diff --git a/mlir.spec b/mlir.spec
index 6c7f098..2550d0c 100644
--- a/mlir.spec
+++ b/mlir.spec
@@ -23,6 +23,47 @@ Source2: release-keys.asc
 
 Patch1: 0001-mlir-python-Reuse-the-library-directory.patch
 
+%{lua:
+
+-- Return the maximum number of parallel jobs a build can run based on the
+-- amount of maximum memory used per process (per_proc_mem).
+function print_max_procs(per_proc_mem)
+    local f = io.open("/proc/meminfo", "r")
+    local mem = 0
+    local nproc_str = nil
+    for line in f:lines() do
+        _, _, mem = string.find(line, "MemTotal:%s+(%d+)%s+kB")
+        if mem then
+           break
+        end
+    end
+    f:close()
+
+    local proc_handle = io.popen("nproc")
+    _, _, nproc_str = string.find(proc_handle:read("*a"), "(%d+)")
+    proc_handle:close()
+    local nproc = tonumber(nproc_str)
+    if nproc < 1 then
+        nproc = 1
+    end
+    local mem_mb = mem / 1024
+    local cpu = math.floor(mem_mb / per_proc_mem)
+    if cpu < 1 then
+        cpu = 1
+    end
+
+    if cpu > nproc then
+        cpu = nproc
+    end
+    print(cpu)
+end
+}
+
+# The amount of RAM used per process has been set by trial and error.
+# This number may increase/decrease from time to time and may require changes.
+# We prefer to be on the safe side in order to avoid spurious errors.
+%global _smp_mflags -j%{lua: print_max_procs(6144)}
+
 # Support for i686 upstream is unclear with lots of tests failling.
 ExcludeArch: i686