add flashdecoding-ipex

Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>

Dockerfile_intel

@@ -224,7 +224,7 @@ COPY --from=builder /usr/src/target/release-opt/text-generation-router /usr/loca
 COPY --from=builder /usr/src/target/release-opt/text-generation-launcher /usr/local/bin/text-generation-launcher
 
 FROM ${PLATFORM} AS final
-ENV ATTENTION=flashdecoding
+ENV ATTENTION=flashdecoding-ipex
 ENV PREFIX_CACHING=1
 ENV PREFILL_CHUNKING=1
 ENV CUDA_GRAPHS=0

launcher/src/main.rs

@@ -144,7 +144,9 @@ fn resolve_attention(config: &Option<Config>, lora_adapters: &Option<String>) ->
             }
         }
 
-        let fallback_attention = if matches!(compute_capability, Some((major, _)) if major < 8) {
+        let fallback_attention = if compute_capability.is_none()
+            || matches!(compute_capability, Some((major, _)) if major < 8)
+        {
             "paged"
         } else {
             "flashdecoding"

server/text_generation_server/layers/attention/ipex.py

@@ -31,7 +31,7 @@ def attention(
     out = torch.empty_like(query)
 
     # We do not need to check window_size_left (not supported) here, so it is already checked ahead of time at model load.
-    if ATTENTION == "flashdecoding":
+    if ATTENTION == "flashdecoding-ipex":
         ipex.llm.modules.PagedAttention.flash_attn_varlen_func(
             out,
             query.contiguous() if query.device.type == "xpu" else query,
@@ -84,7 +84,7 @@ def paged_attention(
 
     out = torch.empty_like(query)
 
-    if ATTENTION == "flashdecoding":
+    if ATTENTION == "flashdecoding-ipex":
         ipex.llm.modules.PagedAttention.flash_attn_varlen_func(
             out,
             query.contiguous() if query.device.type == "xpu" else query,

server/text_generation_server/layers/attention/kv_cache.py

@@ -66,8 +66,8 @@ class KVCache:
         else:
             x = BLOCK_SIZE // element_size
 
-        if ATTENTION in {"flashdecoding", "flashinfer"} and not (
-            SYSTEM == "ipex" and device == torch.device("cpu")
+        if ATTENTION in {"flashdecoding", "flashinfer"} or (
+            ATTENTION == "flashdecoding-ipex" and device.type == "xpu"
         ):
             self.kv_cache = (
                 torch.empty(
@@ -82,6 +82,7 @@ class KVCache:
                 ),
             )
         elif SYSTEM == "ipex" and device == torch.device("cpu"):
+            # ipex cpu flashdecoding kernel and paged attention kernel share same layout
             self.kv_cache = (
                 torch.empty(
                     (num_blocks, num_heads, BLOCK_SIZE, head_size),
@@ -176,9 +177,7 @@ class KVCache:
                     scalar=True,
                 )[0]
 
-        if ATTENTION in {"flashdecoding", "flashinfer"} and not (
-            SYSTEM == "ipex" and key.device == torch.device("cpu")
-        ):
+        if ATTENTION in {"flashdecoding", "flashinfer"}:
             key = key.to(key_cache.dtype)
             value = value.to(value_cache.dtype)
             if key_cache.dtype in {torch.float8_e4m3fn, torch.float8_e5m2}:
@@ -191,6 +190,12 @@ class KVCache:
             shape = key_cache.shape
             key_cache.view(-1, shape[-2], shape[-1])[slots] = key
             value_cache.view(-1, shape[-2], shape[-1])[slots] = value
+        elif ATTENTION == "flashdecoding-ipex" and key.device.type == "xpu":
+            import intel_extension_for_pytorch as ipex
+
+            ipex.llm.modules.PagedAttention.reshape_and_cache_flash(
+                key, value, key_cache, value_cache, slots
+            )
         else:
             paged_reshape_and_cache(key, value, key_cache, value_cache, slots)
 

server/text_generation_server/models/globals.py

@@ -4,7 +4,6 @@ from loguru import logger
 from typing import Dict, Optional
 
 from text_generation_server.utils.log import log_master
-from text_generation_server.utils.import_utils import SYSTEM
 
 REQUEST_LOGPROBS = os.getenv("REQUEST_LOGPROBS", "0").lower() in {"1", "true"}
 ATTENTION = os.environ["ATTENTION"]
@@ -15,13 +14,17 @@ PREFIX_CACHING = os.environ["PREFIX_CACHING"].lower() in {
 }
 PREFILL_CHUNKING = os.getenv("PREFILL_CHUNKING", "1").lower() in {"1", "true"}
 log_master(logger.info, f"Using prefix caching = {PREFIX_CACHING}")
-_expected = {"paged", "flashdecoding", "flashinfer"}
+_expected = {"paged", "flashdecoding", "flashdecoding-ipex", "flashinfer"}
 assert (
     ATTENTION in _expected
 ), f"Attention is not valid {ATTENTION}, expected {_expected}"
 log_master(logger.info, f"Using Attention = {ATTENTION}")
 
-if PREFIX_CACHING and ATTENTION not in {"flashinfer", "flashdecoding"}:
+if PREFIX_CACHING and ATTENTION not in {
+    "flashinfer",
+    "flashdecoding",
+    "flashdecoding-ipex",
+}:
     raise RuntimeError("Prefix caching is only supported with flashinfer")
 
 MEM_POOL = torch.cuda.graph_pool_handle() if torch.cuda.is_available() else None
@@ -33,12 +36,11 @@ assert TGI_WIGGLE_ROOM < 1
 # This is overridden by the cli
 BLOCK_SIZE: int
 if ATTENTION == "flashdecoding":
-    if SYSTEM == "ipex":
-        BLOCK_SIZE = 64
-    else:
     BLOCK_SIZE = 256
 elif ATTENTION == "flashinfer":
     BLOCK_SIZE = 1
+elif ATTENTION == "flashdecoding-ipex":
+    BLOCK_SIZE = 64
 else:
     BLOCK_SIZE = 16
 

server/text_generation_server/models/model.py

@@ -79,10 +79,13 @@ class Model(ABC):
                 "Prefill chunking will be turned off",
             )
             support_chunking = False
-        if ATTENTION not in ["flashinfer", "flashdecoding"] and support_chunking:
+        if (
+            ATTENTION not in ["flashinfer", "flashdecoding", "flashdecoding-ipex"]
+            and support_chunking
+        ):
             log_master(
                 logger.warning,
-                "Prefill chunking is only supported with `flashinfer` or `flashdecoding` attention types.",
+                "Prefill chunking is only supported with `flashinfer` or `flashdecoding` or `flashdecoding-ipex` attention types.",
             )
             support_chunking = False