From 9bdfa01f001dea9693b3eba93bd562185f4cf609 Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Wed, 8 Sep 2021 23:18:06 -0400
Subject: [PATCH 1/6] try windows with auto workers

---
 ci/azure/windows.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ci/azure/windows.yml b/ci/azure/windows.yml
index 05ba7c57ad6c4..e6fe76f224908 100644
--- a/ci/azure/windows.yml
+++ b/ci/azure/windows.yml
@@ -12,13 +12,13 @@ jobs:
         ENV_FILE: ci/deps/azure-windows-38.yaml
         CONDA_PY: "38"
         PATTERN: "not slow and not network"
-        PYTEST_WORKERS: 2  # GH-42236
+        PYTEST_WORKERS: "auto"
 
       py39:
         ENV_FILE: ci/deps/azure-windows-39.yaml
         CONDA_PY: "39"
         PATTERN: "not slow and not network and not high_memory"
-        PYTEST_WORKERS: 2  # GH-42236
+        PYTEST_WORKERS: "auto"
 
   steps:
     - powershell: |

From cf7550449c8c5623ebab14cb96ee7c2639bb1caf Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Thu, 9 Sep 2021 07:48:58 -0400
Subject: [PATCH 2/6] change pattern for skipping multiple tests

---
 ci/azure/windows.yml | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/ci/azure/windows.yml b/ci/azure/windows.yml
index e6fe76f224908..b186a0f82fa31 100644
--- a/ci/azure/windows.yml
+++ b/ci/azure/windows.yml
@@ -11,14 +11,12 @@ jobs:
       py38_np18:
         ENV_FILE: ci/deps/azure-windows-38.yaml
         CONDA_PY: "38"
-        PATTERN: "not slow and not network"
-        PYTEST_WORKERS: "auto"
+        PATTERN: "not (slow or network)"
 
       py39:
         ENV_FILE: ci/deps/azure-windows-39.yaml
         CONDA_PY: "39"
-        PATTERN: "not slow and not network and not high_memory"
-        PYTEST_WORKERS: "auto"
+        PATTERN: "not (slow or network or high_memory)"
 
   steps:
     - powershell: |

From a7d65b6020fee1acaa24d446d4abedcff1cff148 Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Thu, 9 Sep 2021 09:10:36 -0400
Subject: [PATCH 3/6] put back 2 workers

---
 ci/azure/windows.yml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ci/azure/windows.yml b/ci/azure/windows.yml
index b186a0f82fa31..8480607fa1878 100644
--- a/ci/azure/windows.yml
+++ b/ci/azure/windows.yml
@@ -12,11 +12,13 @@ jobs:
         ENV_FILE: ci/deps/azure-windows-38.yaml
         CONDA_PY: "38"
         PATTERN: "not (slow or network)"
+        PYTEST_WORKERS: 2  # GH-42236
 
       py39:
         ENV_FILE: ci/deps/azure-windows-39.yaml
         CONDA_PY: "39"
         PATTERN: "not (slow or network or high_memory)"
+        PYTEST_WORKERS: 2  # GH-42236
 
   steps:
     - powershell: |

From 70bdf08d97ad8e3139fee533b08cf1d1cf0b121f Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Thu, 9 Sep 2021 10:43:46 -0400
Subject: [PATCH 4/6] use one worker.  Use wmic to get CPU info

---
 ci/azure/windows.yml | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/ci/azure/windows.yml b/ci/azure/windows.yml
index 8480607fa1878..a53ef75f208a3 100644
--- a/ci/azure/windows.yml
+++ b/ci/azure/windows.yml
@@ -12,13 +12,13 @@ jobs:
         ENV_FILE: ci/deps/azure-windows-38.yaml
         CONDA_PY: "38"
         PATTERN: "not (slow or network)"
-        PYTEST_WORKERS: 2  # GH-42236
+        PYTEST_WORKERS: 1  # GH-43468
 
       py39:
         ENV_FILE: ci/deps/azure-windows-39.yaml
         CONDA_PY: "39"
         PATTERN: "not (slow or network or high_memory)"
-        PYTEST_WORKERS: 2  # GH-42236
+        PYTEST_WORKERS: 1  # GH-43468
 
   steps:
     - powershell: |
@@ -39,6 +39,7 @@ jobs:
       displayName: 'Build'
     - bash: |
         source activate pandas-dev
+        wmic.exe cpu get caption, deviceid, name, numberofcores, maxclockspeed
         ci/run_tests.sh
       displayName: 'Test'
     - task: PublishTestResults@2

From 6c3075ed2d230a6211a126d41468f5a6203147ca Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Thu, 9 Sep 2021 22:20:58 -0400
Subject: [PATCH 5/6] try splitting test targets via REs

---
 azure-pipelines.yml  |  1 +
 ci/azure/windows.yml | 28 ++++++++++++++++++++++------
 ci/run_tests.sh      |  2 +-
 3 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index e16fd36ac8f98..6c685d09ab55a 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -17,6 +17,7 @@ pr:
 
 variables:
   PYTEST_WORKERS: auto
+  PYTEST_TARGET:  pandas
 
 jobs:
 # Mac and Linux use the same template
diff --git a/ci/azure/windows.yml b/ci/azure/windows.yml
index a53ef75f208a3..f7a6a76dd0b6f 100644
--- a/ci/azure/windows.yml
+++ b/ci/azure/windows.yml
@@ -8,17 +8,33 @@ jobs:
     vmImage: ${{ parameters.vmImage }}
   strategy:
     matrix:
-      py38_np18:
+      py38_np18_1:
         ENV_FILE: ci/deps/azure-windows-38.yaml
         CONDA_PY: "38"
-        PATTERN: "not (slow or network)"
-        PYTEST_WORKERS: 1  # GH-43468
+        PATTERN: "not slow and not network"
+        PYTEST_WORKERS: 2  # GH-42236
+        PYTEST_TARGET: "pandas/tests/[a-i]*"
 
-      py39:
+      py38_np18_2:
+        ENV_FILE: ci/deps/azure-windows-38.yaml
+        CONDA_PY: "38"
+        PATTERN: "not slow and not network"
+        PYTEST_WORKERS: 2  # GH-42236
+        PYTEST_TARGET: "pandas/tests/[j-z]*"
+
+      py39_1:
+        ENV_FILE: ci/deps/azure-windows-39.yaml
+        CONDA_PY: "39"
+        PATTERN: "not slow and not network and not high_memory"
+        PYTEST_WORKERS: 2  # GH-42236
+        PYTEST_TARGET: "pandas/tests/[a-i]*"
+
+      py39_2:
         ENV_FILE: ci/deps/azure-windows-39.yaml
         CONDA_PY: "39"
-        PATTERN: "not (slow or network or high_memory)"
-        PYTEST_WORKERS: 1  # GH-43468
+        PATTERN: "not slow and not network and not high_memory"
+        PYTEST_WORKERS: 2  # GH-42236
+        PYTEST_TARGET: "pandas/tests/[j-z]*"
 
   steps:
     - powershell: |
diff --git a/ci/run_tests.sh b/ci/run_tests.sh
index 8304b89499465..53a2bf151d3bf 100755
--- a/ci/run_tests.sh
+++ b/ci/run_tests.sh
@@ -19,7 +19,7 @@ if [[ $(uname) == "Linux" && -z $DISPLAY ]]; then
     XVFB="xvfb-run "
 fi
 
-PYTEST_CMD="${XVFB}pytest -m \"$PATTERN\" -n $PYTEST_WORKERS --dist=loadfile $TEST_ARGS $COVERAGE pandas"
+PYTEST_CMD="${XVFB}pytest -m \"$PATTERN\" -n $PYTEST_WORKERS --dist=loadfile $TEST_ARGS $COVERAGE $PYTEST_TARGET"
 
 if [[ $(uname) != "Linux"  && $(uname) != "Darwin" ]]; then
     # GH#37455 windows py38 build appears to be running out of memory

From a5d56b91c349658fe648ae18f5c5eff27197291d Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Thu, 9 Sep 2021 23:09:41 -0400
Subject: [PATCH 6/6] add target for github workflows

---
 .github/workflows/ci.yml         | 1 +
 .github/workflows/posix.yml      | 1 +
 .github/workflows/python-dev.yml | 1 +
 3 files changed, 3 insertions(+)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e7a26a7905799..93c17997a95f7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -168,6 +168,7 @@ jobs:
         PANDAS_DATA_MANAGER: array
         PATTERN: ${{ matrix.pattern }}
         PYTEST_WORKERS: "auto"
+        PYTEST_TARGET: pandas
       run: |
         source activate pandas-dev
         ci/run_tests.sh
diff --git a/.github/workflows/posix.yml b/.github/workflows/posix.yml
index b707d583ab96a..f37f31686ef69 100644
--- a/.github/workflows/posix.yml
+++ b/.github/workflows/posix.yml
@@ -44,6 +44,7 @@ jobs:
       LC_ALL: ${{ matrix.settings[4] }}
       PANDAS_TESTING_MODE: ${{ matrix.settings[5] }}
       TEST_ARGS: ${{ matrix.settings[6] }}
+      PYTEST_TARGET:  pandas
     concurrency:
       group: ${{ github.ref }}-${{ matrix.settings[0] }}
       cancel-in-progress: ${{github.event_name == 'pull_request'}}
diff --git a/.github/workflows/python-dev.yml b/.github/workflows/python-dev.yml
index 7429155fe5023..596c3b6df9d49 100644
--- a/.github/workflows/python-dev.yml
+++ b/.github/workflows/python-dev.yml
@@ -17,6 +17,7 @@ env:
   PANDAS_CI: 1
   PATTERN: "not slow and not network and not clipboard"
   COVERAGE: true
+  PYTEST_TARGET:  pandas
 
 jobs:
   build: