Add tests for promotion policy

Signed-off-by: Katarzyna Treder <[email protected]>

test/functional/tests/cache_ops/test_promotion.py

@@ -0,0 +1,237 @@
+#
+# Copyright(c) 2024 Huawei Technologies
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import math
+import random
+import pytest
+
+from api.cas import casadm
+from api.cas.cache_config import SeqCutOffPolicy, CleaningPolicy, PromotionPolicy, \
+    PromotionParametersNhit, CacheMode
+from core.test_run import TestRun
+from storage_devices.disk import DiskTypeSet, DiskType, DiskTypeLowerThan
+from test_tools.dd import Dd
+from test_utils.os_utils import Udev
+from test_utils.size import Size, Unit
+
+
+@pytest.mark.require_disk("cache", DiskTypeSet([DiskType.optane, DiskType.nand]))
+@pytest.mark.require_disk("core", DiskTypeLowerThan("cache"))
+def test_promotion_policy_nhit_threshold():
+    """
+    title: Functional test for promotion policy nhit - threshold
+    description: |
+        Test checking if data is cached only after number of hits to given cache line
+        accordingly to specified promotion nhit threshold.
+    pass_criteria:
+      - Promotion policy and hit parameters are set properly
+      - Data is cached only after number of hits to given cache line specified by threshold param
+      - Data is written in pass-through before number of hits to given cache line specified by
+        threshold param
+      - After meeting specified number of hits to given cache line, writes to other cache lines
+        are handled in pass-through
+    """
+    random_thresholds = random.sample(range(2, 1000), 10)
+    additional_writes_count = 10
+
+    with TestRun.step("Prepare cache and core devices"):
+        cache_device = TestRun.disks["cache"]
+        core_device = TestRun.disks["core"]
+
+        cache_device.create_partitions([Size(value=5, unit=Unit.GibiByte)])
+        core_device.create_partitions([Size(value=10, unit=Unit.GibiByte)])
+
+        cache_part = cache_device.partitions[0]
+        core_parts = core_device.partitions[0]
+
+    with TestRun.step("Disable udev"):
+        Udev.disable()
+
+    with TestRun.step("Start cache and add core"):
+        cache = casadm.start_cache(cache_part, cache_mode=CacheMode.WB)
+        core = cache.add_core(core_parts)
+
+    with TestRun.step("Disable sequential cut-off and cleaning"):
+        cache.set_seq_cutoff_policy(SeqCutOffPolicy.never)
+        cache.set_cleaning_policy(CleaningPolicy.nop)
+        cache.reset_counters()
+
+    with TestRun.step("Check if statistics of writes to cache and writes to core are zeros"):
+        check_statistics(
+            cache,
+            expected_writes_to_cache=Size.zero(),
+            expected_writes_to_core=Size.zero()
+        )
+
+    with TestRun.step("Set nhit promotion policy"):
+        cache.set_promotion_policy(PromotionPolicy.nhit)
+
+    for iteration, threshold in enumerate(
+            TestRun.iteration(
+                random_thresholds,
+                "Set and validate nhit promotion policy threshold"
+            )
+    ):
+        with TestRun.step(f"Set threshold to {threshold} and trigger to 0%"):
+            cache.set_params_nhit(
+                PromotionParametersNhit(
+                    threshold=threshold,
+                    trigger=0
+                )
+            )
+
+        with TestRun.step("Reset cache counters."):
+            cache.reset_counters()
+
+        with TestRun.step(
+                "Run dd and check if number of writes to cache and writes to core increase "
+                "accordingly to nhit parameters"
+        ):
+            # dd_seek is counted as below to use different part of the cache in each iteration
+            dd_seek = int(
+                cache.size.get_value(Unit.Blocks4096) // len(random_thresholds) * iteration
+            )
+
+            for count in range(1, threshold + additional_writes_count):
+                run_dd(path=core.path, count=1, seek=dd_seek)
+                if count < threshold:
+                    expected_writes_to_cache = Size.zero()
+                    expected_writes_to_core = Size(count, Unit.Blocks4096)
+                else:
+                    expected_writes_to_cache = Size(count - threshold + 1, Unit.Blocks4096)
+                    expected_writes_to_core = Size(threshold - 1, Unit.Blocks4096)
+                check_statistics(cache, expected_writes_to_cache, expected_writes_to_core)
+
+        with TestRun.step("Write to other cache line and check if it was handled in pass-through"):
+            run_dd(path=core.path, count=1, seek=int(dd_seek + Unit.Blocks4096.value))
+            expected_writes_to_core = expected_writes_to_core + Size(1, Unit.Blocks4096)
+            check_statistics(cache, expected_writes_to_cache, expected_writes_to_core)
+
+
+@pytest.mark.require_disk("cache", DiskTypeSet([DiskType.optane, DiskType.nand]))
+@pytest.mark.require_disk("core", DiskTypeLowerThan("cache"))
+def test_promotion_policy_nhit_trigger():
+    """
+    title: Functional test for promotion policy nhit - trigger
+    description: |
+        Test checking if data is cached accordingly to nhit threshold parameter only after reaching
+        cache occupancy specified by nhit trigger value
+    pass_criteria:
+      - Promotion policy and hit parameters are set properly
+      - Data is cached only accordingly to nhit threshold parameter only after reaching
+        cache occupancy specified by nhit trigger value
+      - Data is written in pass-through before reaching cache occupancy specified by
+        nhit trigger value
+    """
+    random_triggers = random.sample(range(0, 100), 10)
+    threshold = 2
+
+    with TestRun.step("Prepare cache and core devices"):
+        cache_device = TestRun.disks["cache"]
+        core_device = TestRun.disks["core"]
+
+        cache_device.create_partitions([Size(value=50, unit=Unit.MebiByte)])
+        core_device.create_partitions([Size(value=100, unit=Unit.MebiByte)])
+
+        cache_part = cache_device.partitions[0]
+        core_parts = core_device.partitions[0]
+
+    with TestRun.step("Disable udev"):
+        Udev.disable()
+
+    for trigger in TestRun.iteration(
+                random_triggers,
+                "Validate nhit promotion policy trigger"
+    ):
+        with TestRun.step("Start cache and add core"):
+            cache = casadm.start_cache(cache_part, cache_mode=CacheMode.WB, force=True)
+            core = cache.add_core(core_parts)
+
+        with TestRun.step("Disable sequential cut-off and cleaning"):
+            cache.set_seq_cutoff_policy(SeqCutOffPolicy.never)
+            cache.set_cleaning_policy(CleaningPolicy.nop)
+            cache.reset_counters()
+
+        with TestRun.step("Check if statistics of writes to cache and writes to core are zeros"):
+            check_statistics(
+                cache,
+                expected_writes_to_cache=Size.zero(),
+                expected_writes_to_core=Size.zero()
+            )
+
+        with TestRun.step("Set nhit promotion policy"):
+            cache.set_promotion_policy(PromotionPolicy.nhit)
+
+        with TestRun.step(f"Set threshold to {threshold} and trigger to {trigger}%"):
+            cache.set_params_nhit(
+                PromotionParametersNhit(
+                    threshold=threshold,
+                    trigger=trigger
+                )
+            )
+
+        with TestRun.step(f"Run dd to fill {trigger}% of cache size with data"):
+            blocks_count = math.ceil(cache.size.get_value(Unit.Blocks4096) * trigger / 100)
+            run_dd(path=core.path, count=blocks_count, seek=0)
+
+        with TestRun.step("Check if all written data was cached"):
+            check_statistics(
+                cache,
+                expected_writes_to_cache=Size(blocks_count, Unit.Blocks4096),
+                expected_writes_to_core=Size.zero()
+            )
+
+        with TestRun.step("Write to free cached volume sectors"):
+            free_seek = (blocks_count + 1)
+            pt_blocks_count = int(cache.size.get_value(Unit.Blocks4096) - blocks_count)
+            run_dd(path=core.path, count=pt_blocks_count, seek=free_seek)
+
+        with TestRun.step("Check if recently written data was written in pass-through"):
+            check_statistics(
+                cache,
+                expected_writes_to_cache=Size(blocks_count, Unit.Blocks4096),
+                expected_writes_to_core=Size(pt_blocks_count, Unit.Blocks4096)
+            )
+
+        with TestRun.step("Write to recently written sectors one more time"):
+            run_dd(path=core.path, count=pt_blocks_count, seek=free_seek)
+
+        with TestRun.step("Check if recently written data was cached"):
+            check_statistics(
+                cache,
+                expected_writes_to_cache=Size(blocks_count + pt_blocks_count, Unit.Blocks4096),
+                expected_writes_to_core=Size(pt_blocks_count, Unit.Blocks4096)
+            )
+
+        with TestRun.step("Stop cache"):
+            cache.stop(no_data_flush=True)
+
+
+def run_dd(path, count, seek=None):
+    dd = Dd().input("/dev/random") \
+        .output(path) \
+        .oflag("direct") \
+        .block_size(Size(1, Unit.Blocks4096)) \
+        .count(count)
+    if seek:
+        dd.seek(seek)
+    dd.run()
+
+
+def check_statistics(cache, expected_writes_to_cache, expected_writes_to_core):
+    cache_stats = cache.get_statistics()
+    writes_to_cache = cache_stats.block_stats.cache.writes
+    writes_to_core = cache_stats.block_stats.core.writes
+
+    if writes_to_cache != expected_writes_to_cache:
+        TestRun.LOGGER.error(
+            f"Number of writes to cache should be "
+            f"{expected_writes_to_cache.get_value(Unit.Blocks4096)} "
+            f"but it is {writes_to_cache.get_value(Unit.Blocks4096)}")
+    if writes_to_core != expected_writes_to_core:
+        TestRun.LOGGER.error(
+            f"Number of writes to core should be: "
+            f"{expected_writes_to_core.get_value(Unit.Blocks4096)} "
+            f"but it is {writes_to_core.get_value(Unit.Blocks4096)}")