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better alignment for large and huge pages inside a segment

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This commit is contained in:
daan 2019-09-04 18:42:37 -07:00
parent 3bbc047ba6
commit e73982c4cf
2 changed files with 17 additions and 17 deletions
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2
src/alloc-aligned.c
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@ -46,7 +46,7 @@ static void* mi_heap_malloc_zero_aligned_at(mi_heap_t* heap, size_t size, size_t
uintptr_t adjust = alignment - (((uintptr_t)p + offset) % alignment);
mi_assert_internal(adjust % sizeof(uintptr_t) == 0);
void* aligned_p = (adjust == alignment ? p : (void*)((uintptr_t)p + adjust));
if (aligned_p != p) mi_page_set_has_aligned(_mi_ptr_page(p), true);
if (aligned_p != p) mi_page_set_has_aligned(_mi_ptr_page(p), true);
mi_assert_internal(((uintptr_t)aligned_p + offset) % alignment == 0);
mi_assert_internal( p == _mi_page_ptr_unalign(_mi_ptr_segment(aligned_p),_mi_ptr_page(aligned_p),aligned_p) );
return aligned_p;

32
src/segment.c
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@ -151,19 +151,19 @@ uint8_t* _mi_segment_page_start(const mi_segment_t* segment, const mi_page_t* pa
size_t psize = (segment->page_kind == MI_PAGE_HUGE ? segment->segment_size : (size_t)1 << segment->page_shift);
uint8_t* p = (uint8_t*)segment + page->segment_idx*psize;
if (page->segment_idx == 0) {
// the first page starts after the segment info (and possible guard page)
p += segment->segment_info_size;
psize -= segment->segment_info_size;
// for small and medium objects, ensure the page start is aligned with the block size (PR#66 by kickunderscore)
if (block_size > 0 && segment->page_kind <= MI_PAGE_MEDIUM) {
size_t adjust = block_size - ((uintptr_t)p % block_size);
if (adjust < block_size) {
p += adjust;
psize -= adjust;
}
mi_assert_internal((uintptr_t)p % block_size == 0);
}
if (page->segment_idx == 0) {
// the first page starts after the segment info (and possible guard page)
p += segment->segment_info_size;
psize -= segment->segment_info_size;
// for small and medium objects, ensure the page start is aligned with the block size (PR#66 by kickunderscore)
if (block_size > 0 && segment->page_kind <= MI_PAGE_MEDIUM) {
size_t adjust = block_size - ((uintptr_t)p % block_size);
if (adjust < block_size) {
p += adjust;
psize -= adjust;
}
mi_assert_internal((uintptr_t)p % block_size == 0);
}
}
long secure = mi_option_get(mi_option_secure);
if (secure > 1 || (secure == 1 && page->segment_idx == segment->capacity - 1)) {
@ -186,18 +186,18 @@ static size_t mi_segment_size(size_t capacity, size_t required, size_t* pre_size
capacity = MI_SMALL_PAGES_PER_SEGMENT;
}
*/
size_t minsize = sizeof(mi_segment_t) + ((capacity - 1) * sizeof(mi_page_t)) + 16 /* padding */;
const size_t minsize = sizeof(mi_segment_t) + ((capacity - 1) * sizeof(mi_page_t)) + 16 /* padding */;
size_t guardsize = 0;
size_t isize = 0;
if (!mi_option_is_enabled(mi_option_secure)) {
// normally no guard pages
isize = _mi_align_up(minsize, (16 > MI_MAX_ALIGN_SIZE ? 16 : MI_MAX_ALIGN_SIZE));
isize = _mi_align_up(minsize, 16 * MI_MAX_ALIGN_SIZE);
}
else {
// in secure mode, we set up a protected page in between the segment info
// and the page data (and one at the end of the segment)
size_t page_size = _mi_os_page_size();
const size_t page_size = _mi_os_page_size();
isize = _mi_align_up(minsize, page_size);
guardsize = page_size;
required = _mi_align_up(required, page_size);