On Tue, Oct 2, 2018 at 1:18 PM Jacob Keller <jacob.keller@xxxxxxxxx> wrote:
>
> On Tue, Oct 2, 2018 at 1:07 PM Jacob Keller <jacob.e.keller@xxxxxxxxx> wrote:
> >
> > From: Jacob Keller <jacob.keller@xxxxxxxxx>
> >
> > make coccicheck is used in order to apply coccinelle semantic patches,
> > and see if any of the transformations found within contrib/coccinelle/
> > can be applied to the current code base.
> >
> > Pass every file to a single invocation of spatch, instead of running
> > spatch once per source file.
> >
> > This reduces the time required to run make coccicheck by a significant
> > amount of time:
> >
> > Prior timing of make coccicheck
> > real 6m14.090s
> > user 25m2.606s
> > sys 1m22.919s
> >
> > New timing of make coccicheck
> > real 1m36.580s
> > user 7m55.933s
> > sys 0m18.219s
> >
> > This is nearly a 4x decrease in the time required to run make
> > coccicheck. This is due to the overhead of restarting spatch for every
> > file. By processing all files at once, we can amortize this startup cost
> > across the total number of files, rather than paying it once per file.
> >
> > Signed-off-by: Jacob Keller <jacob.keller@xxxxxxxxx>
> > ---
>
> Forgot to add what changed. I dropped the subshell and "||" bit around
> invoking spatch.
>
> Thanks,
> Jake
>
Junio, do you want me to update the commit message on my side with the
memory concerns? Or could you update it to mention memory as a noted
trade off.
Thanks,
Jake
>
> > Makefile | 6 ++----
> > 1 file changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/Makefile b/Makefile
> > index df1df9db78da..da692ece9e12 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -2715,10 +2715,8 @@ endif
> > %.cocci.patch: %.cocci $(COCCI_SOURCES)
> > @echo ' ' SPATCH $<; \
> > ret=0; \
> > - for f in $(COCCI_SOURCES); do \
> > - $(SPATCH) --sp-file $< $$f $(SPATCH_FLAGS) || \
> > - { ret=$$?; break; }; \
> > - done >$@+ 2>$@.log; \
> > + $(SPATCH) --sp-file $< $(COCCI_SOURCES) $(SPATCH_FLAGS) >$@+ 2>$@.log; \
> > + ret=$$?; \
> > if test $$ret != 0; \
> > then \
> > cat $@.log; \
> > --
> > 2.18.0.219.gaf81d287a9da
> >
