| Message ID | 20200812173958.2307251-2-masahiroy@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kbuild: clang-tidy | expand |
On Wed, Aug 12, 2020 at 10:40 AM Masahiro Yamada <masahiroy@kernel.org> wrote: > > After the allmodconfig build, this script takes about 5 sec on my > machine. Most of the run-time is consumed for needless regex matching. > > We know the format of .*.cmd file; the first line is the build command. > There is no need to parse the remaining. > > With this optimization, now it runs in about 1 sec with the allmodconfig > build. > > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Before your patch, my x86_64 allmodconfig: $ /usr/bin/time -v ./scripts/gen_compile_commands.py ... Elapsed (wall clock) time (h:mm:ss or m:ss): 0:08.35 ... After: Elapsed (wall clock) time (h:mm:ss or m:ss): 0:02.10 So it's a nice speedup. Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> small nit below: > --- > > scripts/gen_compile_commands.py | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py > index c458696ef3a7..19c7338740e7 100755 > --- a/scripts/gen_compile_commands.py > +++ b/scripts/gen_compile_commands.py > @@ -125,11 +125,9 @@ def main(): > filepath = os.path.join(dirpath, filename) > > with open(filepath, 'rt') as f: > - for line in f: > - result = line_matcher.match(line) > - if not result: > - continue > - > + line = f.readline() > + result = line_matcher.match(line) If `line` is not referenced beyond the following statement, consider combining the two statement into one: result = line_matcher.match(f.readline()) > + if result: > try: > entry = process_line(directory, dirpath, > result.group(1), result.group(2)) > -- > 2.25.1 >
diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py index c458696ef3a7..19c7338740e7 100755 --- a/scripts/gen_compile_commands.py +++ b/scripts/gen_compile_commands.py @@ -125,11 +125,9 @@ def main(): filepath = os.path.join(dirpath, filename) with open(filepath, 'rt') as f: - for line in f: - result = line_matcher.match(line) - if not result: - continue - + line = f.readline() + result = line_matcher.match(line) + if result: try: entry = process_line(directory, dirpath, result.group(1), result.group(2))
After the allmodconfig build, this script takes about 5 sec on my machine. Most of the run-time is consumed for needless regex matching. We know the format of .*.cmd file; the first line is the build command. There is no need to parse the remaining. With this optimization, now it runs in about 1 sec with the allmodconfig build. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> --- scripts/gen_compile_commands.py | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)