[PATCH 2/2] scripts/bloat-o-meter: compile .NUMBER regex

From: Alexey Dobriyan
Date: Fri Nov 18 2016 - 17:44:33 EST


Every often used regex is better be compiled in Python.

Speedup is about ~9.8% (whee!)

$ perf stat -r 16 taskset -c 15 ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux >/dev/null
7.091202853 seconds time elapsed ( +- 0.15% )

+re.compile
6.397564973 seconds time elapsed ( +- 0.34% )

Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---

scripts/bloat-o-meter | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/scripts/bloat-o-meter
+++ b/scripts/bloat-o-meter
@@ -16,6 +16,8 @@ if len(sys.argv) != 3:
sys.stderr.write("usage: %s file1 file2\n" % sys.argv[0])
sys.exit(-1)

+re_NUMBER = re.compile(r'\.[0-9]+')
+
def getsizes(file):
sym = {}
with os.popen("nm --size-sort " + file) as f:
@@ -28,7 +30,7 @@ def getsizes(file):
if name.startswith("compat_SyS_"): continue
if name == "linux_banner": continue
# statics and some other optimizations adds random .NUMBER
- name = re.sub(r'\.[0-9]+', '', name)
+ name = re_NUMBER.sub('', name)
sym[name] = sym.get(name, 0) + int(size, 16)
return sym