ceph.spec.in: derive _smp_ncpus and use it for -DBOOST_J

Signed-off-by: Dan Mick <dan.mick@redhat.com>

ceph.spec.in

@@ -785,6 +785,11 @@ env | sort
 %endif
 %endif
 
+# unlimit _smp_mflags in system macro if not set above
+%define _smp_ncpus_max 0
+# extract the number of processors for use with cmake
+%define _smp_ncpus %(echo %{_smp_mflags} | sed 's/-j//')
+
 mkdir build
 cd build
 cmake .. \
@@ -823,8 +828,9 @@ cmake .. \
 %endif
     $CEPH_EXTRA_CMAKE_ARGS \
 %if 0%{with ocf}
-    -DWITH_OCF=ON
+    -DWITH_OCF=ON \
 %endif
+    -DBOOST_J=%{_smp_ncpus}
 
 make %{?_smp_mflags}