mirror of
https://github.com/morgan9e/systemd
synced 2026-04-14 00:14:32 +09:00
c09ce222b6
Passing in the func, file and line information complicates the interface. On top of that, it prevents forward declaring Hashmap in strv.h, as we need to pass the macros everywhere that we allocate a hashmap, which means we have to include the hashmap header everywhere we have a function that allocates a hashmap instead of just having to forward declare Hashmap. Let's drop the file, func and line information from the debug information. Instead, in the future we can add a description field to hashmaps like we already have in various other structs to describe the purpose of the hashmap which should be much more useful than having the file, line and function where the hashmap was allocated.
79 lines
3.4 KiB
Python
79 lines
3.4 KiB
Python
#!/usr/bin/env python3
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# SPDX-License-Identifier: LGPL-2.1-or-later
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# pylint: disable=consider-using-f-string
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import gdb
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class sd_dump_hashmaps(gdb.Command):
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"dump systemd's hashmaps"
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def __init__(self):
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super().__init__("sd_dump_hashmaps", gdb.COMMAND_DATA, gdb.COMPLETE_NONE)
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def invoke(self, arg, _from_tty):
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d = gdb.parse_and_eval("hashmap_debug_list")
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hashmap_type_info = gdb.parse_and_eval("hashmap_type_info")
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uchar_t = gdb.lookup_type("unsigned char")
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ulong_t = gdb.lookup_type("unsigned long")
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debug_offset = gdb.parse_and_eval("(unsigned long)&((HashmapBase*)0)->debug")
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print("type, hash, indirect, entries, max_entries, buckets, creator")
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while d:
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h = gdb.parse_and_eval(f"(HashmapBase*)((char*){int(d.cast(ulong_t))} - {debug_offset})")
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if h["has_indirect"]:
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storage_ptr = h["indirect"]["storage"].cast(uchar_t.pointer())
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n_entries = h["indirect"]["n_entries"]
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n_buckets = h["indirect"]["n_buckets"]
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else:
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storage_ptr = h["direct"]["storage"].cast(uchar_t.pointer())
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n_entries = h["n_direct_entries"]
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n_buckets = hashmap_type_info[h["type"]]["n_direct_buckets"]
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t = ["plain", "ordered", "set"][int(h["type"])]
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print(f'{t}, {h["hash_ops"]}, {bool(h["has_indirect"])}, {n_entries}, {d["max_entries"]}, {n_buckets}')
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if arg != "" and n_entries > 0:
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dib_raw_addr = storage_ptr + hashmap_type_info[h["type"]]["entry_size"] * n_buckets
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histogram = {}
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for i in range(0, n_buckets):
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dib = int(dib_raw_addr[i])
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histogram[dib] = histogram.get(dib, 0) + 1
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for dib in sorted(histogram):
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if dib != 255:
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print(f"{dib:>3} {histogram[dib]:>8} {float(histogram[dib]/n_entries):.0%} of entries")
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else:
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print(f"{dib:>3} {histogram[dib]:>8} {float(histogram[dib]/n_buckets):.0%} of slots")
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s = sum(dib*count for (dib, count) in histogram.items() if dib != 255) / n_entries
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print(f"mean DIB of entries: {s}")
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blocks = []
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current_len = 1
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prev = int(dib_raw_addr[0])
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for i in range(1, n_buckets):
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dib = int(dib_raw_addr[i])
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if (dib == 255) != (prev == 255):
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if prev != 255:
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blocks += [[i, current_len]]
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current_len = 1
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else:
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current_len += 1
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prev = dib
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if prev != 255:
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blocks += [[i, current_len]]
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# a block may be wrapped around
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if len(blocks) > 1 and blocks[0][0] == blocks[0][1] and blocks[-1][0] == n_buckets - 1:
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blocks[0][1] += blocks[-1][1]
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blocks = blocks[0:-1]
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print("max block: {}".format(max(blocks, key=lambda a: a[1])))
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print("sum block lens: {}".format(sum(b[1] for b in blocks)))
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print("mean block len: {}".format(sum(b[1] for b in blocks) / len(blocks)))
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d = d["debug_list_next"]
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sd_dump_hashmaps()
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