configure: test for functional readline more carefully

[bup.git] / Documentation / bup-memtest.md

diff --git a/Documentation/bup-memtest.md b/Documentation/bup-memtest.md
index 108a5a1328fe97f0df5fb771ab3c5af8632b0194..d87e9748df6fd7b5d9f822a1984f27bf04e065c8 100644 (file)
--- a/Documentation/bup-memtest.md
+++ b/Documentation/bup-memtest.md
@@ -28,24 +28,35 @@ what causes an increase in the VmRSS column.
 
 # OPTIONS
 
--n, --number=*number*
+-n, \--number=*number*
 :   set the number of objects to search for during each
     cycle (ie. before printing a line of output)
     
--c, --cycles=*cycles*
+-c, \--cycles=*cycles*
 :   set the number of cycles (ie. the number of lines of
     output after the first).  The first line of output is
     always 0 (ie. the baseline before searching for any
     objects).
     
---ignore-midx
+\--ignore-midx
 :   ignore any `.midx` files created by `bup midx`.  This
     allows you to compare memory performance with and
     without using midx.
-
-
-# EXAMPLE
-
+    
+\--existing
+:   search for existing objects instead of searching for
+    random nonexistent ones.  This can greatly affect
+    memory usage and performance.  Note that most of the
+    time, `bup save` spends most of its time searching for
+    nonexistent objects, since existing ones are probably
+    in unmodified files that we won't be trying to back up
+    anyway.  So the default behaviour reflects real bup
+    performance more accurately.  But you might want this
+    option anyway just to make sure you haven't made
+    searching for existing objects much worse than before.
+
+
+# EXAMPLES
     $ bup memtest -n300 -c5
     PackIdxList: using 1 index.
                    VmSize      VmRSS     VmData      VmStk