From 2ea8c08306c7e33f8217a878cf990fc491c9432c Mon Sep 17 00:00:00 2001 From: Michal Schmidt Date: Wed, 15 Oct 2014 01:31:23 +0200 Subject: [PATCH] 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 ... --- Makefile.am | 3 ++ tools/gdb-sd_dump_hashmaps.py | 94 +++++++++++++++++++++++++++++++++++ 2 files changed, 97 insertions(+) create mode 100644 tools/gdb-sd_dump_hashmaps.py diff --git a/Makefile.am b/Makefile.am index 946e46f2d..3b273d492 100644 --- a/Makefile.am +++ b/Makefile.am @@ -6247,3 +6247,6 @@ print-%: git-contrib: @git shortlog -s `git describe --abbrev=0`.. | cut -c8- | awk '{ print $$0 "," }' | sort -u + +EXTRA_DIST += \ + tools/gdb-sd_dump_hashmaps.py diff --git a/tools/gdb-sd_dump_hashmaps.py b/tools/gdb-sd_dump_hashmaps.py new file mode 100644 index 000000000..9ee81fb05 --- /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 . + +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() -- 2.30.2