Re: [PATCH v3 3/8] coccicheck: enable parmap support

[Julia Lawall <julia.lawall@lip6.fr>]

On Tue, 21 Jun 2016, Luis R. Rodriguez wrote:

> Coccinelle has had parmap support since 1.0.2, this means
> it supports --jobs, enabling built-in multithreaded functionality,
> instead of needing one to script it out. Just look for --jobs
> in the help output to determine if this is supported.
> 
> Also enable the load balancing to be dynamic, so that if a
> thread finishes early we keep feeding it.
> 
> Note: now that we have all things handled for us, redirect stderr to
> stdout as well to capture any possible errors or warnings issued by
> coccinelle.
> 
> If --jobs is not supported we fallback to the old mechanism.
> This also now accepts DEBUG_FILE= to specify where you want
> stderr to be redirected to, by default we redirect stderr to
> /dev/null.

Why do you want to do something different for standard error in the parmap 
and nonparmap case?

julia


> Also since while at it propagate back into the shell script any
> coccinelle error code. When used in serialized mode where all cocci
> files are run this also stops processing if an error has occured.
> This lets us handle some errors in coccinelle cocci files and if
> they bail out we should inspect the errors. This will be more
> useful later to help annotate coccinelle version dependency
> requirements. This will let you run only SmPL files that your
> system supports.
> 
> As a small example, prior to this change, on an 8-core system:
> 
> Before:
> 
> $ export COCCI=scripts/coccinelle/free/kfree.cocci
> $ time make coccicheck MODE=report DEBUG_FILE=cocci.err
> ...
> 
> real    29m14.912s
> user    103m1.796s
> sys     0m4.464s
> 
> After:
> 
> real    16m22.435s
> user    128m30.060s
> sys     0m2.712s
> 
> v3:
> 
> o move USE_JOBS to avoid being overriden
> 
> v2:
> 
> o redirect coccinelle stderr to /dev/null by default and
>   only if DEBUG_FILE is used do we pass it to a file
> o fix typo of paramap/parmap
> 
> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
> ---
>  scripts/coccicheck | 41 ++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 38 insertions(+), 3 deletions(-)
> 
> diff --git a/scripts/coccicheck b/scripts/coccicheck
> index 5319fae910b4..a77f0f246405 100755
> --- a/scripts/coccicheck
> +++ b/scripts/coccicheck
> @@ -12,8 +12,8 @@ if [ ! -x "$SPATCH" ]; then
>      exit 1
>  fi
>  
> -trap kill_running SIGTERM SIGINT
> -declare -a SPATCH_PID
> +USE_JOBS="no"
> +$SPATCH --help | grep "\-\-jobs" > /dev/null && USE_JOBS="yes"
>  
>  # The verbosity may be set by the environmental parameter V=
>  # as for example with 'make V=1 coccicheck'
> @@ -56,6 +56,14 @@ if [ "$KBUILD_EXTMOD" != "" ] ; then
>      OPTIONS="--patch $srctree $OPTIONS"
>  fi
>  
> +# You can override by using SPFLAGS
> +if [ "$USE_JOBS" = "no" ]; then
> +	trap kill_running SIGTERM SIGINT
> +	declare -a SPATCH_PID
> +else
> +	OPTIONS="$OPTIONS --jobs $NPROC --chunksize 1"
> +fi
> +
>  if [ "$MODE" = "" ] ; then
>      if [ "$ONLINE" = "0" ] ; then
>  	echo 'You have not explicitly specified the mode to use. Using default "report" mode.'
> @@ -82,7 +90,26 @@ if [ "$ONLINE" = "0" ] ; then
>      echo ''
>  fi
>  
> -run_cmd() {
> +run_cmd_parmap() {
> +	if [ $VERBOSE -ne 0 ] ; then
> +		echo "Running ($NPROC in parallel): $@"
> +	fi
> +	if [ "$DEBUG_FILE" != "/dev/null" -a "$DEBUG_FILE" != "" ]; then
> +		if [ -f $DEBUG_FILE ]; then
> +			echo "Debug file $DEBUG_FILE exists, bailing"
> +			exit
> +		fi
> +	else
> +		DEBUG_FILE="/dev/null"
> +	fi
> +	$@ 2>$DEBUG_FILE
> +	if [[ $? -ne 0 ]]; then
> +		echo "coccicheck failed"
> +		exit $?
> +	fi
> +}
> +
> +run_cmd_old() {
>  	local i
>  	if [ $VERBOSE -ne 0 ] ; then
>  		echo "Running ($NPROC in parallel): $@"
> @@ -97,6 +124,14 @@ run_cmd() {
>  	wait
>  }
>  
> +run_cmd() {
> +	if [ "$USE_JOBS" = "yes" ]; then
> +		run_cmd_parmap $@
> +	else
> +		run_cmd_old $@
> +	fi
> +}
> +
>  kill_running() {
>  	for i in $(seq 0 $(( NPROC - 1 )) ); do
>  		if [ $VERBOSE -eq 2 ] ; then
> -- 
> 2.8.2
> 
>