drm/amdkcl: limit number of tests to number of CPU

Limit the number of tests to be executed in parallel to the number of
processors available in the system. Checking for available memory may
cause a hang in the infinite loop on the system with small amount of
the system memory.

Signed-off-by: Slava Grigorev <slava.grigorev@amd.com>
Reviewed-by: Jeremy Newton <Jeremy.Newton@amd.com>
Reviewed-by: Slava Abramov <slava.abramov@amd.com>
Change-Id: I0217efee954b5a41cae2ad14cf2534f7032bae58

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 &