Skip to content

Commit

Permalink
8341485: GenShen: Make evac tracker a non-product feature and confine…
Browse files Browse the repository at this point in the history 
… it to generational mode

Reviewed-by: kdnilsen, ysr
  • Loading branch information
William Kemper committed Oct 4, 2024
1 parent a3db9e6 commit bd7d34d
Show file tree
Hide file tree
Showing 10 changed files with 60 additions and 55 deletions.
32 changes: 16 additions & 16 deletions src/hotspot/share/gc/shenandoah/shenandoahEvacTracker.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -27,14 +27,13 @@
#include "gc/shenandoah/shenandoahHeap.inline.hpp"
#include "gc/shenandoah/shenandoahEvacTracker.hpp"
#include "gc/shenandoah/shenandoahThreadLocalData.hpp"
#include "gc/shenandoah/shenandoahRootProcessor.hpp"
#include "runtime/threadSMR.inline.hpp"
#include "runtime/thread.hpp"

ShenandoahEvacuationStats::ShenandoahEvacuationStats(bool generational)
ShenandoahEvacuationStats::ShenandoahEvacuationStats()
: _evacuations_completed(0), _bytes_completed(0),
_evacuations_attempted(0), _bytes_attempted(0),
_use_age_table(generational && (ShenandoahGenerationalCensusAtEvac || !ShenandoahGenerationalAdaptiveTenuring)) {
_use_age_table(ShenandoahGenerationalCensusAtEvac || !ShenandoahGenerationalAdaptiveTenuring) {
if (_use_age_table) {
_age_table = new AgeTable(false);
}
Expand Down Expand Up @@ -81,6 +80,7 @@ void ShenandoahEvacuationStats::reset() {
}

void ShenandoahEvacuationStats::print_on(outputStream* st) {
#ifndef PRODUCT
size_t abandoned_size = _bytes_attempted - _bytes_completed;
size_t abandoned_count = _evacuations_attempted - _evacuations_completed;
st->print_cr("Evacuated " SIZE_FORMAT "%s across " SIZE_FORMAT " objects, "
Expand All @@ -89,6 +89,7 @@ void ShenandoahEvacuationStats::print_on(outputStream* st) {
_evacuations_completed,
byte_size_in_proper_unit(abandoned_size), proper_unit_for_byte_size(abandoned_size),
abandoned_count);
#endif
if (_use_age_table) {
_age_table->print_on(st);
}
Expand All @@ -109,33 +110,32 @@ void ShenandoahEvacuationTracker::print_evacuations_on(outputStream* st,
st->cr();

ShenandoahHeap* heap = ShenandoahHeap::heap();
if (_generational) {
AgeTable young_region_ages(false);
for (uint i = 0; i < heap->num_regions(); ++i) {
ShenandoahHeapRegion* r = heap->get_region(i);
if (r->is_young()) {
young_region_ages.add(r->age(), r->get_live_data_words());
}

AgeTable young_region_ages(false);
for (uint i = 0; i < heap->num_regions(); ++i) {
ShenandoahHeapRegion* r = heap->get_region(i);
if (r->is_young()) {
young_region_ages.add(r->age(), r->get_live_data_words());
}
st->print("Young regions: ");
young_region_ages.print_on(st);
st->cr();
}
st->print("Young regions: ");
young_region_ages.print_on(st);
st->cr();
}

class ShenandoahStatAggregator : public ThreadClosure {
public:
ShenandoahEvacuationStats* _target;
explicit ShenandoahStatAggregator(ShenandoahEvacuationStats* target) : _target(target) {}
virtual void do_thread(Thread* thread) override {
void do_thread(Thread* thread) override {
ShenandoahEvacuationStats* local = ShenandoahThreadLocalData::evacuation_stats(thread);
_target->accumulate(local);
local->reset();
}
};

ShenandoahCycleStats ShenandoahEvacuationTracker::flush_cycle_to_global() {
ShenandoahEvacuationStats mutators(_generational), workers(_generational);
ShenandoahEvacuationStats mutators, workers;

ThreadsListHandle java_threads_iterator;
ShenandoahStatAggregator aggregate_mutators(&mutators);
Expand All @@ -147,7 +147,7 @@ ShenandoahCycleStats ShenandoahEvacuationTracker::flush_cycle_to_global() {
_mutators_global.accumulate(&mutators);
_workers_global.accumulate(&workers);

if (_generational && (ShenandoahGenerationalCensusAtEvac || !ShenandoahGenerationalAdaptiveTenuring)) {
if (ShenandoahGenerationalCensusAtEvac || !ShenandoahGenerationalAdaptiveTenuring) {
// Ingest mutator & worker collected population vectors into the heap's
// global census data, and use it to compute an appropriate tenuring threshold
// for use in the next cycle.
Expand Down
12 changes: 4 additions & 8 deletions src/hotspot/share/gc/shenandoah/shenandoahEvacTracker.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -39,7 +39,7 @@ class ShenandoahEvacuationStats : public CHeapObj<mtGC> {
AgeTable* _age_table;

public:
ShenandoahEvacuationStats(bool generational);
ShenandoahEvacuationStats();

AgeTable* age_table() const;

Expand All @@ -59,25 +59,21 @@ struct ShenandoahCycleStats {

class ShenandoahEvacuationTracker : public CHeapObj<mtGC> {
private:
bool _generational;

ShenandoahEvacuationStats _workers_global;
ShenandoahEvacuationStats _mutators_global;

public:
ShenandoahEvacuationTracker(bool generational) :
_generational(generational),
_workers_global(generational),
_mutators_global(generational) {}
ShenandoahEvacuationTracker() = default;

void begin_evacuation(Thread* thread, size_t bytes);
void end_evacuation(Thread* thread, size_t bytes);
void record_age(Thread* thread, size_t bytes, uint age);

void print_global_on(outputStream* st);
void print_evacuations_on(outputStream* st,
ShenandoahEvacuationStats* workers,
ShenandoahEvacuationStats* mutators);
ShenandoahEvacuationStats* workers,
ShenandoahEvacuationStats* mutators);

ShenandoahCycleStats flush_cycle_to_global();
};
Expand Down
11 changes: 6 additions & 5 deletions src/hotspot/share/gc/shenandoah/shenandoahGenerationalControlThread.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,7 @@
#include "gc/shenandoah/shenandoahFreeSet.hpp"
#include "gc/shenandoah/shenandoahFullGC.hpp"
#include "gc/shenandoah/shenandoahGeneration.hpp"
#include "gc/shenandoah/shenandoahGenerationalHeap.hpp"
#include "gc/shenandoah/shenandoahOldGC.hpp"
#include "gc/shenandoah/shenandoahOldGeneration.hpp"
#include "gc/shenandoah/shenandoahHeap.inline.hpp"
Expand Down Expand Up @@ -337,7 +338,7 @@ void ShenandoahGenerationalControlThread::run_service() {
}
}

void ShenandoahGenerationalControlThread::process_phase_timings(const ShenandoahHeap* heap) {
void ShenandoahGenerationalControlThread::process_phase_timings(const ShenandoahGenerationalHeap* heap) {
// Commit worker statistics to cycle data
heap->phase_timings()->flush_par_workers_to_cycle();
if (ShenandoahPacing) {
Expand Down Expand Up @@ -391,9 +392,9 @@ void ShenandoahGenerationalControlThread::process_phase_timings(const Shenandoah
// | v v |
// +---> Global Degen +--------------------> Full <----+
//
void ShenandoahGenerationalControlThread::service_concurrent_normal_cycle(ShenandoahHeap* heap,
const ShenandoahGenerationType generation,
GCCause::Cause cause) {
void ShenandoahGenerationalControlThread::service_concurrent_normal_cycle(ShenandoahGenerationalHeap* heap,
const ShenandoahGenerationType generation,
GCCause::Cause cause) {
GCIdMark gc_id_mark;
switch (generation) {
case YOUNG: {
Expand Down Expand Up @@ -421,7 +422,7 @@ void ShenandoahGenerationalControlThread::service_concurrent_normal_cycle(Shenan
}
}

void ShenandoahGenerationalControlThread::service_concurrent_old_cycle(ShenandoahHeap* heap, GCCause::Cause &cause) {
void ShenandoahGenerationalControlThread::service_concurrent_old_cycle(ShenandoahGenerationalHeap* heap, GCCause::Cause &cause) {
ShenandoahOldGeneration* old_generation = heap->old_generation();
ShenandoahYoungGeneration* young_generation = heap->young_generation();
ShenandoahOldGeneration::State original_state = old_generation->state();
Expand Down
11 changes: 7 additions & 4 deletions src/hotspot/share/gc/shenandoah/shenandoahGenerationalControlThread.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -28,12 +28,15 @@

#include "gc/shared/gcCause.hpp"
#include "gc/shenandoah/shenandoahController.hpp"
#include "gc/shenandoah/shenandoahGenerationType.hpp"
#include "gc/shenandoah/shenandoahGC.hpp"
#include "gc/shenandoah/shenandoahHeap.hpp"
#include "gc/shenandoah/shenandoahPadding.hpp"
#include "gc/shenandoah/shenandoahSharedVariables.hpp"

class ShenandoahOldGeneration;
class ShenandoahGeneration;
class ShenandoahGenerationalHeap;
class ShenandoahHeap;

class ShenandoahGenerationalControlThread: public ShenandoahController {
friend class VMStructs;
Expand Down Expand Up @@ -101,13 +104,13 @@ class ShenandoahGenerationalControlThread: public ShenandoahController {
// Returns true if the old generation marking was interrupted to allow a young cycle.
bool preempt_old_marking(ShenandoahGenerationType generation);

void process_phase_timings(const ShenandoahHeap* heap);
void process_phase_timings(const ShenandoahGenerationalHeap* heap);

void service_concurrent_normal_cycle(ShenandoahHeap* heap,
void service_concurrent_normal_cycle(ShenandoahGenerationalHeap* heap,
ShenandoahGenerationType generation,
GCCause::Cause cause);

void service_concurrent_old_cycle(ShenandoahHeap* heap,
void service_concurrent_old_cycle(ShenandoahGenerationalHeap* heap,
GCCause::Cause &cause);

void set_gc_mode(GCMode new_mode);
Expand Down
17 changes: 15 additions & 2 deletions src/hotspot/share/gc/shenandoah/shenandoahGenerationalHeap.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -95,6 +95,7 @@ size_t ShenandoahGenerationalHeap::unsafe_max_tlab_alloc(Thread *thread) const {
ShenandoahGenerationalHeap::ShenandoahGenerationalHeap(ShenandoahCollectorPolicy* policy) :
ShenandoahHeap(policy),
_age_census(nullptr),
_evac_tracker(new ShenandoahEvacuationTracker()),
_min_plab_size(calculate_min_plab()),
_max_plab_size(calculate_max_plab()),
_regulator_thread(nullptr),
Expand All @@ -114,6 +115,18 @@ void ShenandoahGenerationalHeap::print_init_logger() const {
logger.print_all();
}

void ShenandoahGenerationalHeap::print_tracing_info() const {
ShenandoahHeap::print_tracing_info();

LogTarget(Info, gc, stats) lt;
if (lt.is_enabled()) {
LogStream ls(lt);
ls.cr();
ls.cr();
evac_tracker()->print_global_on(&ls);
}
}

void ShenandoahGenerationalHeap::initialize_heuristics() {
// Initialize global generation and heuristics even in generational mode.
ShenandoahHeap::initialize_heuristics();
Expand Down Expand Up @@ -317,7 +330,7 @@ oop ShenandoahGenerationalHeap::try_evacuate_object(oop p, Thread* thread, Shena
}

// Copy the object:
evac_tracker()->begin_evacuation(thread, size * HeapWordSize);
NOT_PRODUCT(evac_tracker()->begin_evacuation(thread, size * HeapWordSize));
Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(p), copy, size);
oop copy_val = cast_to_oop(copy);

Expand All @@ -339,7 +352,7 @@ oop ShenandoahGenerationalHeap::try_evacuate_object(oop p, Thread* thread, Shena
ContinuationGCSupport::relativize_stack_chunk(copy_val);

// Record that the evacuation succeeded
evac_tracker()->end_evacuation(thread, size * HeapWordSize);
NOT_PRODUCT(evac_tracker()->end_evacuation(thread, size * HeapWordSize));

if (target_gen == OLD_GENERATION) {
old_generation()->handle_evacuation(copy, size, from_region->is_young());
Expand Down
8 changes: 8 additions & 0 deletions src/hotspot/share/gc/shenandoah/shenandoahGenerationalHeap.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -53,6 +53,8 @@ class ShenandoahGenerationalHeap : public ShenandoahHeap {
}

void print_init_logger() const override;
void print_tracing_info() const override;

size_t unsafe_max_tlab_alloc(Thread *thread) const override;

private:
Expand All @@ -62,6 +64,8 @@ class ShenandoahGenerationalHeap : public ShenandoahHeap {
ShenandoahSharedFlag _is_aging_cycle;
// Age census used for adapting tenuring threshold
ShenandoahAgeCensus* _age_census;
// Used primarily to look for failed evacuation attempts.
ShenandoahEvacuationTracker* _evac_tracker;

public:
void set_aging_cycle(bool cond) {
Expand All @@ -77,6 +81,10 @@ class ShenandoahGenerationalHeap : public ShenandoahHeap {
return _age_census;
}

ShenandoahEvacuationTracker* evac_tracker() const {
return _evac_tracker;
}

// Ages regions that haven't been used for allocations in the current cycle.
// Resets ages for regions that have been used for allocations.
void update_region_ages(ShenandoahMarkingContext* ctx);
Expand Down
16 changes: 0 additions & 16 deletions src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -501,7 +501,6 @@ void ShenandoahHeap::initialize_mode() {
void ShenandoahHeap::initialize_heuristics() {
_global_generation = new ShenandoahGlobalGeneration(mode()->is_generational(), max_workers(), max_capacity(), max_capacity());
_global_generation->initialize_heuristics(mode());
_evac_tracker = new ShenandoahEvacuationTracker(mode()->is_generational());
}

#ifdef _MSC_VER
Expand Down Expand Up @@ -536,7 +535,6 @@ ShenandoahHeap::ShenandoahHeap(ShenandoahCollectorPolicy* policy) :
_pacer(nullptr),
_verifier(nullptr),
_phase_timings(nullptr),
_evac_tracker(nullptr),
_mmu_tracker(),
_monitoring_support(nullptr),
_memory_pool(nullptr),
Expand Down Expand Up @@ -1247,15 +1245,7 @@ oop ShenandoahHeap::try_evacuate_object(oop p, Thread* thread, ShenandoahHeapReg
#endif
if (UseTLAB) {
copy = allocate_from_gclab(thread, size);
if ((copy == nullptr) && (size < ShenandoahThreadLocalData::gclab_size(thread))) {
// GCLAB allocation failed because we are bumping up against the limit on young evacuation reserve. Try resetting
// the desired GCLAB size and retry GCLAB allocation to avoid cascading of shared memory allocations.
ShenandoahThreadLocalData::set_gclab_size(thread, PLAB::min_size());
copy = allocate_from_gclab(thread, size);
// If we still get nullptr, we'll try a shared allocation below.
}
}

if (copy == nullptr) {
// If we failed to allocate in LAB, we'll try a shared allocation.
ShenandoahAllocRequest req = ShenandoahAllocRequest::for_shared_gc(size, target_gen);
Expand All @@ -1275,7 +1265,6 @@ oop ShenandoahHeap::try_evacuate_object(oop p, Thread* thread, ShenandoahHeapReg
}

// Copy the object:
_evac_tracker->begin_evacuation(thread, size * HeapWordSize);
Copy::aligned_disjoint_words(cast_from_oop<HeapWord*>(p), copy, size);

// Try to install the new forwarding pointer.
Expand All @@ -1284,7 +1273,6 @@ oop ShenandoahHeap::try_evacuate_object(oop p, Thread* thread, ShenandoahHeapReg
if (result == copy_val) {
// Successfully evacuated. Our copy is now the public one!
ContinuationGCSupport::relativize_stack_chunk(copy_val);
_evac_tracker->end_evacuation(thread, size * HeapWordSize);
shenandoah_assert_correct(nullptr, copy_val);
return copy_val;
} else {
Expand Down Expand Up @@ -1531,10 +1519,6 @@ void ShenandoahHeap::print_tracing_info() const {

shenandoah_policy()->print_gc_stats(&ls);

ls.cr();

evac_tracker()->print_global_on(&ls);

ls.cr();
ls.cr();
}
Expand Down
2 changes: 0 additions & 2 deletions src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -509,7 +509,6 @@ class ShenandoahHeap : public CollectedHeap {
ShenandoahVerifier* _verifier;

ShenandoahPhaseTimings* _phase_timings;
ShenandoahEvacuationTracker* _evac_tracker;
ShenandoahMmuTracker _mmu_tracker;

public:
Expand All @@ -534,7 +533,6 @@ class ShenandoahHeap : public CollectedHeap {
ShenandoahPacer* pacer() const { return _pacer; }

ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; }
ShenandoahEvacuationTracker* evac_tracker() const { return _evac_tracker; }

ShenandoahEvacOOMHandler* oom_evac_handler() { return &_oom_evac_handler; }

Expand Down
5 changes: 3 additions & 2 deletions src/hotspot/share/gc/shenandoah/shenandoahThreadLocalData.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -46,8 +46,9 @@ ShenandoahThreadLocalData::ShenandoahThreadLocalData() :
_plab_allows_promotion(true),
_plab_retries_enabled(true),
_evacuation_stats(nullptr) {
bool gen_mode = ShenandoahHeap::heap()->mode()->is_generational();
_evacuation_stats = new ShenandoahEvacuationStats(gen_mode);
if (ShenandoahHeap::heap()->mode()->is_generational()) {
_evacuation_stats = new ShenandoahEvacuationStats();
}
}

ShenandoahThreadLocalData::~ShenandoahThreadLocalData() {
Expand Down
1 change: 1 addition & 0 deletions src/hotspot/share/gc/shenandoah/shenandoahThreadLocalData.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -152,6 +152,7 @@ class ShenandoahThreadLocalData {
}

static ShenandoahEvacuationStats* evacuation_stats(Thread* thread) {
shenandoah_assert_generational();
return data(thread)->_evacuation_stats;
}

Expand Down

2 comments on commit bd7d34d

@earthling-amzn
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

/backport shenandoah-jdk21u

@openjdk
Copy link

@openjdk openjdk bot commented on bd7d34d Oct 4, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

@earthling-amzn Could not automatically backport bd7d34d8 to openjdk/shenandoah-jdk21u due to conflicts in the following files:

  • src/hotspot/share/gc/shenandoah/shenandoahEvacTracker.cpp
  • src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp

Please fetch the appropriate branch/commit and manually resolve these conflicts by using the following commands in your personal fork of openjdk/shenandoah-jdk21u. Note: these commands are just some suggestions and you can use other equivalent commands you know.

# Fetch the up-to-date version of the target branch
$ git fetch --no-tags https://git.openjdk.org/shenandoah-jdk21u.git master:master

# Check out the target branch and create your own branch to backport
$ git checkout master
$ git checkout -b backport-earthling-amzn-bd7d34d8-master

# Fetch the commit you want to backport
$ git fetch --no-tags https://git.openjdk.org/shenandoah.git bd7d34d8e4c89a855a2398965f776803ded557ea

# Backport the commit
$ git cherry-pick --no-commit bd7d34d8e4c89a855a2398965f776803ded557ea
# Resolve conflicts now

# Commit the files you have modified
$ git add files/with/resolved/conflicts
$ git commit -m 'Backport bd7d34d8e4c89a855a2398965f776803ded557ea'

Once you have resolved the conflicts as explained above continue with creating a pull request towards the openjdk/shenandoah-jdk21u with the title Backport bd7d34d8e4c89a855a2398965f776803ded557ea.

Below you can find a suggestion for the pull request body:

Hi all,

This pull request contains a backport of commit bd7d34d8 from the openjdk/shenandoah repository.

The commit being backported was authored by William Kemper on 4 Oct 2024 and was reviewed by Kelvin Nilsen and Y. Srinivas Ramakrishna.

Thanks!

Please sign in to comment.