diff --git a/drivers/gpu/drm/amd/dkms/m4/kernel.m4 b/drivers/gpu/drm/amd/dkms/m4/kernel.m4
index 3bcd090500e66..9f4555f11d836 100644
--- a/drivers/gpu/drm/amd/dkms/m4/kernel.m4
+++ b/drivers/gpu/drm/amd/dkms/m4/kernel.m4
@@ -668,22 +668,6 @@ AC_DEFUN([AC_KERNEL_CHECK_HEADERS], [
 	AC_CHECK_HEADERS([$1],[AS_TR_CPP([HAVE_$1])=1],,[-])
 ])
 
-dnl #
-dnl # AC_KERNEL_FREE_MEM
-dnl # return true if available memory >20%
-dnl #
-AC_DEFUN([AC_KERNEL_FREE_MEM], [
-	free_mem=$(free -t | awk '/^Total:/ {
-		printf("%d\n", $[4] / $[2] * 100)
-	}')
-
-	AS_IF([[[ $free_mem -gt 20 ]]], [
-		$1
-	], [
-		$2
-	])
-])
-
 dnl #
 dnl # AC_KERNEL_DO_BACKGROUND
 dnl # $1: contents to be executed
@@ -693,14 +677,16 @@ AC_DEFUN([AC_KERNEL_DO_BACKGROUND], [
 		AC_KERNEL_TMP_BUILD_DIR([$1])
 	}
 
-	while :
+	AC_CHECK_PROG(NPROC, nproc, yes)
+	AS_IF([test x"$NPROC" != x"yes"], [
+		ncpu=1
+	], [
+		ncpu=$(nproc)
+	])
+
+	while [[ $(jobs | wc -l) -gt $ncpu ]]
 	do
-		AC_KERNEL_FREE_MEM([rc=0], [rc=1])
-		if test $rc -ne 0; then :
-			sleep 1
-		else :
-			break
-		fi
+		sleep 0.1
 	done
 
 	do_background &