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Date: Fri, 16 May 2014 14:43:15 -0700
From: Andi Kleen <andi@...stfloor.org>
To: linux-kernel@...r.kernel.org
Cc: akpm@...ux-foundation.org, Andi Kleen <ak@...ux.intel.com>,
linux-kbuild@...r.kernel.org, mmarek@...e.cz
Subject: [PATCH 8/8] Kbuild: add inline-account tool to find inline bloat
From: Andi Kleen <ak@...ux.intel.com>
Add a tool to hunt for inline bloat. It uses objdump -S to account
inlines.
Example output:
Total code bytes seen 10463206
Code bytes by functions:
Function Total Avg Num
kmalloc 37132 (0.00%) 11 3310
ixgbe_read_reg 35440 (0.00%) 24 1444
spin_lock 28975 (0.00%) 11 2575
constant_test_bit 26387 (0.00%) 5 4642
arch_spin_unlock 24986 (0.00%) 7 3364
spin_unlock_irqrestore 24928 (0.00%) 11 2258
readl 24584 (0.00%) 4 5344
writel 23199 (0.00%) 6 3643
perf_fetch_caller_regs 22436 (0.00%) 27 821
get_current 22076 (0.00%) 9 2288
_radeon_msleep 19680 (0.00%) 55 353
INIT_LIST_HEAD 19410 (0.00%) 11 1747
list_del 19270 (0.00%) 16 1176
__ew32_prepare 19080 (0.00%) 25 740
__list_add 17830 (0.00%) 12 1406
Cc: linux-kbuild@...r.kernel.org
Cc: mmarek@...e.cz
Signed-off-by: Andi Kleen <ak@...ux.intel.com>
---
scripts/inline-account.py | 164 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 164 insertions(+)
create mode 100755 scripts/inline-account.py
diff --git a/scripts/inline-account.py b/scripts/inline-account.py
new file mode 100755
index 0000000..2dfbf7c
--- /dev/null
+++ b/scripts/inline-account.py
@@ -0,0 +1,164 @@
+#!/usr/bin/python
+# account code bytes per source code / functions from objdump -Sl output
+# useful to find inline bloat
+# Author: Andi Kleen
+import os, sys, re, argparse, multiprocessing
+from collections import Counter
+
+p = argparse.ArgumentParser(
+ description="""
+Account code bytes per source code / functions from objdump.
+Useful to find inline bloat.
+
+The line numbers are the beginning of a block, so the actual code can be later.
+Line numbers can be a also little off due to objdump bugs
+also some misaccounting can happen due to inexact gcc debug information.
+The number output for functions may account a single large function multiple
+times. program/object files need to be built with -g.
+
+This is somewhat slow due to objdump -S being slow. It helps to have
+plenty of cores.""")
+p.add_argument('--min-bytes', type=int, help='minimum bytes to report', default=100)
+p.add_argument('--threads', '-t', type=int, default=multiprocessing.cpu_count(),
+ help='Number of objdump processes to run')
+p.add_argument('file', help='object file/program as input')
+args = p.parse_args()
+
+def get_syms(fn):
+ f = os.popen("nm --print-size " + fn)
+ syms = []
+ pc = None
+ for l in f:
+ n = l.split()
+ if len(n) > 2 and n[2].upper() == "T":
+ pc = int(n[0], 16)
+ syms.append(pc)
+ ln = int(n[1], 16)
+ f.close()
+ if not pc:
+ sys.exit(fn + " has no symbols")
+ syms.append(pc + ln)
+ return syms
+
+class Account:
+ pass
+
+def add_account(a, b):
+ a.funcbytes += b.funcbytes
+ a.linebytes += b.linebytes
+ a.funccount += b.funccount
+ a.nolinebytes += a.nolinebytes
+ a.nofuncbytes += a.nofuncbytes
+ a.total += b.total
+ return a
+
+# dont add sys.exit here, causes deadlocks
+def account_range(r):
+ a = Account()
+ a.funcbytes = Counter()
+ a.linebytes = Counter()
+ a.funccount = Counter()
+ a.nolinebytes = 0
+ a.nofuncbytes = 0
+ a.total = 0
+
+ line = None
+ func = None
+ codefunc = None
+
+ cmd = ("objdump -Sl %s --start-address=%#x --stop-address=%#x" %
+ (args.file, r[0], r[1]))
+ f = os.popen(cmd)
+ for l in f:
+ # 250: e8 00 00 00 00 callq 255 <proc_skip_spaces+0x5>
+ m = re.match(r'\s*([0-9a-fA-F]+):\s+(.*)', l)
+ if m:
+ #print "iscode", func, l,
+ bytes = len(re.findall(r'[0-9a-f][0-9a-f] ', m.group(2)))
+ if not func:
+ a.nofuncbytes += bytes
+ continue
+ if not line:
+ a.nolinebytes += bytes
+ continue
+ a.total += bytes
+ a.funcbytes[func] += bytes
+ a.linebytes[(file, line)] += bytes
+ codefunc = func
+ continue
+
+ # sysctl_init():
+ m = re.match(r'([a-zA-Z_][a-zA-Z0-9_]*)\(\):$', l)
+ if m:
+ if codefunc and m.group(1) != codefunc:
+ a.funccount[codefunc] += 1
+ codefunc = None
+ func = m.group(1)
+ continue
+
+ # /sysctl.c:1666
+ m = re.match(r'^([^:]+):(\d+)$', l)
+ if m:
+ file, line = m.group(1), int(m.group(2))
+ continue
+ f.close()
+
+ if codefunc:
+ a.funccount[codefunc] += 1
+ return a
+
+# objdump -S is slow, so we parallelize
+
+# split symbol table into chunks for parallelization
+# we split on functions boundaries to avoid mis-accounting
+# assumes functions have roughly similar length
+syms = sorted(get_syms(args.file))
+chunk = min((len(syms) - 1) / args.threads, len(syms) - 1)
+boundaries = [syms[x] for x in range(0, len(syms) - 1, chunk)] + [syms[-1]]
+ranges = [(boundaries[x], boundaries[x+1]) for x in range(0, len(boundaries) - 1)]
+assert ranges[0][0] == syms[0]
+assert ranges[-1][1] == syms[-1]
+
+# map-reduce
+if args.threads == 1:
+ al = map(account_range, ranges)
+else:
+ al = multiprocessing.Pool(args.threads).map(account_range, ranges)
+a = reduce(add_account, al)
+
+print "Total code bytes seen", a.total
+#print "Bytes with no function %d (%.2f%%)" % (a.nofuncbytes, 100.0*(float(a.nofuncbytes)/a.total))
+#print "Bytes with no lines %d (%.2f%%)" % (a.nolinebytes, 100.0*(float(a.nolinebytes)/a.total))
+
+def sort_map(m):
+ return sorted(m.keys(), key=lambda x: m[x], reverse=True)
+
+print "\nCode bytes by functions:"
+print "%-50s %-5s %-5s %-5s %-5s" % ("Function", "Total", "", "Avg", "Num")
+for j in sort_map(a.funcbytes):
+ if a.funcbytes[j] < args.min_bytes:
+ break
+ print "%-50s %-5d (%.2f%%) %-5d %-5d" % (
+ j,
+ a.funcbytes[j],
+ a.funcbytes[j] / float(a.total),
+ a.funcbytes[j] / a.funccount[j],
+ a.funccount[j])
+
+for j in a.linebytes.keys():
+ if a.linebytes[j] < args.min_bytes:
+ del a.linebytes[j]
+
+# os.path.commonprefix fails with >50k entries
+# just use the first 10
+prefix = os.path.commonprefix(map(lambda x: x[0], a.linebytes.keys()[:10]))
+
+print "\nCode bytes by nearby source line blocks:"
+print "prefix", prefix
+
+print "%-50s %-5s" % ("Line", "Total")
+for j in sort_map(a.linebytes):
+ print "%-50s %-5d (%.2f%%)" % (
+ "%s:%d" % (j[0].replace(prefix, ""), j[1]),
+ a.linebytes[j],
+ a.linebytes[j] / float(a.total))
--
1.9.0
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