diff --git a/mmtk/Cargo.lock b/mmtk/Cargo.lock
index af8ccf7..dbc986c 100644
--- a/mmtk/Cargo.lock
+++ b/mmtk/Cargo.lock
@@ -100,38 +100,38 @@ checksum = "812e12b5285cc515a9c72a5c1d3b6d46a19dac5acfef5265968c166106e31dd3"
 
 [[package]]
 name = "built"
-version = "0.7.7"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "56ed6191a7e78c36abdb16ab65341eefd73d64d303fffccdbb00d51e4205967b"
+checksum = "f4ad8f11f288f48ca24471bbd51ac257aaeaaa07adae295591266b792902ae64"
 dependencies = [
  "git2",
 ]
 
 [[package]]
 name = "bytemuck"
-version = "1.23.1"
+version = "1.24.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c76a5792e44e4abe34d3abf15636779261d45a7450612059293d1d2cfc63422"
+checksum = "1fbdf580320f38b612e485521afda1ee26d10cc9884efaaa750d383e13e3c5f4"
 dependencies = [
  "bytemuck_derive",
 ]
 
 [[package]]
 name = "bytemuck_derive"
-version = "1.8.1"
+version = "1.10.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3fa76293b4f7bb636ab88fd78228235b5248b4d05cc589aed610f954af5d7c7a"
+checksum = "f9abbd1bc6865053c427f7198e6af43bfdedc55ab791faed4fbd361d789575ff"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.111",
+ "syn 2.0.114",
 ]
 
 [[package]]
 name = "cc"
-version = "1.2.49"
+version = "1.2.52"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90583009037521a116abf44494efecd645ba48b6622457080f080b85544e2215"
+checksum = "cd4932aefd12402b36c60956a4fe0035421f544799057659ff86f923657aada3"
 dependencies = [
  "find-msvc-tools",
  "jobserver",
@@ -151,12 +151,6 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b05b61dc5112cbb17e4b6cd61790d9845d13888356391624cbe7e41efeac1e75"
 
-[[package]]
-name = "core-foundation-sys"
-version = "0.8.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "773648b94d0e5d620f64f280777445740e61fe701025087ec8b57f45c791888b"
-
 [[package]]
 name = "crossbeam"
 version = "0.8.4"
@@ -221,7 +215,18 @@ checksum = "780eb241654bf097afb00fc5f054a09b687dad862e485fdcf8399bb056565370"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.111",
+ "syn 2.0.114",
+]
+
+[[package]]
+name = "displaydoc"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97369cbbc041bc366949bc74d34658d6cda5621039731c6310521892a3a20ae0"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -253,7 +258,7 @@ checksum = "f282cfdfe92516eb26c2af8589c274c7c17681f5ecc03c18255fe741c6aa64eb"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.111",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -281,9 +286,9 @@ dependencies = [
 
 [[package]]
 name = "find-msvc-tools"
-version = "0.1.5"
+version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3a3076410a55c90011c298b04d0cfa770b00fa04e1e3c97d3f6c9de105a03844"
+checksum = "f449e6c6c08c865631d4890cfacf252b3d396c9bcc83adb6623cdb02a8336c41"
 
 [[package]]
 name = "form_urlencoded"
@@ -332,34 +337,105 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc0fef456e4baa96da950455cd02c081ca953b141298e41db3fc7e36b1da849c"
 
 [[package]]
-name = "idna"
-version = "1.1.0"
+name = "icu_collections"
+version = "2.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b0875f23caa03898994f6ddc501886a45c7d3d62d04d2d90788d47be1b1e4de"
+checksum = "4c6b649701667bbe825c3b7e6388cb521c23d88644678e83c0c4d0a621a34b43"
 dependencies = [
- "idna_adapter",
+ "displaydoc",
+ "potential_utf",
+ "yoke",
+ "zerofrom",
+ "zerovec",
+]
+
+[[package]]
+name = "icu_locale_core"
+version = "2.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "edba7861004dd3714265b4db54a3c390e880ab658fec5f7db895fae2046b5bb6"
+dependencies = [
+ "displaydoc",
+ "litemap",
+ "tinystr",
+ "writeable",
+ "zerovec",
+]
+
+[[package]]
+name = "icu_normalizer"
+version = "2.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f6c8828b67bf8908d82127b2054ea1b4427ff0230ee9141c54251934ab1b599"
+dependencies = [
+ "icu_collections",
+ "icu_normalizer_data",
+ "icu_properties",
+ "icu_provider",
  "smallvec",
- "utf8_iter",
+ "zerovec",
 ]
 
 [[package]]
-name = "idna_adapter"
-version = "1.1.0"
+name = "icu_normalizer_data"
+version = "2.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "279259b0ac81c89d11c290495fdcfa96ea3643b7df311c138b6fe8ca5237f0f8"
+checksum = "7aedcccd01fc5fe81e6b489c15b247b8b0690feb23304303a9e560f37efc560a"
+
+[[package]]
+name = "icu_properties"
+version = "2.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "020bfc02fe870ec3a66d93e677ccca0562506e5872c650f893269e08615d74ec"
 dependencies = [
- "idna_mapping",
- "unicode-bidi",
- "unicode-normalization",
+ "icu_collections",
+ "icu_locale_core",
+ "icu_properties_data",
+ "icu_provider",
+ "zerotrie",
+ "zerovec",
 ]
 
 [[package]]
-name = "idna_mapping"
+name = "icu_properties_data"
+version = "2.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "616c294cf8d725c6afcd8f55abc17c56464ef6211f9ed59cccffe534129c77af"
+
+[[package]]
+name = "icu_provider"
+version = "2.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85962cf0ce02e1e0a629cc34e7ca3e373ce20dda4c4d7294bbd0bf1fdb59e614"
+dependencies = [
+ "displaydoc",
+ "icu_locale_core",
+ "writeable",
+ "yoke",
+ "zerofrom",
+ "zerotrie",
+ "zerovec",
+]
+
+[[package]]
+name = "idna"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "11c13906586a4b339310541a274dd927aff6fcbb5b8e3af90634c4b31681c792"
+checksum = "3b0875f23caa03898994f6ddc501886a45c7d3d62d04d2d90788d47be1b1e4de"
+dependencies = [
+ "idna_adapter",
+ "smallvec",
+ "utf8_iter",
+]
+
+[[package]]
+name = "idna_adapter"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3acae9609540aa318d1bc588455225fb2085b9ed0c4f6bd0d9d5bcd86f1a0344"
 dependencies = [
- "unicode-joining-type",
+ "icu_normalizer",
+ "icu_properties",
 ]
 
 [[package]]
@@ -390,9 +466,9 @@ dependencies = [
 
 [[package]]
 name = "jiff"
-version = "0.2.16"
+version = "0.2.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "49cce2b81f2098e7e3efc35bc2e0a6b7abec9d34128283d7a26fa8f32a6dbb35"
+checksum = "e67e8da4c49d6d9909fe03361f9b620f58898859f5c7aded68351e85e71ecf50"
 dependencies = [
  "jiff-static",
  "log",
@@ -403,13 +479,13 @@ dependencies = [
 
 [[package]]
 name = "jiff-static"
-version = "0.2.16"
+version = "0.2.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "980af8b43c3ad5d8d349ace167ec8170839f753a42d233ba19e08afe1850fa69"
+checksum = "e0c84ee7f197eca9a86c6fd6cb771e55eb991632f15f2bc3ca6ec838929e6e78"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.111",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -430,9 +506,9 @@ checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 
 [[package]]
 name = "libc"
-version = "0.2.178"
+version = "0.2.180"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37c93d8daa9d8a012fd8ab92f088405fb202ea0b6ab73ee2482ae66af4f42091"
+checksum = "bcc35a38544a891a5f7c865aca548a982ccb3b8650a5b06d0fd33a10283c56fc"
 
 [[package]]
 name = "libgit2-sys"
@@ -458,6 +534,12 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "litemap"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6373607a59f0be73a39b6fe456b8192fcc3585f602af20751600e974dd455e77"
+
 [[package]]
 name = "lock_api"
 version = "0.4.14"
@@ -491,14 +573,13 @@ dependencies = [
 [[package]]
 name = "mmtk"
 version = "0.31.0"
-source = "git+https://github.com/mmtk/mmtk-core.git?rev=e30d0a0866fe66d352eb09eb7f9e9466dc649172#e30d0a0866fe66d352eb09eb7f9e9466dc649172"
+source = "git+https://github.com/mmtk/mmtk-core.git?rev=45a5f881f37c97aa42e06790fe54a10a53b2eb45#45a5f881f37c97aa42e06790fe54a10a53b2eb45"
 dependencies = [
  "atomic",
  "atomic-traits",
  "atomic_refcell",
  "built",
  "bytemuck",
- "bytemuck_derive",
  "cfg-if",
  "crossbeam",
  "delegate",
@@ -516,7 +597,6 @@ dependencies = [
  "num_cpus",
  "portable-atomic",
  "probe",
- "rayon-core",
  "regex",
  "rustversion",
  "spin",
@@ -529,12 +609,12 @@ dependencies = [
 [[package]]
 name = "mmtk-macros"
 version = "0.31.0"
-source = "git+https://github.com/mmtk/mmtk-core.git?rev=e30d0a0866fe66d352eb09eb7f9e9466dc649172#e30d0a0866fe66d352eb09eb7f9e9466dc649172"
+source = "git+https://github.com/mmtk/mmtk-core.git?rev=45a5f881f37c97aa42e06790fe54a10a53b2eb45#45a5f881f37c97aa42e06790fe54a10a53b2eb45"
 dependencies = [
  "proc-macro-error",
  "proc-macro2",
  "quote",
- "syn 2.0.111",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -553,9 +633,9 @@ dependencies = [
 
 [[package]]
 name = "ntapi"
-version = "0.4.1"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e8a3895c6391c39d7fe7ebc444a87eb2991b2a0bc718fdabd071eec617fc68e4"
+checksum = "c70f219e21142367c70c0b30c6a9e3a14d55b4d12a204d897fbec83a0363f081"
 dependencies = [
  "winapi",
 ]
@@ -579,6 +659,25 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "objc2-core-foundation"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a180dd8642fa45cdb7dd721cd4c11b1cadd4929ce112ebd8b9f5803cc79d536"
+dependencies = [
+ "bitflags",
+]
+
+[[package]]
+name = "objc2-io-kit"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "33fafba39597d6dc1fb709123dfa8289d39406734be322956a69f0931c73bb15"
+dependencies = [
+ "libc",
+ "objc2-core-foundation",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.21.3"
@@ -605,9 +704,9 @@ checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"
 
 [[package]]
 name = "portable-atomic"
-version = "1.11.1"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f84267b20a16ea918e43c6a88433c2d54fa145c92a811b5b047ccbe153674483"
+checksum = "f89776e4d69bb58bc6993e99ffa1d11f228b839984854c7daeb5d37f87cbe950"
 
 [[package]]
 name = "portable-atomic-util"
@@ -618,6 +717,15 @@ dependencies = [
  "portable-atomic",
 ]
 
+[[package]]
+name = "potential_utf"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b73949432f5e2a09657003c25bca5e19a0e9c84f8058ca374f49e0ebe605af77"
+dependencies = [
+ "zerovec",
+]
+
 [[package]]
 name = "probe"
 version = "0.5.2"
@@ -650,18 +758,18 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.103"
+version = "1.0.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ee95bc4ef87b8d5ba32e8b7714ccc834865276eab0aed5c9958d00ec45f49e8"
+checksum = "535d180e0ecab6268a3e718bb9fd44db66bbbc256257165fc699dadf70d16fe7"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.42"
+version = "1.0.43"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a338cc41d27e6cc6dce6cefc13a0729dfbb81c262b1f519331575dd80ef3067f"
+checksum = "dc74d9a594b72ae6656596548f56f667211f8a97b3d4c3d467150794690dc40a"
 dependencies = [
  "proc-macro2",
 ]
@@ -672,26 +780,6 @@ version = "5.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "69cdb34c158ceb288df11e18b4bd39de994f6657d83847bdffdbd7f346754b0f"
 
-[[package]]
-name = "rayon"
-version = "1.10.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b418a60154510ca1a002a752ca9714984e21e4241e804d32555251faf8b78ffa"
-dependencies = [
- "either",
- "rayon-core",
-]
-
-[[package]]
-name = "rayon-core"
-version = "1.12.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1465873a3dfdaa8ae7cb14b4383657caab0b3e8a0aa9ae8e04b044854c8dfce2"
-dependencies = [
- "crossbeam-deque",
- "crossbeam-utils",
-]
-
 [[package]]
 name = "regex"
 version = "1.12.2"
@@ -755,7 +843,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
 dependencies = [
  "serde_core",
- "serde_derive",
 ]
 
 [[package]]
@@ -775,7 +862,7 @@ checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.111",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -792,13 +879,19 @@ checksum = "67b1b7a3b5fe4f1376887184045fcf45c69e92af734b7aaddc05fb777b6fbd03"
 
 [[package]]
 name = "spin"
-version = "0.9.8"
+version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
+checksum = "d5fe4ccb98d9c292d56fec89a5e07da7fc4cf0dc11e156b41793132775d3e591"
 dependencies = [
  "lock_api",
 ]
 
+[[package]]
+name = "stable_deref_trait"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ce2be8dc25455e1f91df71bfa12ad37d7af1092ae736f3a6cd0e37bc7810596"
+
 [[package]]
 name = "static_assertions"
 version = "1.1.0"
@@ -820,7 +913,7 @@ dependencies = [
  "heck",
  "proc-macro2",
  "quote",
- "syn 2.0.111",
+ "syn 2.0.114",
 ]
 
 [[package]]
@@ -835,76 +928,61 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.111"
+version = "2.0.114"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "390cc9a294ab71bdb1aa2e99d13be9c753cd2d7bd6560c77118597410c4d2e87"
+checksum = "d4d107df263a3013ef9b1879b0df87d706ff80f65a86ea879bd9c31f9b307c2a"
 dependencies = [
  "proc-macro2",
  "quote",
  "unicode-ident",
 ]
 
+[[package]]
+name = "synstructure"
+version = "0.13.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "728a70f3dbaf5bab7f0c4b1ac8d7ae5ea60a4b5549c8a5914361c99147a709d2"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.114",
+]
+
 [[package]]
 name = "sysinfo"
-version = "0.33.1"
+version = "0.36.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fc858248ea01b66f19d8e8a6d55f41deaf91e9d495246fd01368d99935c6c01"
+checksum = "252800745060e7b9ffb7b2badbd8b31cfa4aa2e61af879d0a3bf2a317c20217d"
 dependencies = [
- "core-foundation-sys",
  "libc",
  "memchr",
  "ntapi",
- "rayon",
+ "objc2-core-foundation",
+ "objc2-io-kit",
  "windows",
 ]
 
 [[package]]
-name = "tinyvec"
-version = "1.10.0"
+name = "tinystr"
+version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bfa5fdc3bce6191a1dbc8c02d5c8bffcf557bafa17c124c5264a458f1b0613fa"
+checksum = "42d3e9c45c09de15d06dd8acf5f4e0e399e85927b7f00711024eb7ae10fa4869"
 dependencies = [
- "tinyvec_macros",
+ "displaydoc",
+ "zerovec",
 ]
 
-[[package]]
-name = "tinyvec_macros"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
-
-[[package]]
-name = "unicode-bidi"
-version = "0.3.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c1cb5db39152898a79168971543b1cb5020dff7fe43c8dc468b0885f5e29df5"
-
 [[package]]
 name = "unicode-ident"
 version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
 
-[[package]]
-name = "unicode-joining-type"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d8d00a78170970967fdb83f9d49b92f959ab2bb829186b113e4f4604ad98e180"
-
-[[package]]
-name = "unicode-normalization"
-version = "0.1.25"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5fd4f6878c9cb28d874b009da9e8d183b5abc80117c40bbd187a1fde336be6e8"
-dependencies = [
- "tinyvec",
-]
-
 [[package]]
 name = "url"
-version = "2.5.7"
+version = "2.5.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08bc136a29a3d1758e07a9cca267be308aeebf5cfd5a10f3f67ab2097683ef5b"
+checksum = "ff67a8a4397373c3ef660812acab3268222035010ab8680ec4215f38ba3d0eed"
 dependencies = [
  "form_urlencoded",
  "idna",
@@ -969,61 +1047,110 @@ checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
 [[package]]
 name = "windows"
-version = "0.57.0"
+version = "0.61.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9babd3a767a4c1aef6900409f85f5d53ce2544ccdfaa86dad48c91782c6d6893"
+dependencies = [
+ "windows-collections",
+ "windows-core",
+ "windows-future",
+ "windows-link 0.1.3",
+ "windows-numerics",
+]
+
+[[package]]
+name = "windows-collections"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "12342cb4d8e3b046f3d80effd474a7a02447231330ef77d71daa6fbc40681143"
+checksum = "3beeceb5e5cfd9eb1d76b381630e82c4241ccd0d27f1a39ed41b2760b255c5e8"
 dependencies = [
  "windows-core",
- "windows-targets",
 ]
 
 [[package]]
 name = "windows-core"
-version = "0.57.0"
+version = "0.61.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d2ed2439a290666cd67ecce2b0ffaad89c2a56b976b736e6ece670297897832d"
+checksum = "c0fdd3ddb90610c7638aa2b3a3ab2904fb9e5cdbecc643ddb3647212781c4ae3"
 dependencies = [
  "windows-implement",
  "windows-interface",
+ "windows-link 0.1.3",
  "windows-result",
- "windows-targets",
+ "windows-strings",
+]
+
+[[package]]
+name = "windows-future"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc6a41e98427b19fe4b73c550f060b59fa592d7d686537eebf9385621bfbad8e"
+dependencies = [
+ "windows-core",
+ "windows-link 0.1.3",
+ "windows-threading",
 ]
 
 [[package]]
 name = "windows-implement"
-version = "0.57.0"
+version = "0.60.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9107ddc059d5b6fbfbffdfa7a7fe3e22a226def0b2608f72e9d552763d3e1ad7"
+checksum = "053e2e040ab57b9dc951b72c264860db7eb3b0200ba345b4e4c3b14f67855ddf"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.111",
+ "syn 2.0.114",
 ]
 
 [[package]]
 name = "windows-interface"
-version = "0.57.0"
+version = "0.59.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "29bee4b38ea3cde66011baa44dba677c432a78593e202392d1e9070cf2a7fca7"
+checksum = "3f316c4a2570ba26bbec722032c4099d8c8bc095efccdc15688708623367e358"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.111",
+ "syn 2.0.114",
 ]
 
+[[package]]
+name = "windows-link"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e6ad25900d524eaabdbbb96d20b4311e1e7ae1699af4fb28c17ae66c80d798a"
+
 [[package]]
 name = "windows-link"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
 
+[[package]]
+name = "windows-numerics"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9150af68066c4c5c07ddc0ce30421554771e528bde427614c61038bc2c92c2b1"
+dependencies = [
+ "windows-core",
+ "windows-link 0.1.3",
+]
+
 [[package]]
 name = "windows-result"
-version = "0.1.2"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e383302e8ec8515204254685643de10811af0ed97ea37210dc26fb0032647f8"
+checksum = "56f42bd332cc6c8eac5af113fc0c1fd6a8fd2aa08a0119358686e5160d0586c6"
 dependencies = [
- "windows-targets",
+ "windows-link 0.1.3",
+]
+
+[[package]]
+name = "windows-strings"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56e6c93f3a0c3b36176cb1327a4958a0353d5d166c2a35cb268ace15e91d3b57"
+dependencies = [
+ "windows-link 0.1.3",
 ]
 
 [[package]]
@@ -1032,75 +1159,103 @@ version = "0.61.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
 dependencies = [
- "windows-link",
+ "windows-link 0.2.1",
 ]
 
 [[package]]
-name = "windows-targets"
-version = "0.52.6"
+name = "windows-threading"
+version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
+checksum = "b66463ad2e0ea3bbf808b7f1d371311c80e115c0b71d60efc142cafbcfb057a6"
 dependencies = [
- "windows_aarch64_gnullvm",
- "windows_aarch64_msvc",
- "windows_i686_gnu",
- "windows_i686_gnullvm",
- "windows_i686_msvc",
- "windows_x86_64_gnu",
- "windows_x86_64_gnullvm",
- "windows_x86_64_msvc",
+ "windows-link 0.1.3",
 ]
 
 [[package]]
-name = "windows_aarch64_gnullvm"
-version = "0.52.6"
+name = "wit-bindgen"
+version = "0.46.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
+checksum = "f17a85883d4e6d00e8a97c586de764dabcc06133f7f1d55dce5cdc070ad7fe59"
 
 [[package]]
-name = "windows_aarch64_msvc"
-version = "0.52.6"
+name = "writeable"
+version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
+checksum = "9edde0db4769d2dc68579893f2306b26c6ecfbe0ef499b013d731b7b9247e0b9"
 
 [[package]]
-name = "windows_i686_gnu"
-version = "0.52.6"
+name = "yoke"
+version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
+checksum = "72d6e5c6afb84d73944e5cedb052c4680d5657337201555f9f2a16b7406d4954"
+dependencies = [
+ "stable_deref_trait",
+ "yoke-derive",
+ "zerofrom",
+]
 
 [[package]]
-name = "windows_i686_gnullvm"
-version = "0.52.6"
+name = "yoke-derive"
+version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
+checksum = "b659052874eb698efe5b9e8cf382204678a0086ebf46982b79d6ca3182927e5d"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.114",
+ "synstructure",
+]
 
 [[package]]
-name = "windows_i686_msvc"
-version = "0.52.6"
+name = "zerofrom"
+version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
+checksum = "50cc42e0333e05660c3587f3bf9d0478688e15d870fab3346451ce7f8c9fbea5"
+dependencies = [
+ "zerofrom-derive",
+]
 
 [[package]]
-name = "windows_x86_64_gnu"
-version = "0.52.6"
+name = "zerofrom-derive"
+version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
+checksum = "d71e5d6e06ab090c67b5e44993ec16b72dcbaabc526db883a360057678b48502"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.114",
+ "synstructure",
+]
 
 [[package]]
-name = "windows_x86_64_gnullvm"
-version = "0.52.6"
+name = "zerotrie"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
+checksum = "2a59c17a5562d507e4b54960e8569ebee33bee890c70aa3fe7b97e85a9fd7851"
+dependencies = [
+ "displaydoc",
+ "yoke",
+ "zerofrom",
+]
 
 [[package]]
-name = "windows_x86_64_msvc"
-version = "0.52.6"
+name = "zerovec"
+version = "0.11.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
+checksum = "6c28719294829477f525be0186d13efa9a3c602f7ec202ca9e353d310fb9a002"
+dependencies = [
+ "yoke",
+ "zerofrom",
+ "zerovec-derive",
+]
 
 [[package]]
-name = "wit-bindgen"
-version = "0.46.0"
+name = "zerovec-derive"
+version = "0.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f17a85883d4e6d00e8a97c586de764dabcc06133f7f1d55dce5cdc070ad7fe59"
+checksum = "eadce39539ca5cb3985590102671f2567e659fca9666581ad3411d59207951f3"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.114",
+]
diff --git a/mmtk/Cargo.toml b/mmtk/Cargo.toml
index 51b3560..ceca093 100644
--- a/mmtk/Cargo.toml
+++ b/mmtk/Cargo.toml
@@ -12,7 +12,7 @@ edition = "2021"
 # Metadata for the Ruby repository
 [package.metadata.ci-repos.ruby]
 repo = "mmtk/ruby" # This is used by actions/checkout, so the format is "owner/repo", not URL.
-rev = "42eae121557de55e5ef6af3525c9253da7298fca"
+rev = "db7b82e33081066233281cdfcc0b7321b29703af"
 
 [lib]
 name = "mmtk_ruby"
@@ -37,7 +37,7 @@ features = ["is_mmtk_object", "object_pinning", "sticky_immix_non_moving_nursery
 
 # Uncomment the following lines to use mmtk-core from the official repository.
 git = "https://github.com/mmtk/mmtk-core.git"
-rev = "e30d0a0866fe66d352eb09eb7f9e9466dc649172"
+rev = "45a5f881f37c97aa42e06790fe54a10a53b2eb45"
 
 # Uncomment the following line to use mmtk-core from a local repository.
 #path = "../../mmtk-core"
diff --git a/mmtk/src/abi.rs b/mmtk/src/abi.rs
index 15fad3e..94cbe0e 100644
--- a/mmtk/src/abi.rs
+++ b/mmtk/src/abi.rs
@@ -17,9 +17,6 @@ pub const MMTK_WEAK_CONCURRENT_SET_KIND_GLOBAL_SYMBOLS: u8 = 1;
 
 pub(crate) const RUBY_IMMEDIATE_MASK: usize = 0x07;
 
-#[allow(non_upper_case_globals)] // Match Ruby definition
-pub(crate) const Qundef: VALUE = VALUE(0x24);
-
 #[repr(transparent)]
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
 pub struct VALUE(pub usize);
@@ -419,6 +416,8 @@ pub struct RubyUpcalls {
     // Memory protection for code memory
     pub before_updating_jit_code: extern "C" fn(),
     pub after_updating_jit_code: extern "C" fn(),
+    // Weak reference processing
+    pub handle_weak_references: extern "C" fn(object: ObjectReference, is_moving: bool),
 }
 
 unsafe impl Sync for RubyUpcalls {}
diff --git a/mmtk/src/api.rs b/mmtk/src/api.rs
index 106fe15..787ea71 100644
--- a/mmtk/src/api.rs
+++ b/mmtk/src/api.rs
@@ -9,7 +9,6 @@ use crate::abi;
 use crate::abi::HiddenHeader;
 use crate::abi::RawVecOfObjRef;
 use crate::abi::RubyBindingOptions;
-use crate::abi::VALUE;
 use crate::binding;
 use crate::binding::RubyBinding;
 use crate::mmtk;
@@ -424,6 +423,6 @@ pub extern "C" fn mmtk_current_gc_is_nursery() -> bool {
 }
 
 #[no_mangle]
-pub extern "C" fn mmtk_discover_weak_field(field: *mut VALUE) {
-    crate::binding().weak_proc.discover_weak_field(field)
+pub extern "C" fn mmtk_declare_weak_references(obj: ObjectReference) {
+    crate::binding().weak_proc.declare_weak_references(obj)
 }
diff --git a/mmtk/src/weak_proc.rs b/mmtk/src/weak_proc.rs
index ea5ab1c..dfdd7b0 100644
--- a/mmtk/src/weak_proc.rs
+++ b/mmtk/src/weak_proc.rs
@@ -2,12 +2,12 @@ use std::sync::Mutex;
 
 use mmtk::{
     scheduler::{GCWork, GCWorker, WorkBucketStage},
-    util::{Address, ObjectReference},
+    util::ObjectReference,
     vm::ObjectTracerContext,
 };
 
 use crate::{
-    abi::{self, GCThreadTLS, Qundef, VALUE},
+    abi::{self, GCThreadTLS},
     extra_assert, is_mmtk_object_safe, upcalls, Ruby,
 };
 
@@ -27,15 +27,14 @@ pub enum WeakConcurrentSetKind {
     GlobalSymbols = abi::MMTK_WEAK_CONCURRENT_SET_KIND_GLOBAL_SYMBOLS,
 }
 
-pub type FieldType = *mut VALUE;
-
 pub struct WeakProcessor {
     /// Objects that needs `obj_free` called when dying.
     /// If it is a bottleneck, replace it with a lock-free data structure,
     /// or add candidates in batch.
     obj_free_candidates: Mutex<Vec<ObjectReference>>,
-    /// Weak fields discovered during the current GC.
-    weak_fields: Mutex<Vec<FieldType>>,
+    /// Objects that contain weak fields.
+    /// They are registered when such objects are allocated.
+    objects_with_weak_fields: Mutex<Vec<ObjectReference>>,
 }
 
 impl Default for WeakProcessor {
@@ -48,7 +47,7 @@ impl WeakProcessor {
     pub fn new() -> Self {
         Self {
             obj_free_candidates: Mutex::new(Vec::new()),
-            weak_fields: Default::default(),
+            objects_with_weak_fields: Default::default(),
         }
     }
 
@@ -75,26 +74,23 @@ impl WeakProcessor {
         std::mem::take(obj_free_candidates.as_mut())
     }
 
-    pub fn clear_weak_fields(&self) {
-        let mut weak_fields = self
-            .weak_fields
-            .try_lock()
-            .expect("Should not have contention.");
-        weak_fields.clear();
-    }
-
-    pub fn discover_weak_field(&self, field: FieldType) {
-        let mut weak_fields = self.weak_fields.lock().unwrap();
-        weak_fields.push(field);
-        trace!("Pushed weak field {field:?}");
+    pub fn declare_weak_references(&self, object: ObjectReference) {
+        let mut objects_with_weak_fields = self.objects_with_weak_fields.lock().unwrap();
+        objects_with_weak_fields.push(object);
+        trace!("Pushed object with weak fields {object}");
     }
 
-    pub fn get_all_weak_fields(&self) -> Vec<FieldType> {
-        let mut weak_fields = self
-            .weak_fields
+    pub fn get_all_objects_with_weak_fields(&self) -> Vec<ObjectReference> {
+        let mut objects_with_weak_fields = self
+            .objects_with_weak_fields
             .try_lock()
             .expect("Should not have contention.");
-        std::mem::take(&mut weak_fields)
+        std::mem::take(&mut objects_with_weak_fields)
+    }
+
+    pub fn re_add_objects_with_weak_fields(&self, objects: &[ObjectReference]) {
+        let mut objects_with_weak_fields = self.objects_with_weak_fields.lock().unwrap();
+        objects_with_weak_fields.extend_from_slice(objects);
     }
 
     pub fn process_weak_stuff(
@@ -115,7 +111,7 @@ impl WeakProcessor {
             Box::new(UpdateCCRefinementTable) as _,
             // END: Weak tables
             Box::new(UpdateWbUnprotectedObjectsList) as _,
-            Box::new(UpdateWeakFields) as _,
+            Box::new(ProcessWeakReferences) as _,
         ]);
 
         if SPECIALIZE_FSTRING_TABLE_PROCESSING {
@@ -346,48 +342,80 @@ impl Forwardable for ObjectReference {
     }
 }
 
-struct UpdateWeakFields;
+struct ProcessWeakReferences;
 
-impl GCWork<Ruby> for UpdateWeakFields {
-    fn do_work(&mut self, _worker: &mut GCWorker<Ruby>, _mmtk: &'static mmtk::MMTK<Ruby>) {
-        let weak_fields = crate::binding().weak_proc.get_all_weak_fields();
+impl GCWork<Ruby> for ProcessWeakReferences {
+    fn do_work(&mut self, worker: &mut GCWorker<Ruby>, _mmtk: &'static mmtk::MMTK<Ruby>) {
+        let is_moving_gc = crate::mmtk().get_plan().current_gc_may_move_object();
 
-        let num_fields = weak_fields.len();
-        let mut live = 0usize;
-        let mut forwarded = 0usize;
+        let objects_with_weak_fields = crate::binding()
+            .weak_proc
+            .get_all_objects_with_weak_fields();
 
-        debug!("Updating {num_fields} weak fields...");
+        let num_objects = objects_with_weak_fields.len();
+        let mut live = 0usize;
 
-        for field in weak_fields {
-            let old_value = unsafe { *field };
-            trace!("  Visiting weak field {field:?} -> {old_value:?}");
+        debug!("Processing {num_objects} objects with weak fields...");
 
-            if old_value.is_special_const() {
-                continue;
-            }
+        let gc_tls = unsafe { GCThreadTLS::from_vwt_check(worker.tls) };
 
-            let addr = unsafe { Address::from_usize(old_value.0) };
-            if !addr.is_mapped() {
-                panic!("Field {field:?} value {addr} points to unmapped area");
-            }
-            let Some(old_objref) = mmtk::memory_manager::is_mmtk_object(addr) else {
-                panic!("Field {field:?} value {addr} is an invalid object reference");
-            };
+        let mut live_objects = vec![];
 
-            if old_objref.is_reachable() {
+        for old_object in objects_with_weak_fields {
+            trace!("  Object with weak fields: {old_object}");
+            if old_object.is_reachable() {
+                trace!("    Object {old_object} is live");
                 live += 1;
-                if let Some(new_objref) = old_objref.get_forwarded_object() {
-                    forwarded += 1;
-                    let new_value = VALUE::from(new_objref);
-                    trace!("    Updated weak field {field:?} to {new_value:?}");
-                    unsafe { *field = new_value };
-                }
-            } else {
-                unsafe { *field = Qundef };
+
+                // Forward old_object if it is moved.
+                let object = if let Some(new_object) = old_object.get_forwarded_object() {
+                    trace!("    Object is moved: {old_object} -> {new_object}");
+                    new_object
+                } else {
+                    old_object
+                };
+
+                // We bind the rb_gc_location method to `ObjectReference::get_forwarded_object`
+                // because we are forwarding references in objects that have weak references.  We
+                // don't trace them.
+                let visit_object = |_worker, target_object: ObjectReference, pin: bool| {
+                    trace!(
+                        "Forwarding edge: {} -> {}{}",
+                        object,
+                        target_object,
+                        if pin { " pin" } else { "" }
+                    );
+                    extra_assert!(!pin, "Should not pin when forwarding reference.");
+                    extra_assert!(
+                        is_mmtk_object_safe(target_object.to_raw_address()),
+                        "Destination is not an MMTk object. Src: {object} dst: {target_object}"
+                    );
+                    if let Some(forwarded_target) = target_object.get_forwarded_object() {
+                        trace!(
+                            "  Forwarded target {} -> {}",
+                            target_object,
+                            forwarded_target
+                        );
+                        forwarded_target
+                    } else {
+                        target_object
+                    }
+                };
+                gc_tls
+                    .object_closure
+                    .set_temporarily_and_run_code(visit_object, || {
+                        (upcalls().handle_weak_references)(object, is_moving_gc);
+                    });
+
+                live_objects.push(object);
             }
         }
 
-        debug!("Updated {num_fields} weak fields.  {live} live, {forwarded} forwarded.");
-        probe!(mmtk_ruby, update_weak_fields, num_fields, live, forwarded);
+        crate::binding()
+            .weak_proc
+            .re_add_objects_with_weak_fields(&live_objects);
+
+        debug!("Processed {num_objects} objects with weak fields.  {live} live.");
+        probe!(mmtk_ruby, process_weak_references, num_objects, live);
     }
 }