Andy Wingo
1228e346fa
Fix semi-space collector for refactor
2022-10-03 15:37:01 +02:00
Andy Wingo
8a51117763
Rework pinning, prepare for conservative tracing
...
We don't need a pin bit: we just need to mark pinned objects before
evacuation starts. This way we can remove the stopping / marking race
so that we can always mark while stopping.
2022-08-22 21:11:30 +02:00
Andy Wingo
2199d5f48d
Excise struct gcobj
2022-08-16 23:21:16 +02:00
Andy Wingo
6ecf226570
More typesafety, more gc_ref
2022-08-16 22:48:46 +02:00
Andy Wingo
92b8f1e917
Add gc_ prefix to struct heap, struct mutator
2022-08-16 21:35:16 +02:00
Andy Wingo
b082f5f50d
Separate compilation!!!!!
2022-08-16 17:54:15 +02:00
Andy Wingo
fe9bdf6397
Separate out embedder API from mt-gcbench, quads
2022-08-16 16:09:36 +02:00
Andy Wingo
112f27b77b
Simplify GC attributes for the inline allocator
...
Don't require pulling in all of gc-api.h.
2022-08-16 16:00:06 +02:00
Andy Wingo
8a111256c6
Compile with -fvisibility=hidden; will be good for separate compilation
2022-08-16 12:04:56 +02:00
Andy Wingo
9e8940e59f
Get handles out of collectors
2022-08-16 11:53:32 +02:00
Andy Wingo
607585e7f0
Add whippet-inline.h
2022-08-16 10:25:23 +02:00
Andy Wingo
33aa5230da
Add bdw-inline.h
2022-08-15 18:30:42 +02:00
Andy Wingo
8f2f4f7c69
API-ify gc_print_stats; add semi-inline.h
2022-08-15 18:17:18 +02:00
Andy Wingo
a00c83878e
Inline post-allocation actions
2022-08-15 16:06:52 +02:00
Andy Wingo
a75842be90
Mostly implementation-independent inline allocation
...
This is a step towards separate compilation of the GC without losing
performance. Only remaining task is the write barrier.
2022-08-15 11:17:15 +02:00
Andy Wingo
4d8a7169d0
Add inline to gc-api.h
2022-08-14 09:18:21 +02:00
Andy Wingo
fb71c4c363
Separate tagging from collector
...
The collector now has an abstract interface onto the embedder. The
embedder has to supply some functionality, such as tracing and
forwarding. This is a pretty big change in terms of lines but it's
supposed to have no functional or performance change.
2022-08-12 16:44:38 +02:00
Andy Wingo
cacc28b577
Always add a header onto objects
...
We're targetting systems that need to be able to inspect the kind of an
object, so this information has to be somewhere. If it's out-of-line,
we might save memory, but we would lose locality. Concretely in Guile
the tag bits are in the object itself.
2022-08-09 16:14:47 +02:00
Andy Wingo
d8bcbf2d74
More API-ification
2022-08-09 11:35:31 +02:00
Andy Wingo
4ccb489869
Set fixed heap size, parallelism via explicit options
2022-08-09 11:21:02 +02:00
Andy Wingo
2e6dde66b3
Attempt to start creating a proper API
2022-08-09 09:49:51 +02:00
Andy Wingo
c824f17bd9
Rename gc-types.h to gc-api.h
2022-08-08 11:08:36 +02:00
Andy Wingo
67f9c89f2a
Use fragmentation_low_threshold for venerable_threshold
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This way fragmentation from venerable blocks doesn't cause the collector
to keep evacuating.
2022-08-04 11:32:06 +02:00
Andy Wingo
0450a282dd
Skip mostly-tenured blocks during sweep/allocate after minor GC
2022-08-04 09:04:27 +02:00
Andy Wingo
0fe13e1cab
Accelerate scanning of remembered set
2022-08-03 21:25:18 +02:00
Andy Wingo
47c07dd0eb
Fix embarassing ctz issue
2022-08-03 16:40:34 +02:00
Andy Wingo
8f6a2692ab
Update README
2022-08-03 12:13:25 +02:00
Andy Wingo
96b68095b7
Fix mark pattern updating for generational whippet
...
After a minor collection, we were erroneously failing to sweep dead
objects with the survivor tag.
2022-08-03 12:06:19 +02:00
Andy Wingo
0210a8caf0
Refactor out-of-memory detection
...
Firstly, we add a priority evacuation reserve to prioritize having a few
evacuation blocks on hand. Otherwise if we give them all to big
allocations first and we have a fragmented heap, we won't be able to
evacuate that fragmented heap to give more blocks to the large
allocations.
Secondly, we remove `enum gc_reason`. The issue is that with multiple
mutator threads, the precise thread triggering GC does not provide much
information. Instead we should make choices on how to collect based on
the state of the heap.
Finally, we move detection of out-of-memory inside the collector,
instead of the allocator.
Together, these changes let mt-gcbench (with fragmentation) operate in
smaller heaps.
2022-08-03 10:10:33 +02:00
Andy Wingo
1358d99abc
Fix yield calculation after evacuating collections
2022-08-02 22:15:13 +02:00
Andy Wingo
a4e1f55f37
Implement generational collection
...
Not really battle-tested but it seems to work. Need to implement
heuristics for when to do generational vs full-heap GC.
2022-08-02 15:37:02 +02:00
Andy Wingo
13b3bb5b24
Update barrier functions to also have the object being written
...
Also remove read barriers, as they were unused, and we have no plans to
use them.
2022-08-02 15:37:02 +02:00
Andy Wingo
7f405c929e
Initial live mask does not include young allocations
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After rotation, the young bit wasn't being included anyway. This just
improves the first collection.
2022-08-02 15:37:02 +02:00
Andy Wingo
1781c5aed4
Fix evacuation allocator to clear any holes
2022-08-02 15:36:59 +02:00
Andy Wingo
22a9cc87a0
Update TODO
2022-07-20 14:40:47 +02:00
Andy Wingo
279309b821
mt-gcbench allocates garbage between live data
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This obviously invalidates previous benchmark results; perhaps we should
make this optional.
2022-07-20 14:40:47 +02:00
Andy Wingo
d106f3ca71
Mutator collects evacuation target blocks
2022-07-20 14:40:47 +02:00
Andy Wingo
92b05a6310
Add implementation of parallel evacuation
2022-07-20 14:40:47 +02:00
Andy Wingo
4a9908bc4d
Refactor evacuation vs pinning support
...
Marking conservative roots in place effectively prohibits them from
being moved, and we need to trace the roots anyway to discover
conservative roots. No need therefore for a pin bit.
2022-07-20 14:40:47 +02:00
Andy Wingo
a16bb1833c
Add logic to compute evacuation candidate blocks
2022-07-20 14:40:47 +02:00
Andy Wingo
c7c8fa2d32
Refactor to add "block_list" type
2022-07-20 14:40:47 +02:00
Andy Wingo
a8214af467
Whippet reserves a bit in object kind for forwarding
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Tags without the bit are forwarding addresses.
2022-07-20 14:40:47 +02:00
Andy Wingo
8409383ee1
Refactor post-collection for mark space
2022-07-20 14:40:47 +02:00
Andy Wingo
69caead182
Add heuristics to choose when to compact or mark in place
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We can choose to compact (evacuate) or mark in place. What we choose
has some effects on how we mark.
2022-07-20 14:40:47 +02:00
Andy Wingo
09d2df1626
Compute GC yield as fraction of total heap size
2022-07-20 14:40:47 +02:00
Andy Wingo
c998f1cd5c
Measure fragmentation as fraction of total heap size
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This allows a relatively more fragmented mark space if the majority of
the heap is taken up by lospace.
2022-07-20 14:40:47 +02:00
Andy Wingo
7af8bb6bd0
Add machinery to disable ragged-stop marking
...
We'll need to disable the optimization that mutators mark their own
stacks once we support evacuation.
2022-07-20 14:40:47 +02:00
Andy Wingo
e4342f6c45
Add helper for yielding in a spinlock
2022-07-20 14:40:47 +02:00
Andy Wingo
52166fe286
Add gc_edge data structure
...
Less casting in user programs, and it's a step on the way to evacuation
in whippet.
2022-07-20 14:40:47 +02:00
Andy Wingo
808d365f4b
We identify empty blocks lazily now
2022-07-20 14:40:47 +02:00
