On Tue, 14 Nov 2017, Masahiro Yamada wrote: > The command "make -j8 C=1 CHECK=scripts/coccicheck COCCI=..." produces > lots of "coccicheck failed" error messages. > > Julia Lawall explained the Coccinelle behavior as follows: > "The problem on the Coccinelle side is that it uses a subdirectory > with the name of the semantic patch to store standard output and > standard error for the different threads. I didn't want to use a > name with the pid, so that one could easily find this information > while Coccinelle is running. Normally the subdirectory is cleaned > up when Coccinelle completes, so there is only one of them at a time. > Maybe it is best to just add the pid. There is the risk that these > subdirectories will accumulate if Coccinelle crashes in a way such > that they don't get cleaned up, but Coccinelle could print a warning > if it detects this case, rather than failing." > > When scripts/coccicheck is used as CHECK tool and -j option is given > to Make, the whole of build process runs in parallel. So, multiple > processes try to get access to the same subdirectory. > > I notice spatch creates the subdirectory only when it runs in parallel > (i.e. --jobs <N> is given and <N> is greater than 1). > > Setting NPROC=1 is a reasonable solution; spatch does not create the > subdirectory. Besides, ONLINE=1 mode takes a single file input for > each spatch invocation, so there is no reason to parallelize it in > the first place. > > Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> Acked-by: Julia Lawall <Julia.Lawall@xxxxxxx> > --- > > Changes in v4: > - Remove unnecessary comments. One line comment will be enough. > > Changes in v3: > - Set NPROC=1 because this is a more sensible solution > given that there is no reason to run coccinelle in parallel > for ONLINE=1 mode. > - Move J= option handling to a proper place. > - Add more detailed explanation > > Changes in v2: > - Grep '-j' instead of '--jobserver-auth'. > '--jobserver-*' is not a stable option flag. > Make 4.2 change '--jobserver-fds' into '--jobserver-auth' > - Add -q option to grep > > scripts/coccicheck | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > > diff --git a/scripts/coccicheck b/scripts/coccicheck > index 040a8b1..fefda40 100755 > --- a/scripts/coccicheck > +++ b/scripts/coccicheck > @@ -30,12 +30,6 @@ else > VERBOSE=0 > fi > > -if [ -z "$J" ]; then > - NPROC=$(getconf _NPROCESSORS_ONLN) > -else > - NPROC="$J" > -fi > - > FLAGS="--very-quiet" > > # You can use SPFLAGS to append extra arguments to coccicheck or override any > @@ -70,6 +64,9 @@ if [ "$C" = "1" -o "$C" = "2" ]; then > # Take only the last argument, which is the C file to test > shift $(( $# - 1 )) > OPTIONS="$COCCIINCLUDE $1" > + > + # No need to parallelize Coccinelle since this mode takes one input file. > + NPROC=1 > else > ONLINE=0 > if [ "$KBUILD_EXTMOD" = "" ] ; then > @@ -77,6 +74,12 @@ else > else > OPTIONS="--dir $KBUILD_EXTMOD $COCCIINCLUDE" > fi > + > + if [ -z "$J" ]; then > + NPROC=$(getconf _NPROCESSORS_ONLN) > + else > + NPROC="$J" > + fi > fi > > if [ "$KBUILD_EXTMOD" != "" ] ; then > -- > 2.7.4 > > -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
