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authorMichal Schmidt <mschmidt@redhat.com>2014-10-15 01:31:23 +0200
committerMichal Schmidt <mschmidt@redhat.com>2014-10-30 19:50:51 +0100
commit2ea8c08306c7e33f8217a878cf990fc491c9432c (patch)
tree51a9f73447006595887a5bb5f0ef0091551b59de /tools/gdb-sd_dump_hashmaps.py
parent89439d4fc0d29f04ac68432fd06ab84bc4e36e20 (diff)
tools: add gdb command to dump hashmap information
$ sudo gdb -p 1 ... (gdb) source gdb-sd_dump_hashmaps.py (gdb) sd_dump_hashmaps ... lists allocated hashmaps ... (gdb) sd_dump_hashmaps 1 ... lists allocated hashmaps, their DIB histograms and contiguous blocks statistics ...
Diffstat (limited to 'tools/gdb-sd_dump_hashmaps.py')
-rw-r--r--tools/gdb-sd_dump_hashmaps.py94
1 files changed, 94 insertions, 0 deletions
diff --git a/tools/gdb-sd_dump_hashmaps.py b/tools/gdb-sd_dump_hashmaps.py
new file mode 100644
index 0000000000..9ee81fb05a
--- /dev/null
+++ b/tools/gdb-sd_dump_hashmaps.py
@@ -0,0 +1,94 @@
+# -*- Mode: python; coding: utf-8; indent-tabs-mode: nil -*- */
+#
+# This file is part of systemd.
+#
+# Copyright 2014 Michal Schmidt
+#
+# systemd is free software; you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation; either version 2.1 of the License, or
+# (at your option) any later version.
+#
+# systemd is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with systemd; If not, see <http://www.gnu.org/licenses/>.
+
+import gdb
+
+class sd_dump_hashmaps(gdb.Command):
+ "dump systemd's hashmaps"
+
+ def __init__(self):
+ super(sd_dump_hashmaps, self).__init__("sd_dump_hashmaps", gdb.COMMAND_DATA, gdb.COMPLETE_NONE)
+
+ def invoke(self, arg, from_tty):
+ d = gdb.parse_and_eval("hashmap_debug_list")
+ all_entry_sizes = gdb.parse_and_eval("all_entry_sizes")
+ all_direct_buckets = gdb.parse_and_eval("all_direct_buckets")
+ hashmap_base_t = gdb.lookup_type("HashmapBase")
+ uchar_t = gdb.lookup_type("unsigned char")
+ ulong_t = gdb.lookup_type("unsigned long")
+ debug_offset = gdb.parse_and_eval("(unsigned long)&((HashmapBase*)0)->debug")
+
+ print "type, hash, indirect, entries, max_entries, buckets, creator"
+ while d:
+ h = gdb.parse_and_eval("(HashmapBase*)((char*)%d - %d)" % (int(d.cast(ulong_t)), debug_offset))
+
+ if h["has_indirect"]:
+ storage_ptr = h["indirect"]["storage"].cast(uchar_t.pointer())
+ n_entries = h["indirect"]["n_entries"]
+ n_buckets = h["indirect"]["n_buckets"]
+ else:
+ storage_ptr = h["direct"]["storage"].cast(uchar_t.pointer())
+ n_entries = h["n_direct_entries"]
+ n_buckets = all_direct_buckets[int(h["type"])];
+
+ t = ["plain", "ordered", "set"][int(h["type"])]
+
+ print "%s, %s, %s, %d, %d, %d, %s (%s:%d)" % (t, h["hash_ops"], bool(h["has_indirect"]), n_entries, d["max_entries"], n_buckets, d["func"], d["file"], d["line"])
+
+ if arg != "" and n_entries > 0:
+ dib_raw_addr = storage_ptr + (all_entry_sizes[h["type"]] * n_buckets)
+
+ histogram = {}
+ for i in xrange(0, n_buckets):
+ dib = int(dib_raw_addr[i])
+ histogram[dib] = histogram.get(dib, 0) + 1
+
+ for dib in sorted(iter(histogram)):
+ if dib != 255:
+ print "%3d %8d %f%% of entries" % (dib, histogram[dib], 100.0*histogram[dib]/n_entries)
+ else:
+ print "%3d %8d %f%% of slots" % (dib, histogram[dib], 100.0*histogram[dib]/n_buckets)
+ print "mean DIB of entries: %f" % (sum([dib*histogram[dib] for dib in iter(histogram) if dib != 255])*1.0/n_entries)
+
+ blocks = []
+ current_len = 1
+ prev = int(dib_raw_addr[0])
+ for i in xrange(1, n_buckets):
+ dib = int(dib_raw_addr[i])
+ if (dib == 255) != (prev == 255):
+ if prev != 255:
+ blocks += [[i, current_len]]
+ current_len = 1
+ else:
+ current_len += 1
+
+ prev = dib
+ if prev != 255:
+ blocks += [[i, current_len]]
+ # a block may be wrapped around
+ if len(blocks) > 1 and blocks[0][0] == blocks[0][1] and blocks[-1][0] == n_buckets - 1:
+ blocks[0][1] += blocks[-1][1]
+ blocks = blocks[0:-1]
+ print "max block: %s" % max(blocks, key=lambda a: a[1])
+ print "sum block lens: %d" % sum(b[1] for b in blocks)
+ print "mean block len: %f" % (1.0 * sum(b[1] for b in blocks) / len(blocks))
+
+ d = d["debug_list_next"]
+
+sd_dump_hashmaps()