OLD | NEW |
---|---|
1 /* | 1 /* |
2 * Copyright (C) 2013 Google Inc. All rights reserved. | 2 * Copyright (C) 2013 Google Inc. All rights reserved. |
3 * | 3 * |
4 * Redistribution and use in source and binary forms, with or without | 4 * Redistribution and use in source and binary forms, with or without |
5 * modification, are permitted provided that the following conditions are | 5 * modification, are permitted provided that the following conditions are |
6 * met: | 6 * met: |
7 * | 7 * |
8 * * Redistributions of source code must retain the above copyright | 8 * * Redistributions of source code must retain the above copyright |
9 * notice, this list of conditions and the following disclaimer. | 9 * notice, this list of conditions and the following disclaimer. |
10 * * Redistributions in binary form must reproduce the above | 10 * * Redistributions in binary form must reproduce the above |
(...skipping 506 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
517 RELEASE_ASSERT(bucket->numFullPages); | 517 RELEASE_ASSERT(bucket->numFullPages); |
518 // Not necessary but might help stop accidents. | 518 // Not necessary but might help stop accidents. |
519 page->nextPage = 0; | 519 page->nextPage = 0; |
520 } | 520 } |
521 } | 521 } |
522 | 522 |
523 bucket->activePagesHead = 0; | 523 bucket->activePagesHead = 0; |
524 return false; | 524 return false; |
525 } | 525 } |
526 | 526 |
527 static ALWAYS_INLINE size_t partitionDirectMapAvailableSize(PartitionPage* page) | |
Chris Evans
2014/03/05 07:57:04
This function seems a bit complicated, or at least
| |
528 { | |
529 // Return the size of the mapping, *not* including space where meta-data is | |
530 // stored, and *not* including one trailing inaccessible system page; IOW | |
531 // the size of the area available for the actual allocation. Some of the | |
532 // pages at the end of this memory range may have been decommitted and made | |
533 // inaccessible by a partitionReallocGeneric() call. | |
534 // | |
535 // The value of bucket->slotSize is size of the current allocation. | |
536 | |
537 PartitionBucket* bucket = page->bucket; | |
538 | |
539 ASSERT(partitionBucketIsDirectMapped(bucket)); | |
540 ASSERT(bucket != &PartitionRootBase::gPagedBucket); | |
541 | |
542 char* ptr = static_cast<char*>(partitionPageToPointer(page)); | |
543 char* endPtr = reinterpret_cast<char*>(bucket->freePagesHead) - kSystemPageS ize; | |
544 | |
545 size_t size = endPtr - ptr; | |
546 ASSERT(bucket->slotSize <= size); | |
547 return size; | |
548 } | |
549 | |
527 static ALWAYS_INLINE void* partitionDirectMap(PartitionRootBase* root, int flags , size_t size) | 550 static ALWAYS_INLINE void* partitionDirectMap(PartitionRootBase* root, int flags , size_t size) |
528 { | 551 { |
529 size = partitionDirectMapSize(size); | 552 size = partitionDirectMapSize(size); |
530 | 553 |
531 // Because we need to fake looking like a super page, We need to allocate | 554 // Because we need to fake looking like a super page, We need to allocate |
532 // a bunch of system pages more than "size": | 555 // a bunch of system pages more than "size": |
533 // - The first few system pages are the partition page in which the super | 556 // - The first few system pages are the partition page in which the super |
534 // page metadata is stored. We fault just one system page out of a partition | 557 // page metadata is stored. We fault just one system page out of a partition |
535 // page sized clump. | 558 // page sized clump. |
536 // - We add a trailing guard page. | 559 // - We add a trailing guard page. |
(...skipping 32 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
569 PartitionBucket* bucket = reinterpret_cast<PartitionBucket*>(reinterpret_cas t<char*>(page) + kPageMetadataSize); | 592 PartitionBucket* bucket = reinterpret_cast<PartitionBucket*>(reinterpret_cas t<char*>(page) + kPageMetadataSize); |
570 page->freelistHead = 0; | 593 page->freelistHead = 0; |
571 page->nextPage = 0; | 594 page->nextPage = 0; |
572 page->bucket = bucket; | 595 page->bucket = bucket; |
573 page->numAllocatedSlots = 1; | 596 page->numAllocatedSlots = 1; |
574 page->numUnprovisionedSlots = 0; | 597 page->numUnprovisionedSlots = 0; |
575 page->pageOffset = 0; | 598 page->pageOffset = 0; |
576 page->freeCacheIndex = 0; | 599 page->freeCacheIndex = 0; |
577 | 600 |
578 bucket->activePagesHead = 0; | 601 bucket->activePagesHead = 0; |
579 bucket->freePagesHead = 0; | 602 bucket->freePagesHead = reinterpret_cast<PartitionPage*>(ptr + mapSize); |
Chris Evans
2014/03/05 07:57:04
I'm not a huge fan of this.
For each direct mappi
Jens Widell
2014/03/05 08:11:43
I certainly wasn't either. :-)
| |
580 bucket->slotSize = size; | 603 bucket->slotSize = size; |
581 bucket->numSystemPagesPerSlotSpan = 0; | 604 bucket->numSystemPagesPerSlotSpan = 0; |
582 bucket->numFullPages = 0; | 605 bucket->numFullPages = 0; |
583 | 606 |
607 ASSERT(size <= partitionDirectMapAvailableSize(page)); | |
608 | |
584 return ret; | 609 return ret; |
585 } | 610 } |
586 | 611 |
587 static ALWAYS_INLINE void partitionDirectUnmap(PartitionPage* page) | 612 static ALWAYS_INLINE void partitionDirectUnmap(PartitionPage* page) |
588 { | 613 { |
589 size_t unmapSize = page->bucket->slotSize; | 614 size_t unmapSize = partitionDirectMapAvailableSize(page); |
615 | |
590 // Add on the size of the trailing guard page and preceeding partition | 616 // Add on the size of the trailing guard page and preceeding partition |
591 // page, then round up to allocation granularity. | 617 // page. |
592 unmapSize += kPartitionPageSize + kSystemPageSize; | 618 unmapSize += kPartitionPageSize + kSystemPageSize; |
593 unmapSize += kPageAllocationGranularityOffsetMask; | 619 |
594 unmapSize &= kPageAllocationGranularityBaseMask; | 620 ASSERT(!(unmapSize & kPageAllocationGranularityOffsetMask)); |
595 | 621 |
596 char* ptr = reinterpret_cast<char*>(partitionPageToPointer(page)); | 622 char* ptr = reinterpret_cast<char*>(partitionPageToPointer(page)); |
597 // Account for the mapping starting a partition page before the actual | 623 // Account for the mapping starting a partition page before the actual |
598 // allocation address. | 624 // allocation address. |
599 ptr -= kPartitionPageSize; | 625 ptr -= kPartitionPageSize; |
600 | 626 |
601 freePages(ptr, unmapSize); | 627 freePages(ptr, unmapSize); |
602 } | 628 } |
603 | 629 |
604 void* partitionAllocSlowPath(PartitionRootBase* root, int flags, size_t size, Pa rtitionBucket* bucket) | 630 void* partitionAllocSlowPath(PartitionRootBase* root, int flags, size_t size, Pa rtitionBucket* bucket) |
(...skipping 151 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
756 page->nextPage = bucket->activePagesHead; | 782 page->nextPage = bucket->activePagesHead; |
757 bucket->activePagesHead = page; | 783 bucket->activePagesHead = page; |
758 --bucket->numFullPages; | 784 --bucket->numFullPages; |
759 // Special case: for a partition page with just a single slot, it may | 785 // Special case: for a partition page with just a single slot, it may |
760 // now be empty and we want to run it through the empty logic. | 786 // now be empty and we want to run it through the empty logic. |
761 if (UNLIKELY(page->numAllocatedSlots == 0)) | 787 if (UNLIKELY(page->numAllocatedSlots == 0)) |
762 partitionFreeSlowPath(page); | 788 partitionFreeSlowPath(page); |
763 } | 789 } |
764 } | 790 } |
765 | 791 |
792 bool partitionReallocDirectMappedInPlace(PartitionRootGeneric* root, void* ptr, size_t newSize) | |
793 { | |
794 newSize = partitionCookieSizeAdjustAdd(newSize); | |
795 ASSERT(partitionDirectMapSize(newSize) == newSize); | |
Chris Evans
2014/03/05 07:57:04
I think we also need newSize to be a multiple of k
Jens Widell
2014/03/05 08:11:43
The value returned by partitionDirectMapSize(size)
| |
796 | |
797 char* realPtr = static_cast<char*>(partitionCookieFreePointerAdjust(ptr)); | |
798 PartitionPage* page = partitionPointerToPage(realPtr); | |
799 PartitionBucket* bucket = page->bucket; | |
800 | |
801 // bucket->slotSize is the current size of the allocation. | |
802 // bucket->freePagesHead points to the first system page beyond what we | |
803 // first allocated; we can grow the allocation up to that point. | |
804 | |
805 ASSERT(partitionBucketIsDirectMapped(bucket)); | |
806 ASSERT(newSize != bucket->slotSize); | |
807 | |
808 if (newSize < bucket->slotSize) { | |
809 // Shrink by decommitting unneeded pages and making them inaccessible. | |
810 // TODO: maybe refuse if the new size is too much smaller? | |
811 size_t decommitSize = bucket->slotSize - newSize; | |
812 decommitSystemPages(realPtr + newSize, decommitSize); | |
813 setSystemPagesInaccessible(realPtr + newSize, decommitSize); | |
814 } else if (newSize <= partitionDirectMapAvailableSize(page)) { | |
815 // Grow within the actually allocated memory. Just need to make the | |
816 // pages accessible again. | |
817 size_t recommitSize = newSize - bucket->slotSize; | |
818 setSystemPagesAccessible(realPtr + bucket->slotSize, recommitSize); | |
819 | |
820 #ifndef NDEBUG | |
821 memset(realPtr + bucket->slotSize, kUninitializedByte, recommitSize); | |
822 #endif | |
823 } else { | |
824 // We can't perform the realloc in-place. | |
Chris Evans
2014/03/05 07:57:04
I think we can fill in this branch in the future (
| |
825 return false; | |
826 } | |
827 | |
828 #ifndef NDEBUG | |
829 // Write a new trailing cookie. | |
830 partitionCookieWriteValue(realPtr + newSize - kCookieSize); | |
831 #endif | |
832 | |
833 bucket->slotSize = newSize; | |
834 return true; | |
835 } | |
836 | |
766 void* partitionReallocGeneric(PartitionRootGeneric* root, void* ptr, size_t newS ize) | 837 void* partitionReallocGeneric(PartitionRootGeneric* root, void* ptr, size_t newS ize) |
767 { | 838 { |
768 #if defined(MEMORY_TOOL_REPLACES_ALLOCATOR) | 839 #if defined(MEMORY_TOOL_REPLACES_ALLOCATOR) |
769 return realloc(ptr, newSize); | 840 return realloc(ptr, newSize); |
770 #else | 841 #else |
771 if (UNLIKELY(!ptr)) | 842 if (UNLIKELY(!ptr)) |
772 return partitionAllocGeneric(root, newSize); | 843 return partitionAllocGeneric(root, newSize); |
773 if (UNLIKELY(!newSize)) { | 844 if (UNLIKELY(!newSize)) { |
774 partitionFreeGeneric(root, ptr); | 845 partitionFreeGeneric(root, ptr); |
775 return 0; | 846 return 0; |
776 } | 847 } |
Chris Evans
2014/03/05 07:57:04
Can we just put a no nonsense RELEASE_ASSERT here?
| |
777 | 848 |
778 ASSERT(partitionPointerIsValid(partitionCookieFreePointerAdjust(ptr))); | 849 ASSERT(partitionPointerIsValid(partitionCookieFreePointerAdjust(ptr))); |
779 | 850 |
780 size_t actualNewSize = partitionAllocActualSize(root, newSize); | 851 size_t actualNewSize = partitionAllocActualSize(root, newSize); |
781 size_t actualOldSize = partitionAllocGetSize(ptr); | 852 size_t actualOldSize = partitionAllocGetSize(ptr); |
782 | 853 |
783 // TODO: note that tcmalloc will "ignore" a downsizing realloc() unless the | 854 // TODO: note that tcmalloc will "ignore" a downsizing realloc() unless the |
784 // new size is a significant percentage smaller. We could do the same if we | 855 // new size is a significant percentage smaller. We could do the same if we |
785 // determine it is a win. | 856 // determine it is a win. |
786 if (actualNewSize == actualOldSize) { | 857 if (actualNewSize == actualOldSize) { |
787 // Trying to allocate a block of size newSize would give us a block of | 858 // Trying to allocate a block of size newSize would give us a block of |
788 // the same size as the one we've already got, so no point in doing | 859 // the same size as the one we've already got, so no point in doing |
789 // anything here. | 860 // anything here. |
790 // TODO: for an upsize or downsize on a direct mapped allocation, we | |
791 // should really try and resize it in-place. | |
792 return ptr; | 861 return ptr; |
793 } | 862 } |
794 | 863 |
864 if (partitionSizeIsDirectMapped(actualOldSize) && partitionSizeIsDirectMappe d(actualNewSize)) { | |
Chris Evans
2014/03/05 07:57:04
I actually think we might want to relax the second
Jens Widell
2014/03/05 08:11:43
The reason I didn't do that was to avoid having an
| |
865 // We may be able to perform the realloc in place by changing the | |
866 // accessibility of memory pages and, if reducing the size, decommitting | |
867 // them. | |
868 if (partitionReallocDirectMappedInPlace(root, ptr, actualNewSize)) | |
869 return ptr; | |
870 } | |
871 | |
795 // This realloc cannot be resized in-place. Sadness. | 872 // This realloc cannot be resized in-place. Sadness. |
796 void* ret = partitionAllocGeneric(root, newSize); | 873 void* ret = partitionAllocGeneric(root, newSize); |
797 size_t copySize = actualOldSize; | 874 size_t copySize = actualOldSize; |
798 if (newSize < copySize) | 875 if (newSize < copySize) |
799 copySize = newSize; | 876 copySize = newSize; |
800 | 877 |
801 memcpy(ret, ptr, copySize); | 878 memcpy(ret, ptr, copySize); |
802 partitionFreeGeneric(root, ptr); | 879 partitionFreeGeneric(root, ptr); |
803 return ret; | 880 return ret; |
804 #endif | 881 #endif |
(...skipping 50 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
855 printf("total live: %zu bytes\n", totalLive); | 932 printf("total live: %zu bytes\n", totalLive); |
856 printf("total resident: %zu bytes\n", totalResident); | 933 printf("total resident: %zu bytes\n", totalResident); |
857 printf("total freeable: %zu bytes\n", totalFreeable); | 934 printf("total freeable: %zu bytes\n", totalFreeable); |
858 fflush(stdout); | 935 fflush(stdout); |
859 } | 936 } |
860 | 937 |
861 #endif // !NDEBUG | 938 #endif // !NDEBUG |
862 | 939 |
863 } // namespace WTF | 940 } // namespace WTF |
864 | 941 |
OLD | NEW |