Mercurial > hg > truffle
diff src/share/vm/code/nmethod.cpp @ 20619:b12a2a9b05ca
8056240: Investigate increased GC remark time after class unloading changes in CRM Fuse
Reviewed-by: mgerdin, coleenp, bdelsart
author | stefank |
---|---|
date | Thu, 02 Oct 2014 10:55:36 +0200 |
parents | 2c6ef90f030a |
children | 7848fc12602b |
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--- a/src/share/vm/code/nmethod.cpp Mon Nov 03 12:02:40 2014 -0800 +++ b/src/share/vm/code/nmethod.cpp Thu Oct 02 10:55:36 2014 +0200 @@ -1720,11 +1720,17 @@ set_unload_reported(); } -void static clean_ic_if_metadata_is_dead(CompiledIC *ic, BoolObjectClosure *is_alive) { +void static clean_ic_if_metadata_is_dead(CompiledIC *ic, BoolObjectClosure *is_alive, bool mark_on_stack) { if (ic->is_icholder_call()) { // The only exception is compiledICHolder oops which may // yet be marked below. (We check this further below). CompiledICHolder* cichk_oop = ic->cached_icholder(); + + if (mark_on_stack) { + Metadata::mark_on_stack(cichk_oop->holder_method()); + Metadata::mark_on_stack(cichk_oop->holder_klass()); + } + if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) && cichk_oop->holder_klass()->is_loader_alive(is_alive)) { return; @@ -1732,6 +1738,10 @@ } else { Metadata* ic_oop = ic->cached_metadata(); if (ic_oop != NULL) { + if (mark_on_stack) { + Metadata::mark_on_stack(ic_oop); + } + if (ic_oop->is_klass()) { if (((Klass*)ic_oop)->is_loader_alive(is_alive)) { return; @@ -1792,7 +1802,7 @@ while(iter.next()) { if (iter.type() == relocInfo::virtual_call_type) { CompiledIC *ic = CompiledIC_at(&iter); - clean_ic_if_metadata_is_dead(ic, is_alive); + clean_ic_if_metadata_is_dead(ic, is_alive, false); } } } @@ -1860,6 +1870,53 @@ return clean_if_nmethod_is_unloaded(csc, csc->destination(), is_alive, from); } +bool nmethod::unload_if_dead_at(RelocIterator* iter_at_oop, BoolObjectClosure *is_alive, bool unloading_occurred) { + assert(iter_at_oop->type() == relocInfo::oop_type, "Wrong relocation type"); + + oop_Relocation* r = iter_at_oop->oop_reloc(); + // Traverse those oops directly embedded in the code. + // Other oops (oop_index>0) are seen as part of scopes_oops. + assert(1 == (r->oop_is_immediate()) + + (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()), + "oop must be found in exactly one place"); + if (r->oop_is_immediate() && r->oop_value() != NULL) { + // Unload this nmethod if the oop is dead. + if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) { + return true;; + } + } + + return false; +} + +void nmethod::mark_metadata_on_stack_at(RelocIterator* iter_at_metadata) { + assert(iter_at_metadata->type() == relocInfo::metadata_type, "Wrong relocation type"); + + metadata_Relocation* r = iter_at_metadata->metadata_reloc(); + // In this metadata, we must only follow those metadatas directly embedded in + // the code. Other metadatas (oop_index>0) are seen as part of + // the metadata section below. + assert(1 == (r->metadata_is_immediate()) + + (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()), + "metadata must be found in exactly one place"); + if (r->metadata_is_immediate() && r->metadata_value() != NULL) { + Metadata* md = r->metadata_value(); + if (md != _method) Metadata::mark_on_stack(md); + } +} + +void nmethod::mark_metadata_on_stack_non_relocs() { + // Visit the metadata section + for (Metadata** p = metadata_begin(); p < metadata_end(); p++) { + if (*p == Universe::non_oop_word() || *p == NULL) continue; // skip non-oops + Metadata* md = *p; + Metadata::mark_on_stack(md); + } + + // Visit metadata not embedded in the other places. + if (_method != NULL) Metadata::mark_on_stack(_method); +} + bool nmethod::do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred) { ResourceMark rm; @@ -1889,6 +1946,11 @@ unloading_occurred = true; } + // When class redefinition is used all metadata in the CodeCache has to be recorded, + // so that unused "previous versions" can be purged. Since walking the CodeCache can + // be expensive, the "mark on stack" is piggy-backed on this parallel unloading code. + bool mark_metadata_on_stack = a_class_was_redefined; + // Exception cache clean_exception_cache(is_alive); @@ -1904,7 +1966,7 @@ if (unloading_occurred) { // If class unloading occurred we first iterate over all inline caches and // clear ICs where the cached oop is referring to an unloaded klass or method. - clean_ic_if_metadata_is_dead(CompiledIC_at(&iter), is_alive); + clean_ic_if_metadata_is_dead(CompiledIC_at(&iter), is_alive, mark_metadata_on_stack); } postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this); @@ -1920,24 +1982,21 @@ case relocInfo::oop_type: if (!is_unloaded) { - // Unload check - oop_Relocation* r = iter.oop_reloc(); - // Traverse those oops directly embedded in the code. - // Other oops (oop_index>0) are seen as part of scopes_oops. - assert(1 == (r->oop_is_immediate()) + - (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()), - "oop must be found in exactly one place"); - if (r->oop_is_immediate() && r->oop_value() != NULL) { - if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) { - is_unloaded = true; - } - } + is_unloaded = unload_if_dead_at(&iter, is_alive, unloading_occurred); } break; + case relocInfo::metadata_type: + if (mark_metadata_on_stack) { + mark_metadata_on_stack_at(&iter); + } } } + if (mark_metadata_on_stack) { + mark_metadata_on_stack_non_relocs(); + } + if (is_unloaded) { return postponed; } @@ -2085,7 +2144,7 @@ while (iter.next()) { if (iter.type() == relocInfo::metadata_type ) { metadata_Relocation* r = iter.metadata_reloc(); - // In this lmetadata, we must only follow those metadatas directly embedded in + // In this metadata, we must only follow those metadatas directly embedded in // the code. Other metadatas (oop_index>0) are seen as part of // the metadata section below. assert(1 == (r->metadata_is_immediate()) + @@ -2119,7 +2178,7 @@ f(md); } - // Call function Method*, not embedded in these other places. + // Visit metadata not embedded in the other places. if (_method != NULL) f(_method); }