Simplified counting CPUs.

src/scripts/build_kernel.sh

 #! /bin/sh
 
 # Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This script contains the set of commands to build a kernel package.
 #
 # If successful, a new linux-image-*.deb file will appear in the specified
 # output directory.
@@ skipping 108 matching lines @@
 rm -f "../${PACKAGE}"
 rm -f "${FLAGS_output_root}"/linux-image-*.deb
 
 # Speed up compilation by running parallel jobs.
 if [ ! -e "/proc/cpuinfo" ]
 then
     # default to a reasonable level
     CONCURRENCY_LEVEL=2
 else
     # speed up compilation by running #cpus * 2 simultaneous jobs
-    CONCURRENCY_LEVEL=$(($(cat /proc/cpuinfo | grep "processor" | wc -l) * 2))
+    CONCURRENCY_LEVEL=$(($(grep -c "^processor" /proc/cpuinfo) * 2))
 fi
 
 # Build the kernel and make package. "setarch" is used so that scripts which
 # detect architecture (like the "oldconfig" rule in kernel Makefile) don't get
 # confused when cross-compiling.
 make-kpkg clean
 MAKEFLAGS="CONCURRENCY_LEVEL=$CONCURRENCY_LEVEL" \
           setarch $ARCH make-kpkg \
           --append-to-version="-$CHROMEOS_TAG" --revision="$FLAGS_revision" \
           --arch="$ARCH" \
           --rootcmd fakeroot \
           --config oldconfig \
           --initrd --bzImage kernel_image
 
 # make-kpkg dumps the newly created package in the parent directory
 if [ -e "../${PACKAGE}" ]
 then
     mv "../${PACKAGE}" "${FLAGS_output_root}"
     echo "Kernel build successful, check ${FLAGS_output_root}/${PACKAGE}"
 else
     echo "Kernel build failed"
     exit 1
 fi