[PATCH 2/2] scripts: add kmemleak2pprof.py for slab usage analysis
From: Vincent Whitchurch
Date: Tue Aug 28 2018 - 06:39:25 EST
Add a script which converts /sys/kernel/debug/kmemleak_all to the pprof
format, which can be used for analysing memory usage. See
https://github.com/google/pprof.
$ ./kmemleak2pprof.py kmemleak_all
$ pprof -text -ignore free_area_init_node -compact_labels -nodecount 10 prof
Showing nodes accounting for 4.85MB, 34.05% of 14.23MB total
Dropped 3989 nodes (cum <= 0.07MB)
Showing top 10 nodes out of 190
flat flat% sum% cum cum%
1.39MB 9.78% 9.78% 1.61MB 11.29% new_inode_pseudo+0x8/0x4c
0.75MB 5.27% 15.04% 0.75MB 5.27% alloc_large_system_hash+0x19c/0x2b8
0.73MB 5.12% 20.17% 0.86MB 6.07% kernfs_new_node+0x30/0x50
0.66MB 4.62% 24.79% 0.66MB 4.62% __vmalloc_node.constprop.9+0x48/0x50
0.61MB 4.28% 29.06% 0.61MB 4.28% d_alloc+0x10/0x78
0.22MB 1.52% 30.58% 0.22MB 1.52% alloc_inode+0x1c/0xa4
0.18MB 1.28% 31.86% 0.20MB 1.42% _do_fork+0xb0/0x41c
0.13MB 0.88% 32.74% 0.13MB 0.88% early_trace_init+0x16c/0x374
0.09MB 0.66% 33.40% 0.17MB 1.17% inet_init+0x128/0x24c
0.09MB 0.65% 34.05% 0.09MB 0.65% __kernfs_new_node+0x34/0x1a8
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx>
---
scripts/kmemleak2pprof.py | 164 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 164 insertions(+)
create mode 100755 scripts/kmemleak2pprof.py
diff --git a/scripts/kmemleak2pprof.py b/scripts/kmemleak2pprof.py
new file mode 100755
index 000000000000..1295d3ca9a9d
--- /dev/null
+++ b/scripts/kmemleak2pprof.py
@@ -0,0 +1,164 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2018 Axis Communications AB
+#
+# Converts /sys/kernel/debug/kmemleak_all to the pprof format, see
+# https://github.com/google/pprof.
+#
+# profile_pb2.py can be generated with the following commands. protoc is
+# packaged as protobuf-compiler in Debian:
+#
+# wget https://raw.githubusercontent.com/google/pprof/master/proto/profile.proto
+# protoc -I. --python_out=. profile.proto
+
+import argparse
+
+from collections import defaultdict
+
+import profile_pb2
+
+
+# object 0xee0243b0 (size 464):
+# comm "swapper/0", pid 0, jiffies 4294937296
+# [<80220673>] alloc_inode+0x13/0x60
+# [<80221cc5>] new_inode_pseudo+0xd/0x38
+# [<802568a3>] proc_setup_thread_self+0x37/0xc4
+# [<8020e8c1>] mount_ns+0x55/0x94
+# [<8024f2e1>] proc_mount+0x45/0x48
+# [<8020ee9b>] mount_fs+0x1f/0x104
+# [<80224785>] vfs_kern_mount.part.3+0x35/0xbc
+# [<80224833>] kern_mount_data+0x17/0x2c
+# [<8024f44b>] pid_ns_prepare_proc+0x13/0x24
+# [<8012ed0d>] alloc_pid+0x309/0x338
+# [<80118e2b>] copy_process.part.5+0xa2b/0x1308
+# [<80119807>] _do_fork+0x77/0x2f0
+# [<80119abf>] kernel_thread+0x23/0x28
+# [<8053517f>] rest_init+0x27/0xb4
+# [<80900afb>] start_kernel+0x369/0x372
+# [<0000807b>] 0x807b
+class KmemleakAll(object):
+ def __init__(self):
+ pass
+
+ def analyze(self, f):
+ allocs = defaultdict(int)
+ stack = []
+ size = 0
+
+ while True:
+ line = f.readline()
+ if not line:
+ break
+
+ line = line.strip()
+
+ if line.startswith('['):
+ # (null) is in the address part so later parsing steps fail.
+ # Don't bother fixing it up since it's clearly bogus.
+ if '(null)' in line:
+ continue
+
+ stack.append(line)
+ continue
+ elif line.startswith('comm'):
+ continue
+
+ if size:
+ allocs[(tuple(stack), size)] += 1
+ size = 0
+
+ stack = []
+ size = int(line.split('(size ')[1].strip('):'))
+
+ return sorted(allocs.items(), key=lambda x: x[0][1] * x[1], reverse=True)
+
+
+class ProfileWriter(object):
+ def __init__(self, allocs):
+ self.profile = profile_pb2.Profile()
+ self.strings = ['']
+ self.allocs = allocs
+ self.locations = {}
+ self.functions = {}
+
+ def stridx(self, s):
+ try:
+ idx = self.strings.index(s)
+ except ValueError:
+ idx = len(self.strings)
+ self.strings.append(s)
+
+ return idx
+
+ def get_function_id(self, funcname, filename):
+ try:
+ return self.functions[(funcname, filename)].id
+ except KeyError:
+ pass
+
+ function = self.profile.function.add()
+ function.id = len(self.functions) + 1
+ function.name = self.stridx(funcname)
+ function.filename = self.stridx(filename)
+
+ self.functions[(funcname, filename)] = function
+
+ return function.id
+
+ def get_location_id(self, addr):
+ if addr.startswith('['):
+ _, func = addr.split(' ', maxsplit=1)
+
+ try:
+ return self.locations[addr].id
+ except KeyError:
+ pass
+
+ location = self.profile.location.add()
+ location.id = len(self.locations) + 1
+
+ # We don't have access to the file or line information.
+ locline = location.line.add()
+ locline.function_id = self.get_function_id(func, 'dummy.c')
+
+ self.locations[addr] = location
+
+ return location.id
+
+ def write(self, fn):
+ valuetype = self.profile.sample_type.add()
+ valuetype.type = self.stridx('slab')
+ valuetype.unit = self.stridx('bytes')
+
+ for i, alloc in enumerate(self.allocs):
+ stacksize, count = alloc
+ stack, size = stacksize
+
+ for instance in range(count):
+ sample = self.profile.sample.add()
+ sample.value.append(size)
+
+ for addr in stack:
+ sample.location_id.append(self.get_location_id(addr))
+
+ self.profile.string_table.extend(self.strings)
+
+ with open(fn, 'wb') as f:
+ f.write(self.profile.SerializeToString())
+
+
+def main():
+ parser = argparse.ArgumentParser()
+ parser.add_argument('--output', default='prof')
+ parser.add_argument('data')
+ args = parser.parse_args()
+
+ with open(args.data) as f:
+ allocs = KmemleakAll().analyze(f)
+
+ ProfileWriter(allocs).write(args.output)
+
+
+if __name__ == '__main__':
+ main()
--
2.11.0