Rewrite GC page metadata for sweeping fast path #16632
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yuyichao
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| // Note that before marking or after sweeping there can be live | ||
| // (and young) cells in the page for `!has_marked`. | ||
| uint16_t has_marked: 1; | ||
| // Whether any cell was live and yound **before sweeping**. |
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Ooops, I must really like 'd' these days. I typed count as cound many times while working on this.
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Just fixed a stupid bug in the full collection heuristics I added that was causing a runtime regression (and possibly memory) and this should be ready now. I'd like to run this through the CI's a few more time to check. It'll also be nice if someone else could also verify the page metadata is valid. See here for the meanings of each bits and the motivation of the design can be found here. |
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Cool ! LGTM. That was smaller than I expected. We should still run a round of benchs because the heuristics are a little touchy. |
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* Delete `gc_bits` and `allocd` which are not enough to accurately record the necessary information. * Add `has_marked` and `has_young` to identify free pages and untouched pages. Fixes #15543
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This implements a slightly modified version of the page metadata part of the bit swapping generational GC (the part currently implemented is actually simpler due to not having to worry about the other gc bit...). @carnaval
gc_bitsandallocdin page metadata which are not enough to accuratelyrecord the necessary information.
has_markedandhas_youngto identify free pages and untouched pages.TODO:
Fixes #15543
Replaces #13993