add script to help setup performance measuring in linux (#12)

motivation: performance tuning

changes: add script with setup code and example for running strace and perf

Author: tomerd

scripts/linux_performance_setup.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+
+# docker run --cap-add SYS_ADMIN -it -v `pwd`:/code -w /code swift:5.1 bash
+
+apt-get update
+apt-get install -y vim htop strace linux-tools-common linux-tools-generic
+
+cd /usr/bin
+rm -rf perf
+ln -s /usr/lib/linux-tools/4.15.0-88-generic/perf perf
+cd -
+
+cd build
+git clone https://github.com/brendangregg/FlameGraph.git
+cd -
+
+# build the code in relase mode with debug symbols
+# swift build -c release -Xswiftc -g
+#
+# run the server
+# (.build/release/MockServer) &
+#
+# strace
+# export MAX_REQUESTS=10000
+# strace -o .build/strace-c-string-$MAX_REQUESTS -c .build/release/SwiftAwsLambdaStringSample
+# strace -o .build/strace-ffftt-string-$MAX_REQUESTS -fftt .build/release/SwiftAwsLambdaStringSample
+#
+# perf
+# export MAX_REQUESTS=10000
+# perf record -o .build/perf-$MAX_REQUESTS.data -g .build/release/SwiftAwsLambdaStringSample dward
+# perf script -i .build/perf-$MAX_REQUESTS.data | .build/FlameGraph/stackcollapse-perf.pl | swift-demangle | .build/FlameGraph/flamegraph.pl > .build/flamegraph-$MAX_REQUESTS.svg