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
> 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
>
