Commit 87ecb582 authored Mar 16, 2020 by Peter Zijlstra Committed by Ingo Molnar Apr 22, 2020

objtool: Use sec_offset_hash() for insn_hash



In preparation for find_insn_containing(), change insn_hash to use
sec_offset_hash().

This actually reduces runtime; probably because mixing in the section
index reduces the collisions due to text sections all starting their
instructions at offset 0.

Runtime on vmlinux.o from 3.1 to 2.5 seconds.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200416115119.227240432@infradead.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 34f7c96d

tools/objtool/check.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -34,9 +34,10 @@ struct instruction find_insn(struct objtool_file file,
		{
		struct instruction *insn;

		hash_for_each_possible(file->insn_hash, insn, hash, offset)
		hash_for_each_possible(file->insn_hash, insn, hash, sec_offset_hash(sec, offset)) {
		if (insn->sec == sec && insn->offset == offset)
		return insn;
		}

		return NULL;
		}
		@@ -282,7 +283,7 @@ static int decode_instructions(struct objtool_file *file)
		if (ret)
		goto err;

		hash_add(file->insn_hash, &insn->hash, insn->offset);
		hash_add(file->insn_hash, &insn->hash, sec_offset_hash(sec, insn->offset));
		list_add_tail(&insn->list, &file->insn_list);
		nr_insns++;
		}

Admin message