Migrate pipeline to 1ES (#4986)

nni/experiment/config/utils/internal.py

@@ -171,7 +171,8 @@ def load_training_service_config(config) -> TrainingServiceConfig:
         cls = _get_ts_config_class(config['platform'])
         if cls is not None:
             return cls(**config)
-    return config  # not valid json, don't touch
+    # not valid json, don't touch
+    return config  # type: ignore
 
 def _get_ts_config_class(platform: str) -> type[TrainingServiceConfig] | None:
     from ..training_service import TrainingServiceConfig  # avoid circular import

nni/retiarii/execution/base.py

@@ -10,6 +10,7 @@ import string
 from typing import Any, Dict, Iterable, List
 
 from nni.experiment import rest
+from nni.retiarii.integration import RetiariiAdvisor
 
 from .interface import AbstractExecutionEngine, AbstractGraphListener
 from .utils import get_mutation_summary
@@ -75,20 +76,21 @@ class BaseExecutionEngine(AbstractExecutionEngine):
         self.url_prefix = rest_url_prefix
 
         self._listeners: List[AbstractGraphListener] = []
-
-        # register advisor callbacks
-        advisor = get_advisor()
-        advisor.send_trial_callback = self._send_trial_callback
-        advisor.request_trial_jobs_callback = self._request_trial_jobs_callback
-        advisor.trial_end_callback = self._trial_end_callback
-        advisor.intermediate_metric_callback = self._intermediate_metric_callback
-        advisor.final_metric_callback = self._final_metric_callback
-
         self._running_models: Dict[int, Model] = dict()
         self._history: List[Model] = []
 
         self.resources = 0
 
+        # register advisor callbacks
+        advisor: RetiariiAdvisor = get_advisor()
+        advisor.register_callbacks({
+            'send_trial': self._send_trial_callback,
+            'request_trial_jobs': self._request_trial_jobs_callback,
+            'trial_end': self._trial_end_callback,
+            'intermediate_metric': self._intermediate_metric_callback,
+            'final_metric': self._final_metric_callback
+        })
+
     def submit_models(self, *models: Model) -> None:
         for model in models:
             data = self.pack_model_data(model)

nni/retiarii/execution/cgo_engine.py

@@ -14,6 +14,7 @@ from dataclasses import dataclass
 
 from nni.common.device import GPUDevice, Device
 from nni.experiment.config.training_services import RemoteConfig
+from nni.retiarii.integration import RetiariiAdvisor
 from .interface import AbstractExecutionEngine, AbstractGraphListener, WorkerInfo
 from .. import codegen, utils
 from ..graph import Model, ModelStatus, MetricData, Node
@@ -28,6 +29,10 @@ from .base import BaseGraphData
 _logger = logging.getLogger(__name__)
 
 
+def _noop(*args, **kwargs):
+    pass
+
+
 @dataclass
 class TrialSubmission:
     model: Model
@@ -90,12 +95,14 @@ class CGOExecutionEngine(AbstractExecutionEngine):
         self._queue_lock = threading.Lock()
 
         # register advisor callbacks
-        advisor = get_advisor()
-        # advisor.send_trial_callback = self._send_trial_callback
-        # advisor.request_trial_jobs_callback = self._request_trial_jobs_callback
-        advisor.trial_end_callback = self._trial_end_callback
-        advisor.intermediate_metric_callback = self._intermediate_metric_callback
-        advisor.final_metric_callback = self._final_metric_callback
+        advisor: RetiariiAdvisor = get_advisor()
+        advisor.register_callbacks({
+            'send_trial': _noop,
+            'request_trial_jobs': _noop,
+            'trial_end': self._trial_end_callback,
+            'intermediate_metric': self._intermediate_metric_callback,
+            'final_metric': self._final_metric_callback
+        })
 
         self._stopped = False
         self._consumer_thread = threading.Thread(target=self._consume_models)

nni/retiarii/integration.py

@@ -3,7 +3,7 @@
 
 import logging
 import os
-from typing import Any, Callable, Optional
+from typing import Any, Callable, Optional, Dict, List, Tuple
 
 import nni
 from nni.common.serializer import PayloadTooLarge
@@ -21,6 +21,7 @@ _logger = logging.getLogger(__name__)
 class RetiariiAdvisor(MsgDispatcherBase):
     """
     The class is to connect Retiarii components to NNI backend.
+    It can be considered as a Python wrapper of NNI manager.
 
     It will function as the main thread when running a Retiarii experiment through NNI.
     Strategy will be launched as its thread, who will call APIs in execution engine. Execution
@@ -32,9 +33,6 @@ class RetiariiAdvisor(MsgDispatcherBase):
     The conversion advisor provides are minimum. It is only a send/receive module, and execution engine
     needs to handle all the rest.
 
-    FIXME
-        How does advisor exit when strategy exists?
-
     Attributes
     ----------
     send_trial_callback
@@ -61,6 +59,63 @@ class RetiariiAdvisor(MsgDispatcherBase):
 
         self.parameters_count = 0
 
+        # Sometimes messages arrive first before the callbacks get registered.
+        # Or in case that we allow engine to be absent during the experiment.
+        # Here we need to store the messages and invoke them later.
+        self.call_queue: List[Tuple[str, list]] = []
+
+    def register_callbacks(self, callbacks: Dict[str, Callable[..., None]]):
+        """
+        Register callbacks for NNI backend.
+
+        Parameters
+        ----------
+        callbacks
+            A dictionary of callbacks.
+            The key is the name of the callback. The value is the callback function.
+        """
+        self.send_trial_callback = callbacks.get('send_trial')
+        self.request_trial_jobs_callback = callbacks.get('request_trial_jobs')
+        self.trial_end_callback = callbacks.get('trial_end')
+        self.intermediate_metric_callback = callbacks.get('intermediate_metric')
+        self.final_metric_callback = callbacks.get('final_metric')
+
+        self.process_queued_callbacks()
+
+    def process_queued_callbacks(self) -> None:
+        """
+        Process callbacks in queue.
+        Consume the messages that haven't been handled previously.
+        """
+        processed_idx = []
+        for queue_idx, (call_name, call_args) in enumerate(self.call_queue):
+            if call_name == 'send_trial' and self.send_trial_callback is not None:
+                self.send_trial_callback(*call_args)  # pylint: disable=not-callable
+                processed_idx.append(queue_idx)
+            if call_name == 'request_trial_jobs' and self.request_trial_jobs_callback is not None:
+                self.request_trial_jobs_callback(*call_args)  # pylint: disable=not-callable
+                processed_idx.append(queue_idx)
+            if call_name == 'trial_end' and self.trial_end_callback is not None:
+                self.trial_end_callback(*call_args)  # pylint: disable=not-callable
+                processed_idx.append(queue_idx)
+            if call_name == 'intermediate_metric' and self.intermediate_metric_callback is not None:
+                self.intermediate_metric_callback(*call_args)  # pylint: disable=not-callable
+                processed_idx.append(queue_idx)
+            if call_name == 'final_metric' and self.final_metric_callback is not None:
+                self.final_metric_callback(*call_args)  # pylint: disable=not-callable
+                processed_idx.append(queue_idx)
+
+        # Remove processed messages
+        for idx in reversed(processed_idx):
+            self.call_queue.pop(idx)
+
+    def invoke_callback(self, name: str, *args: Any) -> None:
+        """
+        Invoke callback.
+        """
+        self.call_queue.append((name, list(args)))
+        self.process_queued_callbacks()
+
     def handle_initialize(self, data):
         """callback for initializing the advisor
         Parameters
@@ -140,8 +195,7 @@ class RetiariiAdvisor(MsgDispatcherBase):
         # nevertheless, there could still be blocked by pipe / nni-manager
         self.send(CommandType.NewTrialJob, send_payload)
 
-        if self.send_trial_callback is not None:
-            self.send_trial_callback(parameters)  # pylint: disable=not-callable
+        self.invoke_callback('send_trial', parameters)
         return self.parameters_count
 
     def mark_experiment_as_ending(self):
@@ -149,8 +203,7 @@ class RetiariiAdvisor(MsgDispatcherBase):
 
     def handle_request_trial_jobs(self, num_trials):
         _logger.debug('Request trial jobs: %s', num_trials)
-        if self.request_trial_jobs_callback is not None:
-            self.request_trial_jobs_callback(num_trials)  # pylint: disable=not-callable
+        self.invoke_callback('request_trial_jobs', num_trials)
 
     def handle_update_search_space(self, data):
         _logger.debug('Received search space: %s', data)
@@ -158,22 +211,16 @@ class RetiariiAdvisor(MsgDispatcherBase):
 
     def handle_trial_end(self, data):
         _logger.debug('Trial end: %s', data)
-        if self.trial_end_callback is not None:
-            self.trial_end_callback(nni.load(data['hyper_params'])['parameter_id'],  # pylint: disable=not-callable
-                                    data['event'] == 'SUCCEEDED')
+        self.invoke_callback('trial_end', nni.load(data['hyper_params'])['parameter_id'], data['event'] == 'SUCCEEDED')
 
     def handle_report_metric_data(self, data):
         _logger.debug('Metric reported: %s', data)
         if data['type'] == MetricType.REQUEST_PARAMETER:
             raise ValueError('Request parameter not supported')
         elif data['type'] == MetricType.PERIODICAL:
-            if self.intermediate_metric_callback is not None:
-                self.intermediate_metric_callback(data['parameter_id'],  # pylint: disable=not-callable
-                                                  self._process_value(data['value']))
+            self.invoke_callback('intermediate_metric', data['parameter_id'], self._process_value(data['value']))
         elif data['type'] == MetricType.FINAL:
-            if self.final_metric_callback is not None:
-                self.final_metric_callback(data['parameter_id'],  # pylint: disable=not-callable
-                                           self._process_value(data['value']))
+            self.invoke_callback('final_metric', data['parameter_id'], self._process_value(data['value']))
 
     @staticmethod
     def _process_value(value) -> Any:  # hopefully a float

nni/retiarii/strategy/bruteforce.py

@@ -127,9 +127,11 @@ class Random(BaseStrategy):
                     if budget_exhausted():
                         return
                     time.sleep(self._polling_interval)
+                    _logger.debug('Still waiting for resource.')
                 try:
                     model = get_targeted_model(base_model, applied_mutators, sample)
                     if filter_model(self.filter, model):
+                        _logger.debug('Submitting model: %s', model)
                         submit_models(model)
                 except InvalidMutation as e:
                     _logger.warning(f'Invalid mutation: {e}. Skip.')

nni/tools/gpu_tool/gpu_metrics_collector.py

@@ -15,14 +15,19 @@ def main(argv):
     metrics_output_dir = os.environ['METRIC_OUTPUT_DIR']
 
     cmd = 'nvidia-smi -q -x'.split()
-    while(True):
-        try:
-            smi_output = subprocess.check_output(cmd)
-        except Exception:
-            traceback.print_exc()
+    retry = 0
+    while True:
+        smi = subprocess.run(cmd, timeout=20, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        if smi.returncode != 0:
+            retry += 1
+            print(f'gpu_metrics_collector error: nvidia-smi return code is {smi.returncode}', file=sys.stderr)
+            print('=' * 20 + f'\nCaptured stdout: {smi.stdout}', file=sys.stderr)
+            print('=' * 20 + f'\nCaptured stderr: {smi.stderr}', file=sys.stderr)
             gen_empty_gpu_metric(metrics_output_dir)
+            if retry >= 5:
                 break
-        parse_nvidia_smi_result(smi_output, metrics_output_dir)
+        else:
+            parse_nvidia_smi_result(smi.stdout, metrics_output_dir)
         # TODO: change to sleep time configurable via arguments
         time.sleep(5)
 

pipelines/build-vm-image-linux.yml

+# FIXME: This pipeline is broken due to resource group location limitation.
+
 trigger: none
 pr: none
 
@@ -11,6 +13,7 @@ variables:
 
 jobs:
 - job: linux
-  pool: nni-it
+  pool:
+    vmImage: ubuntu-latest
   steps:
   - template: templates/build-vm-image-template.yml

pipelines/build-vm-image-windows.yml

+# FIXME: This pipeline is broken due to resource group location limitation.
+
 trigger: none
 pr: none
 
@@ -11,7 +13,7 @@ variables:
 
 jobs:
 - job: windows
-  pool: nni-it
+  pool: nni-it-1es-11
   timeoutInMinutes: 90
   steps:
   - template: templates/build-vm-image-template.yml

pipelines/full-test-compression.yml

@@ -31,15 +31,18 @@ stages:
   condition: and(succeeded(), ne(dependencies.filter.outputs['check.execution.skipsubsequent'], 'true'))
   jobs:
   - job: linux
-    # move back after we complete the 1ES pool...
-    pool:
-      vmImage: ubuntu-latest
+    pool: nni-it-1es-11
     timeoutInMinutes: 60
 
     steps:
+    - template: templates/fix-apt-1es.yml
+      parameters:
+        check_gpu: true
+
     - template: templates/install-dependencies.yml
       parameters:
-        platform: ubuntu-latest
+        platform: ubuntu-latest-gpu
+        python_env: venv
 
     - template: templates/install-nni.yml
 
@@ -48,10 +51,9 @@ stages:
     - script: |
         cd test/algo
         python -m pytest compression
-      displayName: compression unit test
+      displayName: Compression unit test
 
-    # add back after we complete the 1ES pool...
-    # - script: |
-    #     cd test
-    #     source scripts/model_compression.sh
-    #   displayName: Model compression test
+    - script: |
+        cd test
+        source scripts/model_compression.sh
+      displayName: Model compression test

pipelines/full-test-hpo.yml

@@ -31,15 +31,18 @@ stages:
   condition: and(succeeded(), ne(dependencies.filter.outputs['check.execution.skipsubsequent'], 'true'))
   jobs:
   - job: linux
-    # move back after we complete the 1ES pool...
-    pool:
-      vmImage: ubuntu-latest
+    pool: nni-it-1es-11
     timeoutInMinutes: 60
 
     steps:
+    - template: templates/fix-apt-1es.yml
+      parameters:
+        check_gpu: true
+
     - template: templates/install-dependencies.yml
       parameters:
-        platform: ubuntu-latest
+        platform: ubuntu-latest-gpu
+        python_env: venv
 
     - template: templates/install-nni.yml
 
@@ -57,10 +60,7 @@ stages:
 
     - script: |
         cd test
-        python training_service/nnitest/run_tests.py \
-          --config training_service/config/integration_tests.yml \
-          --ts local \
-          --exclude mnist-pytorch-local-gpu
+        python training_service/nnitest/run_tests.py --config training_service/config/integration_tests.yml --ts local
       displayName: Integration test
 
   # TODO: should add a test on platforms other than linux

pipelines/full-test-nas.yml

@@ -31,15 +31,18 @@ stages:
   condition: and(succeeded(), ne(dependencies.filter.outputs['check.execution.skipsubsequent'], 'true'))
   jobs:
   - job: linux
-    # move back after we complete the 1ES pool...
-    pool:
-      vmImage: ubuntu-latest
+    pool: nni-it-1es-11
     timeoutInMinutes: 60
 
     steps:
+    - template: templates/fix-apt-1es.yml
+      parameters:
+        check_gpu: true
+
     - template: templates/install-dependencies.yml
       parameters:
-        platform: ubuntu-latest
+        platform: ubuntu-latest-gpu
+        python_env: venv
 
     - template: templates/install-nni.yml
 
@@ -51,15 +54,17 @@ stages:
       displayName: NAS test
 
   - job: windows
-    # move back after we complete the 1ES pool...
-    pool:
-      vmImage: windows-latest
+    pool: nni-it-1es-windows
     timeoutInMinutes: 60
 
     steps:
+    # FIXME: Windows should use GPU,
+    # but it's not used now since driver is not installed in the image.
+
     - template: templates/install-dependencies.yml
       parameters:
         platform: windows
+        python_env: noop
 
     - template: templates/install-nni.yml
       parameters:

pipelines/integration-test-hybrid.yml

@@ -7,11 +7,12 @@ schedules:
 
 jobs:
 - job: hybrid
-  pool: nni-it
+  pool: nni-it-1es-11
   timeoutInMinutes: 90
 
   steps:
   # FIXME: should use GPU here
+  - template: templates/fix-apt-1es.yml
 
   - template: templates/install-dependencies.yml
     parameters:

pipelines/integration-test-local-linux.yml

@@ -7,10 +7,14 @@ schedules:
 
 jobs:
 - job: linux
-  pool: nni-it
+  pool: nni-it-1es-11
   timeoutInMinutes: 60
 
   steps:
+  - template: templates/fix-apt-1es.yml
+    parameters:
+      check_gpu: true
+
   - template: templates/install-dependencies.yml
     parameters:
       platform: ubuntu-latest-gpu

pipelines/integration-test-local-windows.yml

@@ -7,7 +7,7 @@ schedules:
 
 jobs:
 - job: windows
-  pool: nni-it-windows
+  pool: nni-it-1es-windows
   timeoutInMinutes: 120
 
   steps:
@@ -43,3 +43,5 @@ jobs:
     displayName: Integration test
 
   - template: templates/save-crashed-info.yml
+    parameters:
+      training_service: local

pipelines/integration-test-remote-l2l.yml

@@ -12,10 +12,11 @@ schedules:
 
 jobs:
 - job: remote_linux2linux
-  pool: nni-it
+  pool: nni-it-1es-11
   timeoutInMinutes: 120
 
   steps:
+  - template: templates/fix-apt-1es.yml
   # FIXME: GPU is not supported yet.
   # Change to ubuntu-latest-gpu when it's done.
 
@@ -97,4 +98,4 @@ jobs:
 
   - template: templates/save-crashed-info.yml
     parameters:
-      remote: true
+      training_service: remote

pipelines/integration-test-remote-w2w.yml

@@ -11,7 +11,7 @@ variables:
 
 jobs:
 - job: remote_windows2windows
-  pool: nni-it-windows
+  pool: nni-it-1es-windows
   timeoutInMinutes: 120
 
   steps:
@@ -49,4 +49,4 @@ jobs:
 
   - template: templates/save-crashed-info.yml
     parameters:
-      remote: true
+      training_service: remote

pipelines/templates/build-vm-image-template.yml

@@ -8,8 +8,11 @@ steps:
 # 1. Assign the role following the instruction.
 # 2. Assign contributor role of the resource group to the identity.
 # 3. Add the identity to VMSS.
+#
+# Update 2022/7 (running on Microsoft-hosted agents).
+# Use a service principal. This service principal must be assigned contributor access to the resource group.
 - script: |
-    az login --identity --allow-no-subscriptions --username $(identity_id)
+    az login --service-principal -u $(client_id) -p $(client_secret) --tenant $(tenant_id)
   displayName: Login to Azure
 
 # Make sure all these are registered.
@@ -65,7 +68,8 @@ steps:
     export IP_ADDRESS=$(curl -s ifconfig.me)
     export VERSION=$(date "+%Y").$(date "+%m%d").$(date "+%H%M%S")
     export CONFIG_PATH=$(packer_config).json
-    sed -i -e "s/<client_id>/$(identity_id)/g" $CONFIG_PATH
+    sed -i -e "s/<client_id>/$(client_id)/g" $CONFIG_PATH
+    sed -i -e "s/<client_secret>/$(client_secret)/g" $CONFIG_PATH
     sed -i -e "s/<subscription_id>/$(subscription_id)/g" $CONFIG_PATH
     sed -i -e "s/<managed_image_name>/$(managed_image_name)/g" $CONFIG_PATH
     sed -i -e "s/<resource_group>/$(resource_group)/g" $CONFIG_PATH
@@ -113,3 +117,6 @@ steps:
 # az vmss update -n nni-it -g nni --set virtualMachineProfile.storageProfile.osDisk.diskSizeGb=50
 #
 # No need to update the image every time, because it's already set to latest.
+#
+# NOTE: After using 1ES pool, the pool image has to be updated manually to the latest version.
+# However, no successful build has been performed yet, because of resource shortage in Southeast Asia.

pipelines/templates/fix-apt-1es.yml

+# Fix apt-related issues on 1ES linux pipeline.
+
+# 1ES has an auto-upgraded with apt-get running in the background, periodically.
+# This leads to bad consequences:
+# 1) apt is locked when install is actually needed
+# 2) unattended upgrade could possibly break the GPU driver version, and crash nvidia-smi.
+#
+# The ultimate solution should be to upgrade the VM image correctly,
+# but it's currently infeasible because of a resource group limitation.
+# We introduce a workaround here by force disabling the auto-upgrade and,
+# fix the broken dependencies if upgrade has already been accidentally run.
+#
+# This file can be removed after image is updated to latest.
+
+parameters:
+- name: check_gpu
+  type: boolean
+  default: false
+
+steps:
+
+# Don't set -e
+# Always make sure the lock is released.
+- script: |
+    set -x
+    sudo bash test/vso_tools/build_vm/disable_apt_daily.sh
+    sudo apt-get -o DPkg::Lock::Timeout=120 --fix-broken -y install
+  displayName: (1ES) Disable apt upgrade
+
+# Make sure GPU isn't broken.
+# Sometimes we can't save the GPU because upgrade runs too early.
+# We have to rerun the pipeline if unlucky. But it doesn't matter if we don't intend to use GPU at all.
+- script: |
+    echo "There can be unlucky cases when we can't save the GPU. If nvidia-smi fails, try to rerun the failed jobs."
+    nvidia-smi
+  displayName: (1ES) Check GPU status
+  condition: and(succeeded(), ${{ parameters.check_gpu }})

pipelines/templates/save-crashed-info.yml

@@ -2,9 +2,9 @@
 # so that further offline investigations are possible.
 
 parameters:
-- name: remote
-  type: boolean
-  default: false
+- name: training_service
+  type: string
+  default: unknown
 
 steps:
 
@@ -16,11 +16,16 @@ steps:
   condition: and(failed(), not(contains(variables['Agent.OS'], 'Windows')))
   displayName: (failed) (POSIX) Latest experiment directory
 
+- script: |
+    cp -r /tmp/$USER/nni ${EXPERIMENT_DIR}/local && echo "Copy successful" || echo "Copy failed"
+  condition: and(variables['experiment_dir'], eq('${{ parameters.training_service }}', 'local'), not(contains(variables['Agent.OS'], 'Windows')))
+  displayName: (failed) (POSIX) Harvest GPU scheduler logs
+
 - script: |
     set -e
     export EXPERIMENT_ID=$(echo ${EXPERIMENT_DIR} | sed -e 's/\/.*\///g')
     sudo docker cp $(Build.BuildId):/tmp/nni-experiments/${EXPERIMENT_ID} ${EXPERIMENT_DIR}/remote && echo "Copy successful" || echo "Copy failed"
-  condition: and(variables['experiment_dir'], ${{ parameters.remote }}, not(contains(variables['Agent.OS'], 'Windows')))
+  condition: and(variables['experiment_dir'], eq('${{ parameters.training_service }}', 'remote'), not(contains(variables['Agent.OS'], 'Windows')))
   displayName: (failed) (POSIX) Harvest remote trial logs
 
 - powershell: |
@@ -30,6 +35,21 @@ steps:
   condition: and(failed(), contains(variables['Agent.OS'], 'Windows'))
   displayName: (failed) (Windows) Latest experiment directory
 
+- powershell: |
+    $latestDir = Get-Item $(experiment_dir)
+    $tmpPath = "${env:Temp}\${env:UserName}\nni"
+    $destPath = "${latestDir}\local"
+
+    if (Test-Path $tmpPath) {
+      Write-Host "Copying $tmpPath to $destPath"
+      Copy-Item $tmpPath -Destination $destPath -Recurse
+    }
+    else {
+      Write-host "$tmpPath doesn't exist"
+    }
+  condition: and(variables['experiment_dir'], eq('${{ parameters.training_service }}', 'local'), contains(variables['Agent.OS'], 'Windows'))
+  displayName: (failed) (Windows) Harvest GPU scheduler logs
+
 - powershell: |
     $latestDir = Get-Item $(experiment_dir)
     $experimentId = $latestDir.name
@@ -43,7 +63,7 @@ steps:
     else {
       Write-host "$remotePath doesn't exist"
     }
-  condition: and(variables['experiment_dir'], ${{ parameters.remote }}, contains(variables['Agent.OS'], 'Windows'))
+  condition: and(variables['experiment_dir'], eq('${{ parameters.training_service }}', 'remote'), contains(variables['Agent.OS'], 'Windows'))
   displayName: (failed) (Windows) Harvest remote trial logs
 
 - publish: $(experiment_dir)

test/ut/tools/nnictl/test_kill_command.py

@@ -53,8 +53,9 @@ def test_kill_process_slow_no_patience():
     start_time = time.time()
     kill_command(process.pid, timeout=1)  # didn't wait long enough
     end_time = time.time()
-    if sys.platform == 'linux':  # FIXME: on non-linux, seems that the time of termination can't be controlled
-        assert 0.5 < end_time - start_time < 2
+    if sys.platform == 'linux':
+        # There was assert 0.5 < end_time - start_time. It's not stable.
+        assert end_time - start_time < 2
         assert process.poll() is None
         assert _check_pid_running(process.pid)
     else:
@@ -73,8 +74,7 @@ def test_kill_process_slow_patiently():
     kill_command(process.pid, timeout=3)  # wait long enough
     end_time = time.time()
     assert end_time - start_time < 5
-    if sys.platform == 'linux':
-        assert end_time - start_time > 1  # I don't know why windows is super fast
+    # assert end_time - start_time > 1  # This check is disabled because it's not stable
 
 
 @pytest.mark.skipif(sys.platform != 'linux', reason='Signal issues on non-linux.')