[FIX] Remove hardcoded seq len (meta-pytorch#497)

Co-authored-by: Felipe Mello <[email protected]>

Author: felipemello1

.meta/mast/qwen3_14b_mast.yaml

@@ -61,7 +61,7 @@ trainer:
     warmup_steps: 1
   training:
     local_batch_size: ${local_batch_size}
-    seq_len: 2048
+    seq_len: ${sum:${max_req_tokens},${max_res_tokens}}  # seq_len >= max_req_tokens + max_res_tokens
     max_norm: 1.0
     steps: 1000000
     dtype: bfloat16
@@ -106,6 +106,7 @@ ref_model:
     flavor: 14B
     hf_assets_path: /mnt/wsfuse/teamforge/hf/qwen3_14b
   training:
+    seq_len: ${trainer.training.seq_len}
     dtype: bfloat16
     gc_freq: 1
   compile:

.meta/mast/qwen3_1_7b_mast.yaml

@@ -62,7 +62,7 @@ trainer:
     warmup_steps: 1
   training:
     local_batch_size: ${local_batch_size}
-    seq_len: 2048
+    seq_len: ${sum:${max_req_tokens},${max_res_tokens}}  # seq_len >= max_req_tokens + max_res_tokens
     max_norm: 1.0
     steps: 1000000
     dtype: bfloat16
@@ -108,6 +108,7 @@ ref_model:
     hf_assets_path: /mnt/wsfuse/teamforge/hf/qwen3_1.7b
     # hf_assets_path: hf://${model}
   training:
+    seq_len: ${trainer.training.seq_len}
     dtype: bfloat16
     gc_freq: 1
   compile:

.meta/mast/qwen3_32b_mast.yaml

@@ -61,7 +61,7 @@ trainer:
     warmup_steps: 1
   training:
     local_batch_size: ${local_batch_size}
-    seq_len: 2048
+    seq_len: ${sum:${max_req_tokens},${max_res_tokens}}  # seq_len >= max_req_tokens + max_res_tokens
     max_norm: 1.0
     steps: 1000000
     dtype: bfloat16
@@ -106,6 +106,7 @@ ref_model:
     flavor: 32B
     hf_assets_path: /mnt/wsfuse/teamforge/hf/qwen3_32b
   training:
+    seq_len: ${trainer.training.seq_len}
     dtype: bfloat16
     gc_freq: 1
   compile:

.meta/mast/qwen3_4b_mast.yaml

@@ -62,7 +62,7 @@ trainer:
     warmup_steps: 1
   training:
     local_batch_size: ${local_batch_size}
-    seq_len: 2048
+    seq_len: ${sum:${max_req_tokens},${max_res_tokens}}  # seq_len >= max_req_tokens + max_res_tokens
     max_norm: 1.0
     steps: 1000000
     dtype: bfloat16
@@ -108,6 +108,7 @@ ref_model:
     hf_assets_path: /mnt/wsfuse/teamforge/hf/qwen3_4b
     # hf_assets_path: hf://${model}
   training:
+    seq_len: ${trainer.training.seq_len}
     dtype: bfloat16
     gc_freq: 1
   compile:

.meta/mast/qwen3_8b_mast.yaml

@@ -61,7 +61,7 @@ trainer:
     warmup_steps: 1
   training:
     local_batch_size: ${local_batch_size}
-    seq_len: 2048
+    seq_len: ${sum:${max_req_tokens},${max_res_tokens}}  # seq_len >= max_req_tokens + max_res_tokens
     max_norm: 1.0
     steps: 1000000
     dtype: bfloat16
@@ -106,6 +106,7 @@ ref_model:
     flavor: 8B
     hf_assets_path: /mnt/wsfuse/teamforge/hf/qwen3_8b
   training:
+    seq_len: ${trainer.training.seq_len}
     dtype: bfloat16
     gc_freq: 1
   compile:

apps/grpo/qwen3_1_7b.yaml

@@ -4,8 +4,8 @@
 # Global configuration
 group_size: 8
 local_batch_size: 16 # per-device batch size
-max_req_tokens: 512
-max_res_tokens: 512
+max_req_tokens: 1024
+max_res_tokens: 1024
 model: "Qwen/Qwen3-1.7B"
 off_by_n: 1 # Off by one by default
 
@@ -57,7 +57,7 @@ trainer:
     warmup_steps: 1
   training:
     local_batch_size: ${local_batch_size}
-    seq_len: 2048
+    seq_len: ${sum:${max_req_tokens},${max_res_tokens}}  # seq_len >= max_req_tokens + max_res_tokens
     max_norm: 1.0
     steps: 1000000
     dtype: bfloat16

apps/grpo/qwen3_32b.yaml

@@ -60,7 +60,7 @@ trainer:
     warmup_steps: 1
   training:
     local_batch_size: ${local_batch_size}
-    seq_len: 2048
+    seq_len: ${sum:${max_req_tokens},${max_res_tokens}}  # seq_len >= max_req_tokens + max_res_tokens
     max_norm: 1.0
     steps: 1000000
     dtype: bfloat16

apps/grpo/qwen3_8b.yaml

@@ -4,8 +4,8 @@
 # Global configuration
 group_size: 8
 local_batch_size: 16 # per-device batch size
-max_req_tokens: 512
-max_res_tokens: 512
+max_req_tokens: 1024
+max_res_tokens: 1024
 model: "Qwen/Qwen3-8B"
 off_by_n: 1 # Off by one by default
 
@@ -53,7 +53,7 @@ trainer:
     warmup_steps: 1
   training:
     local_batch_size: ${local_batch_size}
-    seq_len: 2048
+    seq_len: ${sum:${max_req_tokens},${max_res_tokens}}  # seq_len >= max_req_tokens + max_res_tokens
     max_norm: 1.0
     steps: 1000000
     dtype: bfloat16

src/forge/util/config.py

@@ -15,6 +15,9 @@
 
 from omegaconf import DictConfig, OmegaConf
 
+# Add support for summing lists of numbers, e.g. ${sum:${max_req_tokens},${max_res_tokens}}
+OmegaConf.register_new_resolver("sum", lambda *args: sum(args), replace=True)
+
 
 def _has_component(node: Any) -> bool:
     """Check if a node has a _component_ field."""

tests/integration_tests/fixtures/qwen3_1_7b_no_tp.yaml

@@ -34,7 +34,7 @@ trainer:
     warmup_steps: 1
   training:
     local_batch_size: ${batch_size}
-    seq_len: 2048
+    seq_len: ${sum:${max_req_tokens},${max_res_tokens}}  # seq_len >= max_req_tokens + max_res_tokens
     max_norm: 1.0
     steps: 1000000
     dtype: bfloat16