add partition helpers

dalle_mini/partitions.py

@@ -0,0 +1,69 @@
+import re
+
+from flax.core.frozen_dict import freeze
+from flax.traverse_util import flatten_dict, unflatten_dict
+from jax.experimental import PartitionSpec as P
+
+
+# utils adapted from https://gitihub.com/google-research/google-research/blob/master/flax_models/t5x/partitions.py
+# Sentinels
+_unmatched = object()
+
+# For specifying empty leaf dict `{}`
+empty_dict = object()
+
+
+def _match(qs, ks):
+    """Return True if regexes in qs match any window of strings in tuple ks."""
+    # compile regexes and force complete match
+    qts = tuple(map(lambda x: re.compile(x + "$"), qs))
+    for i in range(len(ks) - len(qs) + 1):
+        matches = [x.match(y) for x, y in zip(qts, ks[i:])]
+        if matches and all(matches):
+            return True
+    return False
+
+
+def _replacement_rules(rules):
+    def replace(key, val):
+        for rule, replacement in rules:
+            if _match(rule, key):
+                return replacement
+        return val
+
+    return replace
+
+
+def _get_partition_rules():
+    return [
+        # embeddings
+        ((r"embed_positions", "embedding"), P("mp", None)),
+        ((r"embed_tokens", "embedding"), P("mp", None)),
+        # self-attention
+        ((r"self_attn", "(q_proj|k_proj|v_proj)", "kernel"), P(None, "mp")),
+        ((r"self_attn", "out_proj", "kernel"), P("mp", None)),
+        # enc-dec attention
+        ((r"encoder_attn", "(q_proj|k_proj|v_proj)", "kernel"), P(None, "mp")),
+        ((r"encoder_attn", "out_proj", "kernel"), P("mp", None)),
+        # FFN
+        ((r"fc1", "kernel"), P(None, "mp")),
+        ((r"fc2", "kernel"), P("mp", None)),
+        # layer norms
+        ((r"layernorm_embedding", "(bias|scale)"), None),
+        ((r"self_attn_layer_norm", "(bias|scale)"), None),
+        ((r"encoder_attn_layer_norm", "(bias|scale)"), None),
+        ((r"final_layer_norm", "(bias|scale)"), None),
+        ((r"lm_head", "kernel"), P(None, "mp")),
+    ]
+
+
+def set_partitions(in_dict):
+    rules = _get_partition_rules()
+    replace = _replacement_rules(rules)
+    initd = {k: _unmatched for k in flatten_dict(in_dict)}
+    result = {k: replace(k, v) for k, v in initd.items()}
+    for k, v in result.items():
+        if v == _unmatched:
+            print(k)
+    assert _unmatched not in result.values(), "Incomplete partition spec."
+    return freeze(unflatten_dict(result))