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8315031: YoungPLABSize and OldPLABSize not aligned by ObjectAlignment…
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Reviewed-by: tschatzl, iwalulya
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albertnetymk committed Sep 28, 2023
1 parent 3481a48 commit 060db1b
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Showing 2 changed files with 10 additions and 1 deletion.
4 changes: 3 additions & 1 deletion src/hotspot/share/gc/g1/g1EvacStats.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -133,7 +133,9 @@ G1EvacStats::G1EvacStats(const char* description, size_t default_per_thread_plab
// Calculates plab size for current number of gc worker threads.
size_t G1EvacStats::desired_plab_size(uint no_of_gc_workers) const {
if (!ResizePLAB) {
return _default_plab_size;
// There is a circular dependency between the heap and PLAB initialization,
// so _default_plab_size can have an unaligned value.
return align_object_size(_default_plab_size);
return align_object_size(clamp(_desired_net_plab_size / no_of_gc_workers, min_size(), max_size()));
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7 changes: 7 additions & 0 deletions src/hotspot/share/gc/shared/plab.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,13 @@ void PLAB::startup_initialization() {
FLAG_SET_ERGO(OldPLABSize, MAX2(ThreadLocalAllocBuffer::min_size(), OldPLABSize));
uint obj_alignment = checked_cast<uint>(ObjectAlignmentInBytes / HeapWordSize);
if (!is_aligned(YoungPLABSize, obj_alignment)) {
FLAG_SET_ERGO(YoungPLABSize, align_up(YoungPLABSize, obj_alignment));
if (!is_aligned(OldPLABSize, obj_alignment)) {
FLAG_SET_ERGO(OldPLABSize, align_up(OldPLABSize, obj_alignment));

PLAB::PLAB(size_t desired_plab_sz_) :
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