proc.5: Small fixes to Peter Schiffer's /proc/PID/io patch

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man5/proc.5

@@ -59,7 +59,7 @@
 .\" to see what information could be imported from that file
 .\" into this file.
 .\"
-.TH PROC 5 2013-06-27 "Linux" "Linux Programmer's Manual"
+.TH PROC 5 2013-08-01 "Linux" "Linux Programmer's Manual"
 .SH NAME
 proc \- process information pseudo-file system
 .SH DESCRIPTION
@@ -352,7 +352,8 @@ file access mode and file status flags (see
 The files in this directory are readable only by the owner of the process.
 .TP
 .IR /proc/[pid]/io " (since kernel 2.6.20)"
-This file contains IO statistics for each running process, for example:
+.\" commit 7c3ab7381e79dfc7db14a67c6f4f3285664e1ec2
+This file contains I/O statistics for the process, for example:
 .in +4n
 .nf
 
@@ -369,75 +370,66 @@ cancelled_write_bytes: 0
 
 The fields are as follows:
 .RS
-.IP * 2
-.IR rchar :
-chars read
-
+.TP
+.IR rchar ": characters read"
 The number of bytes which this task has caused to be read from storage.
 This is simply the sum of bytes which this process passed to
 .BR read (2)
-and
-.BR pread (2).
-It includes things like tty IO and it is unaffected by whether or not actual
-physical disk IO was required (the read might have been satisfied from
+and similar system calls.
+It includes things such as terminal I/O and 
+is unaffected by whether or not actual
+physical disk I/O was required (the read might have been satisfied from
 pagecache).
-.IP *
-.IR wchar :
-chars written
-
+.TP
+.IR wchar ": characters written"
 The number of bytes which this task has caused, or shall cause to be written
 to disk.
 Similar caveats apply here as with
 .IR rchar .
-.IP *
-.IR syscr :
-read syscalls
-
-Attempt to count the number of read I/O operations, i.e. syscalls like
+.TP
+.IR syscr ": read syscalls"
+Attempt to count the number of read I/O operations\(emthat is,
+system calls such as
 .BR read (2)
 and
 .BR pread (2).
-.IP *
-.IR syscw :
-write syscalls
-
-Attempt to count the number of write I/O operations, i.e. syscalls like
+.TP
+.IR syscw ": write syscalls"
+Attempt to count the number of write I/O operations\(emthat is,
+system calls such as
 .BR write (2)
 and
 .BR pwrite (2).
-.IP *
-.IR read_bytes :
-bytes read
-
+.TP
+.IR read_bytes ": bytes read"
 Attempt to count the number of bytes which this process really did cause to
 be fetched from the storage layer.
 This is accurate for block-backed filesystems.
-.IP *
-.IR write_bytes :
-bytes written
-
+.TP
+.IR write_bytes ": bytes written"
 Attempt to count the number of bytes which this process caused to be sent to
 the storage layer.
-.IP *
+.TP
 .IR cancelled_write_bytes :
-
 The big inaccuracy here is truncate.
 If a process writes 1MB to a file and then deletes the file,
 it will in fact perform no writeout.
 But it will have been accounted as having caused 1MB of write.
-In other words: this field represents number of bytes which this process
+In other words: this field represents the number of bytes which this process
 caused to not happen, by truncating pagecache.
-A task can cause "negative" IO too.
+A task can cause "negative" I/O too.
 If this task truncates some dirty pagecache,
-some IO which another task has been accounted for
-(in its write_bytes) will not be happening.
+some I/O which another task has been accounted for
+(in its
+.IR write_bytes )
+will not be happening.
+.RE
 .IP
 .IR Note :
-
-At its current implementation state, this is a bit racy on 32-bit systems:
+In the current implementation, things are a bit racy on 32-bit systems:
 if process A reads process B's
 .I /proc/[pid]/io
-while process B is updating one of those 64-bit counters,
+while process B is updating one of these 64-bit counters,
 process A could see an intermediate result.
 .RE
 .TP