imgdiag: don't compare zygote to bootimage
Currently imgdiag outputs a lot of zygote "different entries" due to
address space randomization.
Zygote memory relocations happen before it starts forking app processes,
so most of the reported different entries are shared dirty.
This CL makes imgdiag output entries differing between zygote and child
processes, which are more of interest.
Before this change (same process, boot.art):
13986 different entries,
1169382 different entry [bytes],
After:
84 different entries,
17052 different entry [bytes],
Test: m imgdiag
Change-Id: I2350866680f341a8d3509c63275596a74f50bd2c
diff --git a/imgdiag/imgdiag.cc b/imgdiag/imgdiag.cc
index 886e0bb..404be09 100644
--- a/imgdiag/imgdiag.cc
+++ b/imgdiag/imgdiag.cc
@@ -268,7 +268,6 @@
size_t GetDirtyEntryBytes() const { return dirty_entry_bytes_; }
size_t GetFalseDirtyEntryCount() const { return false_dirty_entries_.size(); }
size_t GetFalseDirtyEntryBytes() const { return false_dirty_entry_bytes_; }
- size_t GetZygoteDirtyEntryCount() const { return zygote_dirty_entries_.size(); }
protected:
bool IsEntryOnDirtyPage(T* entry, const std::set<size_t>& dirty_pages) const
@@ -289,10 +288,6 @@
return false;
}
- void AddZygoteDirtyEntry(T* entry) REQUIRES_SHARED(Locks::mutator_lock_) {
- zygote_dirty_entries_.insert(entry);
- }
-
void AddImageDirtyEntry(T* entry) REQUIRES_SHARED(Locks::mutator_lock_) {
image_dirty_entries_.insert(entry);
}
@@ -327,11 +322,6 @@
// If zygote_pid_only_ == false, these are private dirty entries in the application.
std::set<T*> image_dirty_entries_;
- // Zygote dirty entries (probably private dirty).
- // We only add entries here if they differed in both the image and the zygote, so
- // they are probably private dirty.
- std::set<T*> zygote_dirty_entries_;
-
std::map<off_t /* field offset */, size_t /* count */> field_dirty_count_;
private:
@@ -1009,24 +999,11 @@
os_ << " Application dirty entries (unknown whether private or shared dirty): ";
break;
}
- DiffDirtyEntries(ProcessType::kRemote,
+ DiffDirtyEntries(RegionCommon<T>::image_dirty_entries_,
begin_image_ptr,
RegionCommon<T>::remote_contents_,
base_ptr,
/*log_dirty_objects=*/true);
- // Print shared dirty after since it's less important.
- if (RegionCommon<T>::GetZygoteDirtyEntryCount() != 0) {
- // We only reach this point if both pids were specified. Furthermore,
- // entries are only displayed here if they differed in both the image
- // and the zygote, so they are probably private dirty.
- CHECK(remotes == RemoteProcesses::kImageAndZygote);
- os_ << "\n" << " Zygote dirty entries (probably shared dirty): ";
- DiffDirtyEntries(ProcessType::kZygote,
- begin_image_ptr,
- RegionCommon<T>::zygote_contents_,
- begin_image_ptr,
- /*log_dirty_objects=*/false);
- }
RegionSpecializedBase<T>::DumpDirtyObjects();
RegionSpecializedBase<T>::DumpDirtyEntries();
RegionSpecializedBase<T>::DumpFalseDirtyEntries();
@@ -1036,17 +1013,13 @@
private:
std::ostream& os_;
- void DiffDirtyEntries(ProcessType process_type,
+ void DiffDirtyEntries(const std::set<T*>& entries,
const uint8_t* begin_image_ptr,
ArrayRef<uint8_t> contents,
const uint8_t* base_ptr,
bool log_dirty_objects)
REQUIRES_SHARED(Locks::mutator_lock_) {
os_ << RegionCommon<T>::dirty_entries_.size() << "\n";
- const std::set<T*>& entries =
- (process_type == ProcessType::kZygote) ?
- RegionCommon<T>::zygote_dirty_entries_:
- RegionCommon<T>::image_dirty_entries_;
for (T* entry : entries) {
uint8_t* entry_bytes = reinterpret_cast<uint8_t*>(entry);
ptrdiff_t offset = entry_bytes - begin_image_ptr;
@@ -1077,17 +1050,11 @@
// Test private dirty first.
bool is_dirty = false;
if (have_zygote) {
- bool private_dirty = EntriesDiffer(entry, entry_zygote, entry_remote);
- if (private_dirty) {
+ if (EntriesDiffer(entry, entry_zygote, entry_remote)) {
// Private dirty, app vs zygote.
is_dirty = true;
RegionCommon<T>::AddImageDirtyEntry(entry);
}
- if (EntriesDiffer(entry, entry_zygote, entry)) {
- // Shared dirty, zygote vs image.
- is_dirty = true;
- RegionCommon<T>::AddZygoteDirtyEntry(entry);
- }
} else if (EntriesDiffer(entry, entry_remote, entry)) {
// Shared or private dirty, app vs image.
is_dirty = true;