mirrors/mimalloc
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

fix decommit of huge pages

Browse Source
This commit is contained in:
Daan Leijen 2022-11-23 09:58:45 -08:00
parent e7dac7c405
commit a7bd9c08c8
2 changed files with 35 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
src/segment.c
View File

@ -1224,26 +1224,22 @@ static mi_page_t* mi_segment_huge_page_alloc(size_t size, size_t page_alignment,
mi_page_t* page = mi_segment_find_free(segment, tld);
mi_assert_internal(page != NULL);
if (page_alignment > 0) {
size_t psize;
size_t pre_size;
uint8_t* p = (uint8_t*)_mi_segment_page_start(segment, page, 0, &psize, &pre_size);
uint8_t* aligned_p = (uint8_t*)_mi_align_up((uintptr_t)p, page_alignment);
mi_assert_internal(_mi_is_aligned(aligned_p, page_alignment));
mi_assert_internal(psize - (aligned_p - p) >= size);
if (!segment->mem_is_pinned && page->is_committed) {
// decommit the part of the page that is unused; this can be quite large (close to MI_SEGMENT_SIZE)
uint8_t* decommit_start = p + sizeof(mi_block_t); // for the free list
ptrdiff_t decommit_size = aligned_p - decommit_start;
_mi_os_reset(decommit_start, decommit_size, os_tld->stats);
}
}
// for huge pages we initialize the xblock_size as we may
// overallocate to accommodate large alignments.
size_t psize;
_mi_segment_page_start(segment, page, 0, &psize, NULL);
uint8_t* start = _mi_segment_page_start(segment, page, 0, &psize, NULL);
page->xblock_size = (psize > MI_HUGE_BLOCK_SIZE ? MI_HUGE_BLOCK_SIZE : (uint32_t)psize);
// reset the part of the page that will not be used; this can be quite large (close to MI_SEGMENT_SIZE)
if (page_alignment > 0 && !segment->mem_is_pinned && page->is_committed) {
uint8_t* aligned_p = (uint8_t*)_mi_align_up((uintptr_t)start, page_alignment);
mi_assert_internal(_mi_is_aligned(aligned_p, page_alignment));
mi_assert_internal(psize - (aligned_p - start) >= size);
uint8_t* decommit_start = start + sizeof(mi_block_t); // for the free list
ptrdiff_t decommit_size = aligned_p - decommit_start;
_mi_os_reset(decommit_start, decommit_size, os_tld->stats); // do not decommit as it may be in a region
}
return page;
}
@ -1283,8 +1279,11 @@ void _mi_segment_huge_page_reset(mi_segment_t* segment, mi_page_t* page, mi_bloc
mi_assert_internal(segment == _mi_page_segment(page));
mi_assert_internal(page->used == 1); // this is called just before the free
mi_assert_internal(page->free == NULL);
const size_t bsize = mi_page_block_size(page);
_mi_os_reset(block + 1, bsize - sizeof(mi_block_t), &_mi_stats_main);
if (!segment->mem_is_pinned && page->is_committed) {
const size_t usize = mi_usable_size(block) - sizeof(mi_block_t);
uint8_t* p = (uint8_t*)block + sizeof(mi_block_t);
_mi_os_reset(p, usize, &_mi_stats_main);
}
}
#endif

22
test/main-override.cpp
View File

@ -34,23 +34,26 @@ static void various_tests();
static void test_mt_shutdown();
static void fail_aslr(); // issue #372
static void tsan_numa_test(); // issue #414
static void strdup_test(); // issue #445
static void strdup_test(); // issue #445
static void heap_thread_free_huge();
static void test_stl_allocators();
int main() {
mi_stats_reset(); // ignore earlier allocations
heap_thread_free_huge();
/*
heap_thread_free_large();
heap_no_delete();
heap_late_free();
padding_shrink();
various_tests();
tsan_numa_test();
strdup_test();
strdup_test();
test_stl_allocators();
test_mt_shutdown();
*/
//fail_aslr();
mi_stats_print(NULL);
return 0;
@ -235,6 +238,17 @@ static void heap_thread_free_large() {
}
}
static void heap_thread_free_huge_worker() {
mi_free(shared_p);
}
static void heap_thread_free_huge() {
for (int i = 0; i < 10; i++) {
shared_p = mi_malloc(1024 * 1024 * 1024);
auto t1 = std::thread(heap_thread_free_large_worker);
t1.join();
}
}
static void test_mt_shutdown()