optional arguments, program id must not
-          be a number, otherwise it would be interpreted as the number of
-          optional arguments.
-
-        <aux_data>
-          An optional parameter.  A word that provides auxiliary data
-          that is useful to the client program that created the range.
-          The kernel returns this string back in the output of
-          @stats_list message, but it doesn't use this value for anything.
-
-    @stats_delete <region_id>
-
-        Delete the region with the specified id.
-
-        <region_id>
-          region_id returned from @stats_create
-
-    @stats_clear <region_id>
-
-        Clear all the counters except the in-flight i/o counters.
-
-        <region_id>
-          region_id returned from @stats_create
-
-    @stats_list [<program_id>]
-
-        List all regions registered with @stats_create.
-
-        <program_id>
-          An optional parameter.
-          If this parameter is specified, only matching regions
-          are returned.
-          If it is not specified, all regions are returned.
-
-        Output format:
-          <region_id>: <start_sector>+<length> <step> <program_id> <aux_data>
-                precise_timestamps histogram:n1,n2,n3,...
-
-        The strings "precise_timestamps" and "histogram" are printed only
-        if they were specified when creating the region.
-
-    @stats_print <region_id> [<starting_line> <number_of_lines>]
-
-        Print counters for each step-sized area of a region.
-
-        <region_id>
-          region_id returned from @stats_create
-
-        <starting_line>
-          The index of the starting line in the output.
-          If omitted, all lines are returned.
-
-        <number_of_lines>
-          The number of lines to include in the output.
-          If omitted, all lines are returned.
-
-        Output format for each step-sized area of a region:
-
-          <start_sector>+<length> counters
-
-          The first 11 counters have the same meaning as
-          /sys/block/*/stat or /proc/diskstats.
-
-          Please refer to Documentation/iostats.txt for details.
-
-          1. the number of reads completed
-          2. the number of reads merged
-          3. the number of sectors read
-          4. the number of milliseconds spent reading
-          5. the number of writes completed
-          6. the number of writes merged
-          7. the number of sectors written
-          8. the number of milliseconds spent writing
-          9. the number of I/Os currently in progress
-          10. the number of milliseconds spent doing I/Os
-          11. the weighted number of milliseconds spent doing I/Os
-
-          Additional counters:
-          12. the total time spent reading in milliseconds
-          13. the total time spent writing in milliseconds
-
-    @stats_print_clear <region_id> [<starting_line> <number_of_lines>]
-
-        Atomically print and then clear all the counters except the
-        in-flight i/o counters.  Useful when the client consuming the
-        statistics does not want to lose any statistics (those updated
-        between printing and clearing).
-
-        <region_id>
-          region_id returned from @stats_create
-
-        <starting_line>
-          The index of the starting line in the output.
-          If omitted, all lines are printed and then cleared.
-
-        <number_of_lines>
-          The number of lines to process.
-          If omitted, all lines are printed and then cleared.
-
-    @stats_set_aux <region_id> <aux_data>
-
-        Store auxiliary data aux_data for the specified region.
-
-        <region_id>
-          region_id returned from @stats_create
-
-        <aux_data>
-          The string that identifies data which is useful to the client
-          program that created the range.  The kernel returns this
-          string back in the output of @stats_list message, but it
-          doesn't use this value for anything.
-
-Examples
-========
-
-Subdivide the DM device 'vol' into 100 pieces and start collecting
-statistics on them:
-
-  dmsetup message vol 0 @stats_create - /100
-
-Set the auxiliary data string to "foo bar baz" (the escape for each
-space must also be escaped, otherwise the shell will consume them):
-
-  dmsetup message vol 0 @stats_set_aux 0 foo\\ bar\\ baz
-
-List the statistics:
-
-  dmsetup message vol 0 @stats_list
-
-Print the statistics:
-
-  dmsetup message vol 0 @stats_print 0
-
-Delete the statistics:
-
-  dmsetup message vol 0 @stats_delete 0