test: try to determine QEMU_SMP dynamically

If the QEMU_SMP value has not been explicitly set, try to determine it
from the number of online CPUs using the nproc utility. If this approach
fails, fall back to the default value QEMU_SMP=1.

This change should significantly help when running integration tests
under QEMU on multicore systems.

diff --git a/test/test-functions b/test/test-functions
index a936202e4a79baf3682b814fe6ce54b4ba3f0eb9..d8a3502a4ada02d3f33881f517117c7b38a4444b 100644 (file)
--- a/test/test-functions
+++ b/test/test-functions
@@ -134,7 +134,16 @@ run_qemu() {
         fi
     fi
 
-    [ "$QEMU_SMP" ]   || QEMU_SMP=1
+    # If QEMU_SMP was not explicitly set, try to determine the value 'dynamically'
+    # i.e. use the number of online CPUs on the host machine. If the nproc utility
+    # is not installed or there's some other error when calling it, fall back
+    # to the original value (QEMU_SMP=1).
+    if ! [ "$QEMU_SMP" ]; then
+        if ! QEMU_SMP=$(nproc); then
+            dwarn "nproc utility is not installed, falling back to QEMU_SMP=1"
+            QEMU_SMP=1
+        fi
+    fi
 
     find_qemu_bin || return 1