| Message ID | 1510650290-3363-1-git-send-email-yamada.masahiro@socionext.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] coccinelle: fix parallel build with CHECK=scripts/coccicheck | expand |
> + > + # If -j option is given to Make, scripts/coccicheck runs in parallel. > + # If coccinelle also runs in parallel, it fails because multiple processes > + # try to get access to the same subdirectory that stores stdout/stderr. > + # No need to parallelize coccinelle in this case - this mode takes only > + # one file input. > + NPROC=1 Since I am also changing Coccinelle to avoid the problem, maybe it would be better to just remove the explanation sentence (If coccinelle also runs in parallel,...). julia
Hi Julia, 2017-11-14 18:49 GMT+09:00 Julia Lawall <julia.lawall@lip6.fr>: >> + >> + # If -j option is given to Make, scripts/coccicheck runs in parallel. >> + # If coccinelle also runs in parallel, it fails because multiple processes >> + # try to get access to the same subdirectory that stores stdout/stderr. >> + # No need to parallelize coccinelle in this case - this mode takes only >> + # one file input. >> + NPROC=1 > > Since I am also changing Coccinelle to avoid the problem, maybe it would > be better to just remove the explanation sentence (If coccinelle also runs > in parallel,...). > > julia OK. Which lines are unneeded? Is it OK to remove all the comments, then just add "NPROC=1"? -- Best Regards Masahiro Yamada
On Tue, 14 Nov 2017, Masahiro Yamada wrote: > Hi Julia, > > > 2017-11-14 18:49 GMT+09:00 Julia Lawall <julia.lawall@lip6.fr>: > >> + > >> + # If -j option is given to Make, scripts/coccicheck runs in parallel. > >> + # If coccinelle also runs in parallel, it fails because multiple processes > >> + # try to get access to the same subdirectory that stores stdout/stderr. > >> + # No need to parallelize coccinelle in this case - this mode takes only > >> + # one file input. > >> + NPROC=1 > > > > Since I am also changing Coccinelle to avoid the problem, maybe it would > > be better to just remove the explanation sentence (If coccinelle also runs > > in parallel,...). > > > > julia > > OK. Which lines are unneeded? > > Is it OK to remove all the comments, then just add "NPROC=1"? How about keeping "# No need to parallelize coccinelle in this case - this mode takes only one file input."? But if you think it is obvious, it would be ok to remove it also. Someone can always do git blame and read the commit message if they have questions. julia
2017-11-14 20:09 GMT+09:00 Julia Lawall <julia.lawall@lip6.fr>: > > > On Tue, 14 Nov 2017, Masahiro Yamada wrote: > >> Hi Julia, >> >> >> 2017-11-14 18:49 GMT+09:00 Julia Lawall <julia.lawall@lip6.fr>: >> >> + >> >> + # If -j option is given to Make, scripts/coccicheck runs in parallel. >> >> + # If coccinelle also runs in parallel, it fails because multiple processes >> >> + # try to get access to the same subdirectory that stores stdout/stderr. >> >> + # No need to parallelize coccinelle in this case - this mode takes only >> >> + # one file input. >> >> + NPROC=1 >> > >> > Since I am also changing Coccinelle to avoid the problem, maybe it would >> > be better to just remove the explanation sentence (If coccinelle also runs >> > in parallel,...). >> > >> > julia >> >> OK. Which lines are unneeded? >> >> Is it OK to remove all the comments, then just add "NPROC=1"? > > How about keeping "# No need to parallelize coccinelle in this case - this > mode takes only one file input."? Fair enough. I will send v4 shortly. > But if you think it is obvious, it would be ok to remove it also. Someone > can always do git blame and read the commit message if they have > questions. > > julia > -- > To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Best Regards Masahiro Yamada
On Tue, Nov 14, 2017 at 06:04:49PM +0900, Masahiro Yamada wrote: > diff --git a/scripts/coccicheck b/scripts/coccicheck > index 040a8b1..7da82a1 100755 > --- a/scripts/coccicheck > +++ b/scripts/coccicheck > @@ -70,6 +64,13 @@ if [ "$C" = "1" -o "$C" = "2" ]; then > # Take only the last argument, which is the C file to test > shift $(( $# - 1 )) > OPTIONS="$COCCIINCLUDE $1" > + > + # If -j option is given to Make, scripts/coccicheck runs in parallel. > + # If coccinelle also runs in parallel, it fails because multiple processes > + # try to get access to the same subdirectory that stores stdout/stderr. > + # No need to parallelize coccinelle in this case - this mode takes only > + # one file input. > + NPROC=1 Shouldn't this also warn to the user, and recommend to use a proper form to parallelize coccinelle? Otherwise a user might get the impression they are parallelizing coccinelle where they really did not. Luis > else > ONLINE=0 > if [ "$KBUILD_EXTMOD" = "" ] ; then
On Tue, 14 Nov 2017, Luis R. Rodriguez wrote: > On Tue, Nov 14, 2017 at 06:04:49PM +0900, Masahiro Yamada wrote: > > diff --git a/scripts/coccicheck b/scripts/coccicheck > > index 040a8b1..7da82a1 100755 > > --- a/scripts/coccicheck > > +++ b/scripts/coccicheck > > @@ -70,6 +64,13 @@ if [ "$C" = "1" -o "$C" = "2" ]; then > > # Take only the last argument, which is the C file to test > > shift $(( $# - 1 )) > > OPTIONS="$COCCIINCLUDE $1" > > + > > + # If -j option is given to Make, scripts/coccicheck runs in parallel. > > + # If coccinelle also runs in parallel, it fails because multiple processes > > + # try to get access to the same subdirectory that stores stdout/stderr. > > + # No need to parallelize coccinelle in this case - this mode takes only > > + # one file input. > > + NPROC=1 > > Shouldn't this also warn to the user, and recommend to use a proper form to > parallelize coccinelle? Otherwise a user might get the impression they are > parallelizing coccinelle where they really did not. Coccinelle sees a file at a time when using C=1 or C=2. There is nothing to parallelize at the Coccinelle level, if you want to use these options. julia > > Luis > > > else > > ONLINE=0 > > if [ "$KBUILD_EXTMOD" = "" ] ; then > _______________________________________________ > Cocci mailing list > Cocci@systeme.lip6.fr > https://systeme.lip6.fr/mailman/listinfo/cocci >
diff --git a/scripts/coccicheck b/scripts/coccicheck index 040a8b1..7da82a1 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="$J" -fi - FLAGS="--very-quiet" # You can use SPFLAGS to append extra arguments to coccicheck or override any @@ -70,6 +64,13 @@ if [ "$C" = "1" -o "$C" = "2" ]; then # Take only the last argument, which is the C file to test shift $(( $# - 1 )) OPTIONS="$COCCIINCLUDE $1" + + # If -j option is given to Make, scripts/coccicheck runs in parallel. + # If coccinelle also runs in parallel, it fails because multiple processes + # try to get access to the same subdirectory that stores stdout/stderr. + # No need to parallelize coccinelle in this case - this mode takes only + # one file input. + NPROC=1 else ONLINE=0 if [ "$KBUILD_EXTMOD" = "" ] ; then @@ -77,6 +78,12 @@ 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
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 sensible 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@socionext.com> --- 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 | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) -- 2.7.4