diff --git a/.github/workflows/static.yml b/.github/workflows/static.yml
index 60a2eecc..ead721a7 100644
--- a/.github/workflows/static.yml
+++ b/.github/workflows/static.yml
@@ -8,11 +8,9 @@ on:
   pull_request:
 
 env:
+  DEEPLINK_PATH: /mnt/cache/share/deeplinkci/github/${{ github.repository }}
   ENV_SOURCE: /mnt/cache/share/platform/env/dipu_latest
   PROXY_SOURCE: /mnt/cache/share/platform/env/proxy
-  WORKSPACE: /mnt/cache/share/deeplinkci/github/${{ github.repository }}/${{ github.run_number }}
-  CODE_SOURCE: source
-  CLANGD_TIDY_SOURCE: clangd-tidy
   CLANGD_EXEC: /mnt/cache/share/platform/dep/clang-17/bin/clangd
 
 concurrency:
@@ -20,21 +18,37 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  checkout-code:
-    name: checkout code
+  static-checks-on-sco:
+    name: static checks on sco
     runs-on: tps-sco-ci
     steps:
-      - name: prepare workspace
+      - name: setting up environment
         run: |
           set -euxo pipefail
-          mkdir -p ${WORKSPACE} && cd ${WORKSPACE} && pwd
+          set_env() {
+            expr="$1=\"$2\""
+            echo "$expr" >> "${GITHUB_ENV}"
+            eval $expr
+          }
+          set_env WORKSPACE "${DEEPLINK_PATH}/${{ github.run_number }}"
+          set_env CODE_SOURCE "${WORKSPACE}/source"
+          set_env CLANGD_TIDY_SOURCE "${WORKSPACE}/clangd-tidy"
+          set_env CLANGD_TIDY_LOG "${WORKSPACE}/clang-tidy.log"
+      - name: clean obsolete workspaces & prepare workspace
+        run: |
+          set -euxo pipefail
+          echo ${CODE_SOURCE}
+          false
+          ls -la ${DEEPLINK_PATH}
+          rm -rf ${WORKSPACE}
+          find ${DEEPLINK_PATH} -maxdepth 1 -mmin +480 -type d -exec bash -c 'echo clean "$0" && rm -rf "$0"' {} \;
+          mkdir -p ${WORKSPACE}
       - name: checkout code
         run: |
           set -euo pipefail
           source ${PROXY_SOURCE}
           set -x
-          cd ${WORKSPACE} && pwd
-          [[ ! -d ${CODE_SOURCE} ]] || rm -rf ${CODE_SOURCE}
+          rm -rf ${CODE_SOURCE}
           if [ -n "${{ github.event.pull_request.head.repo.full_name }}" ] && [[ ! "${{ github.event.pull_request.head.repo.full_name }}" == "${{ github.repository }}" ]]; then
             git clone ${{ github.event.pull_request.head.repo.clone_url }} ${CODE_SOURCE}
             cd ${CODE_SOURCE} && git checkout ${{ github.event.pull_request.head.sha }}
@@ -54,19 +68,17 @@ jobs:
           set -euo pipefail
           source ${PROXY_SOURCE}
           set -x
-          cd ${WORKSPACE}/${CODE_SOURCE} && pwd
           git -c advice.detachedHead=false clone --depth 1 -b v0.1.3 https://github.com/lljbash/clangd-tidy.git ${CLANGD_TIDY_SOURCE}
-
-  build-and-tidy:
-    name: build and tidy
-    runs-on: tps-sco-ci
-    needs: [checkout-code]
-    steps:
       - name: build
         run: |
           set -euxo pipefail
-          srun --job-name=${GITHUB_JOB} bash -c "source ${ENV_SOURCE} && cd ${WORKSPACE}/${CODE_SOURCE} && pwd && pip install -e . -v -t install"
+          srun --job-name=${GITHUB_JOB} bash -c "source ${ENV_SOURCE} && cd ${CODE_SOURCE} && pwd && pip install -e . -v -t install"
       - name: clang-tidy
         run: |
           set -euxo pipefail
-          srun --job-name=${GITHUB_JOB} bash -c "source ${ENV_SOURCE} && cd ${WORKSPACE}/${CODE_SOURCE} && pwd && git ls-files csrc | xargs ${CLANGD_TIDY_SOURCE}/clangd-tidy --clangd-executable=${CLANGD_EXEC} --github --git-root=${WORKSPACE}/${CODE_SOURCE} -j4 -o clang-tidy.log" || (cat ${WORKSPACE}/${CODE_SOURCE}/clang-tidy.log && false)
+          srun --job-name=${GITHUB_JOB} bash -c "source ${ENV_SOURCE} && cd ${CODE_SOURCE} && pwd && git ls-files csrc | xargs ${CLANGD_TIDY_SOURCE}/clangd-tidy --clangd-executable=${CLANGD_EXEC} --github --git-root=${CODE_SOURCE} -j4 -o ${CLANGD_TIDY_LOG} || (cat ${CLANGD_TIDY_LOG} && false)
+      - name: cleanup
+        if: always()
+        run: |
+          set -euxo pipefail
+          rm -rf ${CODE_SOURCE}/build/.cache