Index: src/benchmark/Makefile.am
===================================================================
--- src/benchmark/Makefile.am	(revision 1134b80884fbfefdfcca5d37cbd929da7706135d)
+++ src/benchmark/Makefile.am	(revision d56cc2199f40aba8cc9635ca8e888afdd3d18ab8)
@@ -96,23 +96,35 @@
 	ctxswitch-cfa_coroutine.run	\
 	ctxswitch-cfa_thread.run	\
+	ctxswitch-cfa_thread2.run	\
 	ctxswitch-upp_coroutine.run	\
 	ctxswitch-upp_thread.run	\
+	-ctxswitch-kos_fibre.run	\
+	-ctxswitch-kos_fibre2.run	\
 	ctxswitch-goroutine.run		\
 	ctxswitch-java_thread.run
 
+ctxswitch-pthread$(EXEEXT):
+	@@BACKEND_CC@ ctxswitch/pthreads.c     -DBENCH_N=50000000  -I. -lrt -pthread                    ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+
 ctxswitch-cfa_coroutine$(EXEEXT):
-	@${CC}        ctxswitch/cfa_cor.c   -DBENCH_N=50000000  -I. -nodebug -lrt -quiet @CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+	@${CC}        ctxswitch/cfa_cor.c      -DBENCH_N=50000000  -I. -nodebug -lrt -quiet @CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
 
 ctxswitch-cfa_thread$(EXEEXT):
-	@${CC}        ctxswitch/cfa_thrd.c  -DBENCH_N=50000000  -I. -nodebug -lrt -quiet @CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+	@${CC}        ctxswitch/cfa_thrd.c     -DBENCH_N=50000000  -I. -nodebug -lrt -quiet @CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+
+ctxswitch-cfa_thread2$(EXEEXT):
+	@${CC}        ctxswitch/cfa_thrd2.c    -DBENCH_N=50000000  -I. -nodebug -lrt -quiet @CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
 
 ctxswitch-upp_coroutine$(EXEEXT):
-	@u++          ctxswitch/upp_cor.cc  -DBENCH_N=50000000  -I. -nodebug -lrt -quiet             ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+	@u++          ctxswitch/upp_cor.cc     -DBENCH_N=50000000  -I. -nodebug -lrt -quiet             ${AM_CFLAGS} ${CFLAGS} ${ccflags}
 
 ctxswitch-upp_thread$(EXEEXT):
-	@u++          ctxswitch/upp_thrd.cc -DBENCH_N=50000000  -I. -nodebug -lrt -quiet             ${AM_CFLAGS} ${CFLAGS} ${ccflags}
-
-ctxswitch-pthread$(EXEEXT):
-	@@BACKEND_CC@ ctxswitch/pthreads.c  -DBENCH_N=50000000  -I. -lrt -pthread                    ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+	@u++          ctxswitch/upp_thrd.cc    -DBENCH_N=50000000  -I. -nodebug -lrt -quiet             ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+
+ctxswitch-kos_fibre$(EXEEXT):
+	@${CXX}       ctxswitch/kos_fibre.cpp  -DBENCH_N=50000000  -I. -I/home/tdelisle/software/KOS/src/ -g -O2 -lfibre -lpthread -lrt
+
+ctxswitch-kos_fibre2$(EXEEXT):
+	@${CXX}       ctxswitch/kos_fibre2.cpp -DBENCH_N=50000000  -I. -I/home/tdelisle/software/KOS/src/ -g -O2 -lfibre -lpthread -lrt
 
 ctxswitch-goroutine$(EXEEXT):
Index: src/benchmark/Makefile.in
===================================================================
--- src/benchmark/Makefile.in	(revision 1134b80884fbfefdfcca5d37cbd929da7706135d)
+++ src/benchmark/Makefile.in	(revision d56cc2199f40aba8cc9635ca8e888afdd3d18ab8)
@@ -509,23 +509,35 @@
 	ctxswitch-cfa_coroutine.run	\
 	ctxswitch-cfa_thread.run	\
+	ctxswitch-cfa_thread2.run	\
 	ctxswitch-upp_coroutine.run	\
 	ctxswitch-upp_thread.run	\
+	-ctxswitch-kos_fibre.run	\
+	-ctxswitch-kos_fibre2.run	\
 	ctxswitch-goroutine.run		\
 	ctxswitch-java_thread.run
 
+ctxswitch-pthread$(EXEEXT):
+	@@BACKEND_CC@ ctxswitch/pthreads.c     -DBENCH_N=50000000  -I. -lrt -pthread                    ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+
 ctxswitch-cfa_coroutine$(EXEEXT):
-	@${CC}        ctxswitch/cfa_cor.c   -DBENCH_N=50000000  -I. -nodebug -lrt -quiet @CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+	@${CC}        ctxswitch/cfa_cor.c      -DBENCH_N=50000000  -I. -nodebug -lrt -quiet @CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
 
 ctxswitch-cfa_thread$(EXEEXT):
-	@${CC}        ctxswitch/cfa_thrd.c  -DBENCH_N=50000000  -I. -nodebug -lrt -quiet @CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+	@${CC}        ctxswitch/cfa_thrd.c     -DBENCH_N=50000000  -I. -nodebug -lrt -quiet @CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+
+ctxswitch-cfa_thread2$(EXEEXT):
+	@${CC}        ctxswitch/cfa_thrd2.c    -DBENCH_N=50000000  -I. -nodebug -lrt -quiet @CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
 
 ctxswitch-upp_coroutine$(EXEEXT):
-	@u++          ctxswitch/upp_cor.cc  -DBENCH_N=50000000  -I. -nodebug -lrt -quiet             ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+	@u++          ctxswitch/upp_cor.cc     -DBENCH_N=50000000  -I. -nodebug -lrt -quiet             ${AM_CFLAGS} ${CFLAGS} ${ccflags}
 
 ctxswitch-upp_thread$(EXEEXT):
-	@u++          ctxswitch/upp_thrd.cc -DBENCH_N=50000000  -I. -nodebug -lrt -quiet             ${AM_CFLAGS} ${CFLAGS} ${ccflags}
-
-ctxswitch-pthread$(EXEEXT):
-	@@BACKEND_CC@ ctxswitch/pthreads.c  -DBENCH_N=50000000  -I. -lrt -pthread                    ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+	@u++          ctxswitch/upp_thrd.cc    -DBENCH_N=50000000  -I. -nodebug -lrt -quiet             ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+
+ctxswitch-kos_fibre$(EXEEXT):
+	@${CXX}       ctxswitch/kos_fibre.cpp  -DBENCH_N=50000000  -I. -I/home/tdelisle/software/KOS/src/ -g -O2 -lfibre -lpthread -lrt
+
+ctxswitch-kos_fibre2$(EXEEXT):
+	@${CXX}       ctxswitch/kos_fibre2.cpp -DBENCH_N=50000000  -I. -I/home/tdelisle/software/KOS/src/ -g -O2 -lfibre -lpthread -lrt
 
 ctxswitch-goroutine$(EXEEXT):
@@ -682,8 +694,8 @@
 
 compile-io$(EXEEXT):
-	@${CC} -quiet -fsyntax-only -w ../tests/io.c					@CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+	@${CC} -quiet -fsyntax-only -w ../tests/io1.c				@CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
 
 compile-monitor$(EXEEXT):
-	@${CC} -quiet -fsyntax-only -w ../tests/concurrent/monitor.c		@CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+	@${CC} -quiet -fsyntax-only -w ../tests/concurrent/monitor.c	@CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
 
 compile-operators$(EXEEXT):
@@ -694,5 +706,5 @@
 
 compile-typeof$(EXEEXT):
-	@${CC} -quiet -fsyntax-only -w ../tests/typeof.c				@CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
+	@${CC} -quiet -fsyntax-only -w ../tests/typeof.c			@CFA_FLAGS@ ${AM_CFLAGS} ${CFLAGS} ${ccflags}
 
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
Index: src/benchmark/ctxswitch/cfa_thrd2.c
===================================================================
--- src/benchmark/ctxswitch/cfa_thrd2.c	(revision d56cc2199f40aba8cc9635ca8e888afdd3d18ab8)
+++ src/benchmark/ctxswitch/cfa_thrd2.c	(revision d56cc2199f40aba8cc9635ca8e888afdd3d18ab8)
@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <thread>
+
+#include "bench.h"
+
+volatile bool done = false;
+
+thread Fibre {};
+
+void main(Fibre & this) {
+	while(!done) {
+		yield();
+	}
+}
+
+int main(int argc, char* argv[]) {
+	Fibre f1;
+  	BENCH(
+		for (size_t i = 0; i < n; i++) {
+			yield();
+		},
+		result
+	)
+
+	printf("%llu\n", result);
+	done = true;
+	return 0;
+}
Index: src/benchmark/ctxswitch/kos_fibre.cpp
===================================================================
--- src/benchmark/ctxswitch/kos_fibre.cpp	(revision d56cc2199f40aba8cc9635ca8e888afdd3d18ab8)
+++ src/benchmark/ctxswitch/kos_fibre.cpp	(revision d56cc2199f40aba8cc9635ca8e888afdd3d18ab8)
@@ -0,0 +1,14 @@
+#include <libfibre/fibre.h>
+
+#include "bench.h"
+
+int main(int argc, char* argv[]) {
+	BENCH(
+		for (size_t i = 0; i < n; i++) {
+			Fibre::yield();
+		},
+		result
+	)
+	printf("%llu\n", result);
+	return 0;
+}
Index: src/benchmark/ctxswitch/kos_fibre2.cpp
===================================================================
--- src/benchmark/ctxswitch/kos_fibre2.cpp	(revision d56cc2199f40aba8cc9635ca8e888afdd3d18ab8)
+++ src/benchmark/ctxswitch/kos_fibre2.cpp	(revision d56cc2199f40aba8cc9635ca8e888afdd3d18ab8)
@@ -0,0 +1,26 @@
+#include <libfibre/fibre.h>
+
+#include "bench.h"
+
+volatile bool done = false;
+
+static void f1main() {
+	while(!done) {
+		Fibre::yield();
+	}
+}
+
+int main(int argc, char* argv[]) {
+	Fibre* f1 = (new Fibre)->run(f1main);
+  	BENCH(
+		for (size_t i = 0; i < n; i++) {
+			Fibre::yield();
+		},
+		result
+	)
+	printf("%llu\n", result);
+	done = true;
+	Fibre::yield();
+	f1->join();
+	return 0;
+}