Fix warmup shapes for corner cases (#136)

Co-authored-by: Karol Damaszke <kdamaszke@habana.ai>

router/client/src/client.rs

@@ -121,7 +121,12 @@ impl Client {
         };
 
         // get all possible prefill batch sizes
-        let max_prefill_batch_size: u32 = max_prefill_tokens / max_input_length;
+        let mut max_prefill_batch_size: u32 = max_prefill_tokens / max_input_length;
+        let max_decode_batch_size: u32 = match max_batch_size {
+            Some(max_batch_size) => max_batch_size as u32,
+            None => read_env_var("PREFILL_BATCH_BUCKET_SIZE", 8)
+        };
+        max_prefill_batch_size = cmp::min(max_prefill_batch_size, max_decode_batch_size);
         let prefill_bucket_size: u32 = read_env_var("PREFILL_BATCH_BUCKET_SIZE", 4);
         let batch_sizes: Vec<u32> = (prefill_bucket_size..max_prefill_batch_size+1).step_by(prefill_bucket_size as usize).collect();
 
@@ -142,13 +147,10 @@ impl Client {
             }
         }
 
-        // if max_batch_size is None, create two batches
-        let num_batches = max_batch_size.unwrap_or(2).min(2);
         let mut id_counter: u64 = 0;
         for shape in shapes.iter() {
-            // create two batches in order to trigger concatenate operation
+            let (batch_size, seq_length) = shape;
-            // in case decode bs=1 create one batch
+            let mut batches: Vec<Batch> = vec![
-            let batches: Vec<Batch> = vec![
                 self.create_warmup_batch(
                     *shape,
                     &mut id_counter,
@@ -156,9 +158,22 @@ impl Client {
                     max_total_tokens,
                     seq_bucket_size,
                     false,
-                );
+                )
-                num_batches
             ];
+            // if possible, create second batch in order to trigger concatenate operation
+            if *batch_size < max_decode_batch_size {
+                batches.push(
+                    self.create_warmup_batch(
+                        (1, *seq_length),
+                        &mut id_counter,
+                        max_input_length,
+                        max_total_tokens,
+                        seq_bucket_size,
+                        false,
+                    )
+                );
+            }
+
             let request = tonic::Request::new(WarmupRequest {
                 batches,
                 max_input_length,
@@ -168,7 +183,7 @@ impl Client {
             let _response = self.stub.warmup(request).await?.into_inner();
         }
 
-        //Send batches with deafult params to warm up Greedy search
+        // send batches with default params to warm up Greedy search
         let mut greedy_shapes: Vec<(u32, u32)> = Vec::with_capacity(batch_sizes.len());
         for batch_size in &batch_sizes {
             greedy_shapes.push((*batch_size, seq_bucket_size.clone()));
@@ -182,8 +197,7 @@ impl Client {
                     max_total_tokens,
                     seq_bucket_size,
                     true,
-                );
+                )
-                num_batches
             ];
             let request = tonic::Request::new(WarmupRequest {
                 batches,

server/text_generation_server/models/causal_lm.py

@@ -1114,6 +1114,8 @@ class CausalLM(Model):
 
         # if decode bs is 1 warmup ends here
         if len(batches) == 0:
+            while decode_batch is not None:
+                _, decode_batch, _ = self.generate_token([decode_batch])
             return
 
         # prefill