[PATCH 1/2] scripts/bloat-o-meter: don't use readlines()

From: Alexey Dobriyan
Date: Fri Nov 18 2016 - 17:42:03 EST


readlines() conses whole list before doing anything which is slower
for big object files. Use per line iterator.

Speed up is ~2% on "allyesconfig" type of kernel.

$ perf stat -r 16 taskset -c 15 ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux >/dev/null
...
Before: 7.247708646 seconds time elapsed ( +- 0.28% )
After: 7.091202853 seconds time elapsed ( +- 0.15% )


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

scripts/bloat-o-meter | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)

--- a/scripts/bloat-o-meter
+++ b/scripts/bloat-o-meter
@@ -18,17 +18,18 @@ if len(sys.argv) != 3:

def getsizes(file):
sym = {}
- for l in os.popen("nm --size-sort " + file).readlines():
- size, type, name = l[:-1].split()
- if type in "tTdDbBrR":
- # strip generated symbols
- if name.startswith("__mod_"): continue
- if name.startswith("SyS_"): continue
- 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)
- sym[name] = sym.get(name, 0) + int(size, 16)
+ with os.popen("nm --size-sort " + file) as f:
+ for line in f:
+ size, type, name = line.split()
+ if type in "tTdDbBrR":
+ # strip generated symbols
+ if name.startswith("__mod_"): continue
+ if name.startswith("SyS_"): continue
+ 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)
+ sym[name] = sym.get(name, 0) + int(size, 16)
return sym

old = getsizes(sys.argv[1])