added 'perf-tools'

- signed-off-by: trimstray <trimstray@gmail.com>

README.md

@@ -210,6 +210,7 @@ Only main chapters:
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://github.com/strace/strace"><b>strace</b></a> - diagnostic, debugging and instructional userspace utility for Linux.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="http://dtrace.org/blogs/about/"><b>DTrace</b></a> - is a performance analysis and troubleshooting tool.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://en.wikipedia.org/wiki/Ltrace"><b>ltrace</b></a> - is a library call tracer, used to trace calls made by programs to library functions.<br>
+&nbsp;&nbsp;:small_orange_diamond: <a href="https://github.com/brendangregg/perf-tools"><b>perf-tools</b></a> - performance analysis tools based on Linux perf_events (aka perf) and ftrace.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://github.com/draios/sysdig"><b>sysdig</b></a> - system exploration and troubleshooting tool with first class support for containers.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="http://www.valgrind.org/"><b>Valgrind</b></a> - is an instrumentation framework for building dynamic analysis tools.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://nicolargo.github.io/glances/"><b>glances</b></a> - cross-platform system monitoring tool written in Python.<br>