introducing man pages

man/cachedel.1

+.TH CACHEDEL "1" "March 2013" "cachedel" ""
+.SH NAME
+cachedel \- drop pagecache for a file
+.SH SYNOPSIS
+cachedel \fBfile\fR
+.SH DESCRIPTION
+Call fadvise(DONTNEED) on file

man/cachestats.1

+.TH CACHESTATS "1" "March 2013" "cachestats" ""
+.SH NAME
+cachestats \- print cache statistics for a file
+.SH SYNOPSIS
+cachestats [\-qv] \fBfile\fR
+.SH DESCRIPTION
+Print number of cached vs. not-cached pages.
+.SH OPTIONS
+.TP
+\fB\-v\fR "Verbose mode"
+Print verbose cache map, where each page that is present in the cache is
+marked with `x`.
+.TP
+\fB\-q\fR "Quiet mode"
+The exit status is 0 (success) if the file is fully cached.
+.SH EXAMPLE
+.EX
+$ cachestats \-v ~/somefile.mp3
+pages in cache: 85/114 (74.6%)  [filesize=453.5K, pagesize=4K]
+
+cache map:
+     0: |x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|
+    32: |x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|
+    64: |x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x|x| | | | | | | | | | | | |
+    96: | | | | | | | | | | | | | | | | | |x|
+.EE
+.SH SEE ALSO
+Also, you can use `vmstat 1` to view cache statistics.

man/nocache.1

+.TH NOCACHE "1" "March 2013" "nocache" ""
+.SH NAME
+nocache \- don't use Linux page cache on given command
+.SH SYNOPSIS
+nocache \fBcommand\fR [argument...]
+.SH DESCRIPTION
+The `nocache` tool tries to minimize the effect an application has on
+the Linux file system cache. This is done by intercepting the `open`
+and `close` system calls and calling `posix_fadvise` with the
+`POSIX_FADV_DONTNEED` parameter. Because the library remembers which
+pages (ie., 4K-blocks of the file) were already in file system cache
+when the file was opened, these will not be marked as "don't need",
+because other applications might need that, although they are not
+actively used (think: hot standby).
+
+Use case: backup processes that should not interfere with the present
+state of the cache.