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Ensure regions will always have enough memory for the bookkeeping #75038

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Ensure regions will always have enough memory for the bookkeeping #75038

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88 changes: 78 additions & 10 deletions src/coreclr/gc/gc.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2331,7 +2331,12 @@ size_t gc_heap::heap_hard_limit = 0;
size_t gc_heap::heap_hard_limit_oh[total_oh_count];

#ifdef USE_REGIONS

size_t gc_heap::regions_range = 0;

size_t gc_heap::heap_hard_limit_for_heap = 0;
size_t gc_heap::heap_hard_limit_for_bookkeeping = 0;

#endif //USE_REGIONS

bool affinity_config_specified_p = false;
Expand Down Expand Up @@ -6898,6 +6903,14 @@ bool gc_heap::virtual_alloc_commit_for_heap (void* addr, size_t size, int h_numb

bool gc_heap::virtual_commit (void* address, size_t size, int bucket, int h_number, bool* hard_limit_exceeded_p)
{
/**
* Here are all the possible cases for the commits:
*
* Case 1: This is for a particular generation - the bucket will be one of the gc_oh_num != unknown, and the h_number will be the right heap
* Case 2: This is for bookkeeping - the bucket will be recorded_committed_bookkeeping_bucket, and the h_number will be -1
*
* Note : We never commit into free directly, so bucket != recorded_committed_free_bucket
*/
#ifndef HOST_64BIT
assert (heap_hard_limit == 0);
#endif //!HOST_64BIT
Expand All @@ -6913,21 +6926,41 @@ bool gc_heap::virtual_commit (void* address, size_t size, int bucket, int h_numb
check_commit_cs.Enter();
bool exceeded_p = false;

if (heap_hard_limit_oh[bucket] != 0)
if ((heap_hard_limit_oh[soh] != 0) && (bucket < total_oh_count) && (heap_hard_limit_oh[bucket] != 0))
{
if ((bucket < total_oh_count) && (committed_by_oh[bucket] + size) > heap_hard_limit_oh[bucket])
{
exceeded_p = true;
}
}
else if ((current_total_committed + size) > heap_hard_limit)
else
{
dprintf (1, ("%Id + %Id = %Id > limit %Id ",
current_total_committed, size,
(current_total_committed + size),
heap_hard_limit));
size_t base;
size_t limit;
#ifdef USE_REGIONS
if (h_number < 0)
{
base = current_total_committed_bookkeeping;
limit = heap_hard_limit_for_bookkeeping;
}
else
{
base = current_total_committed - current_total_committed_bookkeeping;
limit = heap_hard_limit_for_heap;
}
#else
base = current_total_committed;
limit = heap_hard_limit;
#endif
if ((base + size) > limit)
{
dprintf (1, ("%Id + %Id = %Id > limit %Id ",
base, size,
(base + size),
limit));

exceeded_p = true;
exceeded_p = true;
}
}

if (!exceeded_p)
Expand Down Expand Up @@ -6977,7 +7010,10 @@ bool gc_heap::virtual_commit (void* address, size_t size, int bucket, int h_numb
current_total_committed, (current_total_committed - size)));
current_total_committed -= size;
if (h_number < 0)
{
assert (current_total_committed_bookkeeping >= size);
current_total_committed_bookkeeping -= size;
}

check_commit_cs.Leave();
}
Expand All @@ -6986,6 +7022,13 @@ bool gc_heap::virtual_commit (void* address, size_t size, int bucket, int h_numb

bool gc_heap::virtual_decommit (void* address, size_t size, int bucket, int h_number)
{
/**
* Here are all possible cases for the decommits:
*
* Case 1: This is for a particular generation - the bucket will be one of the gc_oh_num != unknown, and the h_number will be the right heap
* Case 2: This is for bookkeeping - the bucket will be recorded_committed_bookkeeping_bucket, and the h_number will be -1
* Case 3: This is for free - the bucket will be recorded_committed_free_bucket, and the h_number will be -1
*/
#ifndef HOST_64BIT
assert (heap_hard_limit == 0);
#endif //!HOST_64BIT
Expand All @@ -7009,9 +7052,13 @@ bool gc_heap::virtual_decommit (void* address, size_t size, int bucket, int h_nu
g_heaps[h_number]->committed_by_oh_per_heap[bucket] -= size;
}
#endif // _DEBUG && MULTIPLE_HEAPS
assert (current_total_committed >= size);
current_total_committed -= size;
if (h_number < 0)
if (bucket == recorded_committed_bookkeeping_bucket)
{
assert (current_total_committed_bookkeeping >= size);
current_total_committed_bookkeeping -= size;
}
check_commit_cs.Leave();
}

Expand Down Expand Up @@ -8726,10 +8773,10 @@ bool gc_heap::on_used_changed (uint8_t* new_used)
{
if (new_bookkeeping_covered_committed == new_used)
{
dprintf (REGIONS_LOG, ("The minimal commit for the GC bookkeepping data structure failed, giving up"));
dprintf (REGIONS_LOG, ("The minimal commit for the GC bookkeeping data structure failed, giving up"));
return false;
}
dprintf (REGIONS_LOG, ("The speculative commit for the GC bookkeepping data structure failed, retry for minimal commit"));
dprintf (REGIONS_LOG, ("The speculative commit for the GC bookkeeping data structure failed, retry for minimal commit"));
speculative_commit_tried = true;
}
}
Expand Down Expand Up @@ -13419,6 +13466,26 @@ HRESULT gc_heap::initialize_gc (size_t soh_segment_size,
#endif //BACKGROUND_GC
#endif //WRITE_WATCH

#ifdef USE_REGIONS
if (gc_heap::heap_hard_limit)
{
size_t gc_region_size = (size_t)1 << min_segment_size_shr;
size_t sizes[total_bookkeeping_elements];
size_t bookkeeping_size_per_region = 0;
uint8_t* temp_lowest_address = (uint8_t*)gc_region_size;
gc_heap::get_card_table_element_sizes(temp_lowest_address, temp_lowest_address + gc_region_size, sizes);
for (int i = 0; i < total_bookkeeping_elements; i++)
{
bookkeeping_size_per_region += sizes[i];
}
size_t total_size_per_region = gc_region_size + bookkeeping_size_per_region;
size_t max_region_count = gc_heap::heap_hard_limit / total_size_per_region; // implictly rounded down
gc_heap::heap_hard_limit_for_heap = max_region_count * gc_region_size;
gc_heap::heap_hard_limit_for_bookkeeping = max_region_count * bookkeeping_size_per_region;
dprintf (REGIONS_LOG, ("bookkeeping_size_per_region = %Id", bookkeeping_size_per_region));
}
#endif //USE_REGIONS

#ifdef BACKGROUND_GC
// leave the first page to contain only segment info
// because otherwise we could need to revisit the first page frequently in
Expand Down Expand Up @@ -31185,6 +31252,7 @@ void gc_heap::thread_final_regions (bool compact_p)
else
{
start_region = get_free_region (gen_idx);
assert (start_region);
thread_start_region (gen, start_region);
dprintf (REGIONS_LOG, ("creating new gen%d at %Ix", gen_idx, heap_segment_mem (start_region)));
}
Expand Down
6 changes: 6 additions & 0 deletions src/coreclr/gc/gcpriv.h
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Original file line number Diff line number Diff line change
Expand Up @@ -4091,6 +4091,12 @@ class gc_heap
PER_HEAP_ISOLATED
size_t heap_hard_limit_oh[total_oh_count];

PER_HEAP_ISOLATED
size_t heap_hard_limit_for_heap;

PER_HEAP_ISOLATED
size_t heap_hard_limit_for_bookkeeping;

PER_HEAP_ISOLATED
CLRCriticalSection check_commit_cs;

Expand Down