Clearing all cards for free regions

[cshung]

This change fixed two issues associated with card table clearing.

When we return a region to the free region list, we can clear the cards.

If we use heap_segment_mem (region), this will always be 0x20 bytes after the start of the page. The align_on_card logic inside clear_card_for_addresses will skip resetting the card for the first page.

Before these fixes, #76801 is always failing with *card_word == 1. This is because the initial card (i.e. the least significant bit) cannot be reset because of the alignment.

After these fixes, the test case no longer fails locally after running for 4 hours in a loop.

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Issue Details

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This change fixed two issues associated with card table clearing.

When we return a region to the free region list, we can clear the cards.

If we use heap_segment_mem (region), this will always be 0x20 bytes after the start of the page. The align_on_card logic inside clear_card_for_addresses will skip resetting the card for the first page.

Before these fixes, #76801 is always failing with *card_word == 1. This is because the initial card (i.e. the least significant bit) cannot be reset because of the alignment.

After these fixes, the test case is still failing, but it is no longer failing for the same reason, in particular, *card_word != 1 when it fails.

Author:	cshung
Assignees:	cshung
Labels:	area-GC-coreclr
Milestone:	-

[Maoni0]

as we chatted about, let's change allocated to reserved.