dwarf_loader: Permit a flexible HASHTAGS__BITS
Currently, types/tags hash table has fixed HASHTAGS__BITS = 15.
That means the number of buckets will be 1UL << 15 = 32768.
In my experiments, a thin-LTO built vmlinux has roughly 9M entries
in types table and 5.2M entries in tags table. So the number
of buckets is too less for an efficient lookup. This patch
refactored the code to allow the number of buckets to be changed.
In addition, currently hashtags__fn(key) return value is
assigned to uint16_t. Change to uint32_t as in a later patch
the number of hashtag bits can be increased to be more than 16.
Committer notes:
Since we keep a pointer to the 'struct dwarf_cu' in cu->priv and now we
want to release the hashtables it contains, we need to make it also be
dynamicly allocated, otherwise tools such as 'codiff' will fail when
calling cus__delete() -> cu__delete() -> dwarf_cu__delelete().
Signed-off-by: Yonghong Song <yhs@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Bill Wendling <morbo@google.com>
Cc: bpf@vger.kernel.org
Cc: dwarves@vger.kernel.org
Cc: kernel-team@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
1 file changed
