try fix tgs agitate

dipu/torch_dipu/csrc_dipu/runtime/core/allocator/DIPUAsyncResourcePool.h

@@ -9,8 +9,6 @@
 
 namespace dipu {
 
-constexpr size_t kMaxAsyncResourcePoolLength = 8;
-
 template <class T>
 class AsyncResourcePool {
  public:

dipu/torch_dipu/csrc_dipu/runtime/core/allocator/DIPUCachingAllocator.cpp

@@ -1,4 +1,4 @@
 // Copyright (c) 2023, DeepLink.
 
 #include "DIPUCachingAllocator.h"
 
@@ -18,6 +18,15 @@
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
 std::mutex DIPURawDeviceAllocator::mutex_;
 
+size_t kMaxAsyncResourcePoolLength = [](){
+  size_t maxAsyncResourcePoolLength = 8;
+  const char* env = std::getenv("DIPU_MAX_ASYNC_RESOURCE_POOL_LENGTH");
+  if (env != nullptr) {
+    maxAsyncResourcePoolLength = std::atoi(env);
+  }
+  return maxAsyncResourcePoolLength;
+}();
+
 namespace {
 
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)

dipu/torch_dipu/csrc_dipu/runtime/core/allocator/DIPUCachingAllocator.h

@@ -13,6 +13,8 @@ namespace dipu {
 
 constexpr size_t kDefaultMermoryAlignment = 512;
 
+extern size_t kMaxAsyncResourcePoolLength;
+
 class MemoryAlignmentStrategy {
   size_t kBytesAlign = kDefaultMermoryAlignment;
   size_t alpha = 1;  // reserved