Merge pull request #461 from mmichal10/evict-pinned

Evict pinned overflown ioclass

src/eviction/eviction.c

@@ -62,7 +62,7 @@ static inline uint32_t ocf_evict_part_do(ocf_cache_t cache,
 
 static inline uint32_t ocf_evict_partitions(ocf_cache_t cache,
 		ocf_queue_t io_queue, uint32_t evict_cline_no,
-		bool overflown_only, uint32_t max_priority)
+		bool overflown_only, int16_t max_priority)
 {
 	uint32_t to_evict = 0, evicted = 0;
 	struct ocf_user_part *part;
@@ -84,8 +84,9 @@ static inline uint32_t ocf_evict_partitions(ocf_cache_t cache,
 			 */
 			break;
 		}
-		if (!part->config->flags.eviction) {
+		if (!overflown_only && !part->config->flags.eviction) {
-			/* no more partitions available for viction
+			/* If partition is overflown it should be evcited
+			 * even if its pinned
 			 */
 			break;
 		}
@@ -132,8 +133,9 @@ static inline uint32_t ocf_evict_do(ocf_cache_t cache,
 	 * priority in this case, as overflown partitions should
 	 * free its cachelines regardless of destination partition
 	 * priority. */
+
 	evicted = ocf_evict_partitions(cache, io_queue, evict_cline_no,
-		true, OCF_IO_CLASS_PRIO_HIGHEST);
+		true, OCF_IO_CLASS_PRIO_PINNED);
 	if (evicted >= evict_cline_no)
 		return evicted;
 	/* Not enough cachelines in overflown partitions. Go through

tests/functional/tests/eviction/test_eviction.py

@@ -4,6 +4,7 @@
 #
 
 import logging
+from math import ceil, isclose
 from ctypes import c_int
 
 import pytest
@@ -12,7 +13,7 @@ from pyocf.types.cache import Cache, CacheMode
 from pyocf.types.core import Core
 from pyocf.types.data import Data
 from pyocf.types.io import IoDir
-from pyocf.types.shared import OcfCompletion, CacheLineSize, SeqCutOffPolicy
+from pyocf.types.shared import OcfCompletion, CacheLineSize, SeqCutOffPolicy, CacheLines
 from pyocf.types.volume import Volume
 from pyocf.utils import Size
 
@@ -74,10 +75,89 @@ def test_write_size_greater_than_cache(pyocf_ctx, mode: CacheMode, cls: CacheLin
         io_size_bigger_than_cache.blocks_4k
 
 
-def send_io(exported_obj: Core, data: Data, addr: int = 0):
+@pytest.mark.parametrize("cls", CacheLineSize)
+def test_evict_overflown_pinned(pyocf_ctx, cls: CacheLineSize):
+    """ Verify if overflown pinned ioclass is evicted """
+    cache_device = Volume(Size.from_MiB(35))
+    core_device = Volume(Size.from_MiB(100))
+    cache = Cache.start_on_device(
+        cache_device, cache_mode=CacheMode.WT, cache_line_size=cls
+    )
+    core = Core.using_device(core_device)
+    cache.add_core(core)
+
+    test_ioclass_id = 1
+    pinned_ioclass_id = 2
+    pinned_ioclass_max_occupancy = 10
+
+    cache.configure_partition(
+        part_id=test_ioclass_id,
+        name="default_ioclass",
+        min_size=0,
+        max_size=100,
+        priority=1,
+    )
+    cache.configure_partition(
+        part_id=pinned_ioclass_id,
+        name="pinned_ioclass",
+        min_size=0,
+        max_size=pinned_ioclass_max_occupancy,
+        priority=-1,
+    )
+
+    cache.set_seq_cut_off_policy(SeqCutOffPolicy.NEVER)
+
+    cache_size = cache.get_stats()["conf"]["size"]
+
+    data = Data(4096)
+
+    # Populate cache with data
+    for i in range(cache_size.blocks_4k):
+        send_io(core, data, i * 4096, test_ioclass_id)
+
+    part_current_size = CacheLines(
+        cache.get_partition_info(part_id=test_ioclass_id)["_curr_size"], cls
+    )
+    assert isclose(
+        part_current_size.blocks_4k, cache_size.blocks_4k, abs_tol=Size(cls).blocks_4k
+    ), "Failed to populate the default partition"
+
+    # Repart - force overflow of second partition occupancy limit
+    pinned_double_size = ceil(
+        (cache_size.blocks_4k * pinned_ioclass_max_occupancy * 2) / 100
+    )
+    for i in range(pinned_double_size):
+        send_io(core, data, i * 4096, pinned_ioclass_id)
+
+    part_current_size = CacheLines(
+        cache.get_partition_info(part_id=pinned_ioclass_id)["_curr_size"], cls
+    )
+    assert isclose(
+        part_current_size.blocks_4k, pinned_double_size, abs_tol=Size(cls).blocks_4k
+    ), "Occupancy of pinned ioclass doesn't match expected value"
+
+    # Trigger IO to the default ioclass - force eviction from overlown ioclass
+    for i in range(cache_size.blocks_4k):
+        send_io(core, data, (cache_size.blocks_4k + i) * 4096, test_ioclass_id)
+
+    part_current_size = CacheLines(
+        cache.get_partition_info(part_id=pinned_ioclass_id)["_curr_size"], cls
+    )
+    assert isclose(
+        part_current_size.blocks_4k,
+        ceil(cache_size.blocks_4k * 0.1),
+        abs_tol=Size(cls).blocks_4k,
+    ), "Overflown part has not been evicted"
+
+
+def send_io(exported_obj: Core, data: Data, addr: int = 0, target_ioclass: int = 0):
     io = exported_obj.new_io(
         exported_obj.cache.get_default_queue(),
-        addr, data.size, IoDir.WRITE, 0, 0
+        addr,
+        data.size,
+        IoDir.WRITE,
+        target_ioclass,
+        0,
     )
 
     io.set_data(data)