Add crossreference from pcreperform to pcrestack.

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@502 2f5784b3-3f2a-0410-8824-cb99058d5e15

1 files changed, 22 insertions, 6 deletions

diff --git a/doc/pcreperform.3 b/doc/pcreperform.3
index 915f7b7..59b63b8 100644
--- a/doc/pcreperform.3
+++ b/doc/pcreperform.3
@@ -8,14 +8,15 @@ Two aspects of performance are discussed below: memory usage and processing
 time. The way you express your pattern as a regular expression can affect both
 of them.
 .
-.SH "MEMORY USAGE"
+.SH "COMPILED PATTERN MEMORY USAGE"
 .rs
 .sp
 Patterns are compiled by PCRE into a reasonably efficient byte code, so that
 most simple patterns do not use much memory. However, there is one case where
-memory usage can be unexpectedly large. When a parenthesized subpattern has a
-quantifier with a minimum greater than 1 and/or a limited maximum, the whole
-subpattern is repeated in the compiled code. For example, the pattern
+the memory usage of a compiled pattern can be unexpectedly large. If a
+parenthesized subpattern has a quantifier with a minimum greater than 1 and/or
+a limited maximum, the whole subpattern is repeated in the compiled code. For
+example, the pattern
 .sp
   (abc|def){2,4}
 .sp
@@ -63,6 +64,21 @@ pattern. Nevertheless, if the atomic grouping is not a problem and the loss of
 speed is acceptable, this kind of rewriting will allow you to process patterns
 that PCRE cannot otherwise handle.
 .
+.
+.SH "STACK USAGE AT RUN TIME"
+.rs
+.sp
+When \fBpcre_exec()\fP is used for matching, certain kinds of pattern can cause
+it to use large amounts of the process stack. In some environments the default
+process stack is quite small, and if it runs out the result is often SIGSEGV.
+This issue is probably the most frequently raised problem with PCRE. Rewriting
+your pattern can often help. The
+.\" HREF
+\fBpcrestack\fP
+.\"
+documentation discusses this issue in detail.
+.
+.
 .SH "PROCESSING TIME"
 .rs
 .sp
@@ -148,6 +164,6 @@ Cambridge CB2 3QH, England.
 .rs
 .sp
 .nf
-Last updated: 06 March 2007
-Copyright (c) 1997-2007 University of Cambridge.
+Last updated: 07 March 2010
+Copyright (c) 1997-2010 University of Cambridge.
 .fi