coccicheck: span checks across CPUs

This adds parallelism by default to the "coccicheck" target using
spatch's "-max" and "-index" arguments.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>

diff --git a/Documentation/coccinelle.txt b/Documentation/coccinelle.txt
index 18de785..408439d 100644 (file)
--- a/Documentation/coccinelle.txt
+++ b/Documentation/coccinelle.txt
@@ -91,6 +91,11 @@ To enable verbose messages set the V= variable, for example:
 
    make coccicheck MODE=report V=1
 
+By default, coccicheck tries to run as parallel as possible. To change
+the parallelism, set the J= variable. For example, to run across 4 CPUs:
+
+   make coccicheck MODE=report J=4
+
 
  Using Coccinelle with a single semantic patch
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

diff --git a/scripts/coccicheck b/scripts/coccicheck
index 9d8780c..ad8e8ff 100755 (executable)
--- a/scripts/coccicheck
+++ b/scripts/coccicheck
@@ -2,15 +2,24 @@
 
 SPATCH="`which ${SPATCH:=spatch}`"
 
+trap kill_running SIGTERM SIGINT
+declare -a SPATCH_PID
+
 # The verbosity may be set by the environmental parameter V=
 # as for example with 'make V=1 coccicheck'
 
 if [ -n "$V" -a "$V" != "0" ]; then
-       VERBOSE=1
+       VERBOSE="$V"
 else
        VERBOSE=0
 fi
 
+if [ -z "$J" ]; then
+       NPROC=$(getconf _NPROCESSORS_ONLN)
+else
+       NPROC="$J"
+fi
+
 FLAGS="$SPFLAGS -very_quiet"
 
 # spatch only allows include directories with the syntax "-I include"
@@ -69,12 +78,28 @@ if [ "$ONLINE" = "0" ] ; then
 fi
 
 run_cmd() {
+       local i
        if [ $VERBOSE -ne 0 ] ; then
-               echo "Running: $@"
+               echo "Running ($NPROC in parallel): $@"
        fi
-       eval $@
+       for i in $(seq 0 $(( NPROC - 1)) ); do
+               eval "$@ -max $NPROC -index $i &"
+               SPATCH_PID[$i]=$!
+               if [ $VERBOSE -eq 2 ] ; then
+                       echo "${SPATCH_PID[$i]} running"
+               fi
+       done
+       wait
 }
 
+kill_running() {
+       for i in $(seq $(( NPROC - 1 )) ); do
+               if [ $VERBOSE -eq 2 ] ; then
+                       echo "Killing ${SPATCH_PID[$i]}"
+               fi
+               kill ${SPATCH_PID[$i]} 2>/dev/null
+       done
+}
 
 coccinelle () {
     COCCI="$1"