diff options
author | Josh Stone <jistone@redhat.com> | 2009-08-28 18:01:51 -0700 |
---|---|---|
committer | Josh Stone <jistone@redhat.com> | 2009-08-28 18:47:34 -0700 |
commit | 8d7a7bd9456c6067e874dabf6ee08b0a4e0de7d0 (patch) | |
tree | 0aef83c1f1a789d938a4583a84fa0e9c050b0c1c /dwflpp.cxx | |
parent | 3a45db133bc306fdbdb2b0c8f3aa7f15f1890d9e (diff) | |
download | systemtap-steved-8d7a7bd9456c6067e874dabf6ee08b0a4e0de7d0.tar.gz systemtap-steved-8d7a7bd9456c6067e874dabf6ee08b0a4e0de7d0.tar.xz systemtap-steved-8d7a7bd9456c6067e874dabf6ee08b0a4e0de7d0.zip |
Cache inline instance lookups
We used to call dwarf_func_inline_instances to get the locations where
inlines are used. This function has to iterate through nearly all DIEs
to find instances, which is a lot of redundant work when we're probing
multiple inline functions.
Now we have our own dwarf iterator to cache all inline instances back to
their origin. This only needs to be called once for each CU, and all
further inlines are just a map lookup. Some quick benchmarks:
stap -l Before After
kernel.function("*") 25010ms 2110ms
module("*").function("*") 86550ms 16920ms
process("stap").function("*") 41330ms 580ms
* dwflpp.cxx (dwflpp::cu_inl_function_caching_callback): Removed.
(dwflpp::cache_inline_instances): New caching iterator.
(dwflpp::iterate_over_inline_instances): Cache each CU once.
Diffstat (limited to 'dwflpp.cxx')
-rw-r--r-- | dwflpp.cxx | 61 |
1 files changed, 50 insertions, 11 deletions
@@ -502,12 +502,52 @@ dwflpp::func_is_inline() } -int -dwflpp::cu_inl_function_caching_callback (Dwarf_Die* func, void *arg) +void +dwflpp::cache_inline_instances (Dwarf_Die* die) { - vector<Dwarf_Die>* v = static_cast<vector<Dwarf_Die>*>(arg); - v->push_back (* func); - return DWARF_CB_OK; + // If this is an inline instance, link it back to its origin + Dwarf_Die origin; + if (dwarf_tag(die) == DW_TAG_inlined_subroutine && + dwarf_attr_die(die, DW_AT_abstract_origin, &origin)) + { + vector<Dwarf_Die>*& v = cu_inl_function_cache[origin.addr]; + if (!v) + v = new vector<Dwarf_Die>; + v->push_back(*die); + } + + // Recurse through other scopes that may contain inlines + Dwarf_Die child, import; + if (dwarf_child(die, &child) == 0) + do + { + switch (dwarf_tag (&child)) + { + // tags that could contain inlines + case DW_TAG_compile_unit: + case DW_TAG_module: + case DW_TAG_lexical_block: + case DW_TAG_with_stmt: + case DW_TAG_catch_block: + case DW_TAG_try_block: + case DW_TAG_entry_point: + case DW_TAG_inlined_subroutine: + case DW_TAG_subprogram: + cache_inline_instances(&child); + break; + + // imported dies should be followed + case DW_TAG_imported_unit: + if (dwarf_attr_die(&child, DW_AT_import, &import)) + cache_inline_instances(&import); + break; + + // nothing to do for other tags + default: + break; + } + } + while (dwarf_siblingof(&child, &child) == 0); } @@ -518,13 +558,12 @@ dwflpp::iterate_over_inline_instances (int (* callback)(Dwarf_Die * die, void * assert (function); assert (func_is_inline ()); + if (cu_inl_function_cache_done.insert(cu->addr).second) + cache_inline_instances(cu); + vector<Dwarf_Die>* v = cu_inl_function_cache[function->addr]; - if (v == 0) - { - v = new vector<Dwarf_Die>; - cu_inl_function_cache[function->addr] = v; - dwarf_func_inline_instances (function, cu_inl_function_caching_callback, v); - } + if (!v) + return; for (vector<Dwarf_Die>::iterator i = v->begin(); i != v->end(); ++i) { |