diff --git a/include/ylt/coro_io/ibverbs/ib_io.hpp b/include/ylt/coro_io/ibverbs/ib_io.hpp
index 7b36a40e1..493681630 100644
--- a/include/ylt/coro_io/ibverbs/ib_io.hpp
+++ b/include/ylt/coro_io/ibverbs/ib_io.hpp
@@ -170,7 +170,6 @@ async_simple::coro::
       is_canceled = true;
     }
     if (is_canceled) [[unlikely]] {
-      co_await coro_io::dispatch(ib_socket.get_executor());
       ib_socket.close();
       co_return std::pair{std::make_error_code(std::errc::operation_canceled),
                           std::size_t{0}};
@@ -256,11 +255,9 @@ inline void reset_buffer(std::vector<ibv_sge>& buffer, std::size_t read_size) {
 
 template <ib_socket_t::io_type io, typename Buffer>
 async_simple::coro::Lazy<std::pair<std::error_code, std::size_t>>
-async_io_split(coro_io::ib_socket_t& ib_socket, Buffer&& raw_buffer,
-               bool read_some = false) {
+async_io_split_impl(coro_io::ib_socket_t& ib_socket, Buffer&& raw_buffer,
+                    bool read_some) {
   if (!ib_socket.is_open()) {
-    co_await coro_io::dispatch(
-        ib_socket.get_coro_executor()->get_asio_executor());
     co_return std::pair{std::make_error_code(std::errc::not_connected),
                         std::size_t{0}};
   }
@@ -268,8 +265,6 @@ async_io_split(coro_io::ib_socket_t& ib_socket, Buffer&& raw_buffer,
   make_sge(sge_list, raw_buffer);
   std::span<ibv_sge> sge_span = sge_list;
   if (sge_span.size() == 0) [[unlikely]] {
-    co_await coro_io::dispatch(
-        ib_socket.get_coro_executor()->get_asio_executor());
     co_return std::pair{std::error_code{}, std::size_t{0}};
   }
 
@@ -278,8 +273,6 @@ async_io_split(coro_io::ib_socket_t& ib_socket, Buffer&& raw_buffer,
   uint32_t max_size = ib_socket.get_buffer_size();
   std::size_t io_completed_size = consume_buffer(ib_socket, sge_span);
   if (sge_span.empty()) {
-    co_await coro_io::dispatch(
-        ib_socket.get_coro_executor()->get_asio_executor());
     co_return std::pair{std::error_code{}, io_completed_size};
   }
 
@@ -379,7 +372,6 @@ async_io_split(coro_io::ib_socket_t& ib_socket, Buffer&& raw_buffer,
         is_canceled = true;
       }
       if (is_canceled) [[unlikely]] {
-        co_await coro_io::dispatch(ib_socket.get_executor());
         ib_socket.close();
         co_return std::pair{std::make_error_code(std::errc::operation_canceled),
                             std::size_t{0}};
@@ -393,6 +385,19 @@ async_io_split(coro_io::ib_socket_t& ib_socket, Buffer&& raw_buffer,
   co_return std::pair{ec, io_completed_size};
 }
 
+template <ib_socket_t::io_type io, typename Buffer>
+async_simple::coro::Lazy<std::pair<std::error_code, std::size_t>>
+async_io_split(coro_io::ib_socket_t& ib_socket, Buffer&& raw_buffer,
+               bool read_some = false) {
+  auto ret = co_await async_io_split_impl<io>(
+      ib_socket, std::forward<Buffer>(raw_buffer), read_some);
+  if (!ib_socket.get_executor().running_in_this_thread()) [[unlikely]] {
+    // switch to io_thread
+    co_await dispatch(ib_socket.get_executor());
+  }
+  co_return ret;
+}
+
 }  // namespace detail
 
 template <typename buffer_t>
diff --git a/include/ylt/coro_io/ibverbs/ib_socket.hpp b/include/ylt/coro_io/ibverbs/ib_socket.hpp
index ca4ef0cc2..e4f722ecc 100644
--- a/include/ylt/coro_io/ibverbs/ib_socket.hpp
+++ b/include/ylt/coro_io/ibverbs/ib_socket.hpp
@@ -91,7 +91,7 @@ struct ib_socket_shared_state_t
   std::queue<std::pair<std::error_code, std::size_t>>
       recv_result;  // TODO optimize with circle buffer
   callback_t recv_cb_;
-  callback_t send_cb_;
+  std::deque<callback_t> send_cb_;
   ib_buffer_t recv_buf_;
   std::shared_ptr<ib_buffer_pool_t> ib_buffer_pool_;
   std::unique_ptr<asio::posix::stream_descriptor> fd_;
@@ -182,7 +182,7 @@ struct ib_socket_shared_state_t
   struct resume_struct {
     std::error_code ec;
     std::size_t len;
-    callback_t* cb;
+    uint64_t wr_id;
   };
 
   void post_send_impl(std::span<ibv_sge> sge, callback_t&& handler) {
@@ -195,12 +195,11 @@ struct ib_socket_shared_state_t
          sge = std::move(sge_copy)]() mutable {
           ibv_send_wr sr{};
           ibv_send_wr* bad_wr = nullptr;
-          self->send_cb_ = std::move(handler);
           if (sge.size() && sge[0].lkey == 0) {
             sr.send_flags = IBV_SEND_INLINE;
           }
           sr.next = NULL;
-          sr.wr_id = (uintptr_t)&self->send_cb_;
+          sr.wr_id = 1;
           sr.sg_list = sge.data();
           sr.num_sge = sge.size();
           sr.opcode = IBV_WR_SEND;
@@ -211,13 +210,16 @@ struct ib_socket_shared_state_t
           }
           // post the receive request to the RQ
           else if (auto ec = ibv_post_send(self->qp_.get(), &sr, &bad_wr); ec) {
-            err = std::make_error_code(std::errc{std::abs(ec)});
+            err = std::make_error_code(std::errc{ec});
             ELOG_ERROR << "ibv post send failed: " << err.message();
           }
           if (err) {
             ib_socket_shared_state_t::resume(std::pair{err, std::size_t{0}},
                                              handler);
           }
+          else {
+            self->send_cb_.push_back(std::move(handler));
+          }
         },
         executor_->get_asio_executor())
         .start([](auto&& res) {
@@ -243,7 +245,7 @@ struct ib_socket_shared_state_t
     struct ibv_wc wc{};
     int ne = 0;
     std::vector<resume_struct> vec;
-    callback_t tmp_callback;
+    callback_t tmp_recv_callback;
     while ((ne = ibv_poll_cq(cq_.get(), 1, &wc)) != 0) {
       if (ne < 0) {
         ELOG_ERROR << "poll CQ failed:" << ne;
@@ -275,8 +277,8 @@ struct ib_socket_shared_state_t
                 close();
               }
             }
-            tmp_callback = std::move(recv_cb_);
-            vec.push_back({ec, wc.byte_len, &tmp_callback});
+            tmp_recv_callback = std::move(recv_cb_);
+            vec.push_back({ec, wc.byte_len, 0});
           }
           else {
             recv_result.push(std::pair{ec, (std::size_t)wc.byte_len});
@@ -289,7 +291,7 @@ struct ib_socket_shared_state_t
           }
         }
         else {
-          vec.push_back({ec, wc.byte_len, (callback_t*)wc.wr_id});
+          vec.push_back({ec, wc.byte_len, wc.wr_id});
         }
         if (cq_ == nullptr) {
           break;
@@ -297,7 +299,13 @@ struct ib_socket_shared_state_t
       }
     }
     for (auto& result : vec) {
-      resume(std::pair{result.ec, result.len}, *result.cb);
+      if (result.wr_id == 0) {
+        resume(std::pair{result.ec, result.len}, tmp_recv_callback);
+      }
+      else {
+        resume(std::pair{result.ec, result.len}, send_cb_.front());
+        send_cb_.pop_front();
+      }
     }
     return ec;
   }
@@ -333,7 +341,7 @@ struct ibverbs_config {
   uint32_t cq_size = 128;
   uint32_t recv_buffer_cnt = 4;
   ibv_qp_type qp_type = IBV_QPT_RC;
-  ibv_qp_cap cap = {.max_send_wr = 2,
+  ibv_qp_cap cap = {.max_send_wr = 32,
                     .max_recv_wr = 32,
                     .max_send_sge = 3,
                     .max_recv_sge = 1,
@@ -389,7 +397,8 @@ class ib_socket_t {
   ~ib_socket_t() { close(); }
 
   bool is_open() const noexcept {
-    return state_->fd_ != nullptr && state_->fd_->is_open();
+    return state_->fd_ != nullptr && state_->fd_->is_open() &&
+           !state_->has_close_;
   }
   std::shared_ptr<ib_buffer_pool_t> buffer_pool() const noexcept {
     return state_->ib_buffer_pool_;
@@ -799,7 +808,7 @@ class ib_socket_t {
   void init_fd() {
     int r = ibv_req_notify_cq(state_->cq_.get(), 0);
     if (r) {
-      auto err_code = std::make_error_code(std::errc{errno});
+      auto err_code = std::make_error_code(std::errc{r});
       ELOG_ERROR << "ibv_req_notify_cq failed: " << err_code.message();
       throw std::system_error(err_code);
     }
@@ -823,12 +832,15 @@ class ib_socket_t {
         }
 
         if (ec) {
-          auto send_cb = std::move(self->send_cb_);
           self->close();
           ib_socket_shared_state_t::resume(std::pair{ec, std::size_t{0}},
                                            self->recv_cb_);
-          ib_socket_shared_state_t::resume(std::pair{ec, std::size_t{0}},
-                                           send_cb);
+          while (!self->send_cb_.empty()) {
+            ib_socket_shared_state_t::resume(std::pair{ec, std::size_t{0}},
+                                             self->send_cb_.front());
+            self->send_cb_.pop_front();
+          }
+
           break;
         }
       }
diff --git a/src/coro_io/tests/ibverbs/CMakeLists.txt b/src/coro_io/tests/ibverbs/CMakeLists.txt
index 3186a1d0d..242e3b529 100644
--- a/src/coro_io/tests/ibverbs/CMakeLists.txt
+++ b/src/coro_io/tests/ibverbs/CMakeLists.txt
@@ -4,11 +4,16 @@ if(YLT_HAVE_IBVERBS)
 
   add_executable(ibverbs_test
     test_device.cpp
-    ib_socket_pressure_test.cpp
     test_ib_socket.cpp
     main.cpp
   )
+
+  add_executable(ibverbs_pressure_test
+    ib_socket_pressure_test.cpp     
+    main.cpp)
   
   target_link_libraries(ibverbs_test -libverbs)
+  target_link_libraries(ibverbs_pressure_test -libverbs)
   add_test(NAME ibverbs_test COMMAND ibverbs_test)
+  add_test(NAME ibverbs_pressure_test COMMAND ibverbs_pressure_test)
 endif()