Index: libcfa/src/concurrency/io/call.cfa.in
===================================================================
--- libcfa/src/concurrency/io/call.cfa.in	(revision 90a812553b6fb7bc8cf5dadc34f305f3df56721e)
+++ libcfa/src/concurrency/io/call.cfa.in	(revision 7ce88736e34bf185c4d55149f3117c28e91f9106)
@@ -34,4 +34,5 @@
 #include "kernel.hfa"
 #include "io/types.hfa"
+#include "stats.hfa"
 
 //=============================================================================================
@@ -226,5 +227,7 @@
 	async_{name}( future, {args}, submit_flags );
 
-	wait( future );
+	__attribute__((unused)) bool parked;
+	parked = wait( future );
+	__STATS__(false, if(!parked) io.submit.nblk += 1; )
 	if( future.result < 0 ) {{
 		errno = -future.result;
Index: libcfa/src/concurrency/io/setup.cfa
===================================================================
--- libcfa/src/concurrency/io/setup.cfa	(revision 90a812553b6fb7bc8cf5dadc34f305f3df56721e)
+++ libcfa/src/concurrency/io/setup.cfa	(revision 7ce88736e34bf185c4d55149f3117c28e91f9106)
@@ -229,6 +229,4 @@
 		#if !defined(CFA_WITH_IO_URING_IDLE)
 			// Step 4 : eventfd
-			// io_uring_register is so f*cking slow on some machine that it
-			// will never succeed if preemption isn't hard blocked
 			__cfadbg_print_safe(io_core, "Kernel I/O : registering %d for completion with ring %d\n", procfd, fd);
 
@@ -240,4 +238,19 @@
 			__cfadbg_print_safe(io_core, "Kernel I/O : registered %d for completion with ring %d\n", procfd, fd);
 		#endif
+
+		// #if defined(CFA_HAVE_IORING_REGISTER_IOWQ_MAX_WORKERS)
+		// 	// Step 5 : max worker count
+		// 	__cfadbg_print_safe(io_core, "Kernel I/O : lmiting max workers for ring %d\n", fd);
+
+		// 	unsigned int maxes[2];
+		// 	maxes[0] = 64; // max number of bounded workers (Regular files / block)
+		// 	maxes[1] = 64;  // max number of unbounded workers (IOSQE_ASYNC)
+		// 	int ret = syscall( __NR_io_uring_register, fd, IORING_REGISTER_IOWQ_MAX_WORKERS, maxes, 2);
+		// 	if (ret < 0) {
+		// 		abort("KERNEL ERROR: IO_URING MAX WORKER REGISTER - %s\n", strerror(errno));
+		// 	}
+
+		// 	__cfadbg_print_safe(io_core, "Kernel I/O : lmited max workers for ring %d\n", fd);
+		// #endif
 
 		// some paranoid checks