[ovs-dev] [PATCH 2/8] dpif-netdev: refactor emc and smc into dfc header
Harry van Haaren
harry.van.haaren at intel.com
Tue Oct 6 14:54:31 UTC 2020
This commit moves the EMC and SMC implementations and data-
structures out of the very large dpif-netdev.c file, and into
its own header file. No functional changes are made here, only
movement of code between files.
Signed-off-by: Harry van Haaren <harry.van.haaren at intel.com>
---
lib/automake.mk | 1 +
lib/dpif-netdev-private-dfc.h | 204 ++++++++++++++++++++++++++++++++++
lib/dpif-netdev.c | 169 +---------------------------
3 files changed, 206 insertions(+), 168 deletions(-)
create mode 100644 lib/dpif-netdev-private-dfc.h
diff --git a/lib/automake.mk b/lib/automake.mk
index 380a67228..9b0cdeb54 100644
--- a/lib/automake.mk
+++ b/lib/automake.mk
@@ -111,6 +111,7 @@ lib_libopenvswitch_la_SOURCES = \
lib/dpif-netdev-lookup-generic.c \
lib/dpif-netdev.c \
lib/dpif-netdev.h \
+ lib/dpif-netdev-private-dfc.h \
lib/dpif-netdev-private.h \
lib/dpif-netdev-perf.c \
lib/dpif-netdev-perf.h \
diff --git a/lib/dpif-netdev-private-dfc.h b/lib/dpif-netdev-private-dfc.h
new file mode 100644
index 000000000..f3c1aa338
--- /dev/null
+++ b/lib/dpif-netdev-private-dfc.h
@@ -0,0 +1,204 @@
+/*
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2015 Nicira, Inc.
+ * Copyright (c) 2019, 2020 Intel Corperation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef DPIF_NETDEV_PRIVATE_DFC_H
+#define DPIF_NETDEV_PRIVATE_DFC_H 1
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "dpif.h"
+#include "cmap.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* EMC cache and SMC cache compose the datapath flow cache (DFC)
+ *
+ * Exact match cache for frequently used flows
+ *
+ * The cache uses a 32-bit hash of the packet (which can be the RSS hash) to
+ * search its entries for a miniflow that matches exactly the miniflow of the
+ * packet. It stores the 'dpcls_rule' (rule) that matches the miniflow.
+ *
+ * A cache entry holds a reference to its 'dp_netdev_flow'.
+ *
+ * A miniflow with a given hash can be in one of EM_FLOW_HASH_SEGS different
+ * entries. The 32-bit hash is split into EM_FLOW_HASH_SEGS values (each of
+ * them is EM_FLOW_HASH_SHIFT bits wide and the remainder is thrown away). Each
+ * value is the index of a cache entry where the miniflow could be.
+ *
+ *
+ * Signature match cache (SMC)
+ *
+ * This cache stores a 16-bit signature for each flow without storing keys, and
+ * stores the corresponding 16-bit flow_table index to the 'dp_netdev_flow'.
+ * Each flow thus occupies 32bit which is much more memory efficient than EMC.
+ * SMC uses a set-associative design that each bucket contains
+ * SMC_ENTRY_PER_BUCKET number of entries.
+ * Since 16-bit flow_table index is used, if there are more than 2^16
+ * dp_netdev_flow, SMC will miss them that cannot be indexed by a 16-bit value.
+ *
+ *
+ * Thread-safety
+ * =============
+ *
+ * Each pmd_thread has its own private exact match cache.
+ * If dp_netdev_input is not called from a pmd thread, a mutex is used.
+ */
+
+#define EM_FLOW_HASH_SHIFT 13
+#define EM_FLOW_HASH_ENTRIES (1u << EM_FLOW_HASH_SHIFT)
+#define EM_FLOW_HASH_MASK (EM_FLOW_HASH_ENTRIES - 1)
+#define EM_FLOW_HASH_SEGS 2
+
+/* SMC uses a set-associative design. A bucket contains a set of entries that
+ * a flow item can occupy. For now, it uses one hash function rather than two
+ * as for the EMC design. */
+#define SMC_ENTRY_PER_BUCKET 4
+#define SMC_ENTRIES (1u << 20)
+#define SMC_BUCKET_CNT (SMC_ENTRIES / SMC_ENTRY_PER_BUCKET)
+#define SMC_MASK (SMC_BUCKET_CNT - 1)
+
+/* Default EMC insert probability is 1 / DEFAULT_EM_FLOW_INSERT_INV_PROB */
+#define DEFAULT_EM_FLOW_INSERT_INV_PROB 100
+#define DEFAULT_EM_FLOW_INSERT_MIN (UINT32_MAX / \
+ DEFAULT_EM_FLOW_INSERT_INV_PROB)
+
+struct emc_entry {
+ struct dp_netdev_flow *flow;
+ struct netdev_flow_key key; /* key.hash used for emc hash value. */
+};
+
+struct emc_cache {
+ struct emc_entry entries[EM_FLOW_HASH_ENTRIES];
+ int sweep_idx; /* For emc_cache_slow_sweep(). */
+};
+
+struct smc_bucket {
+ uint16_t sig[SMC_ENTRY_PER_BUCKET];
+ uint16_t flow_idx[SMC_ENTRY_PER_BUCKET];
+};
+
+/* Signature match cache, differentiate from EMC cache */
+struct smc_cache {
+ struct smc_bucket buckets[SMC_BUCKET_CNT];
+};
+
+struct dfc_cache {
+ struct emc_cache emc_cache;
+ struct smc_cache smc_cache;
+};
+
+/* Iterate in the exact match cache through every entry that might contain a
+ * miniflow with hash 'HASH'. */
+#define EMC_FOR_EACH_POS_WITH_HASH(EMC, CURRENT_ENTRY, HASH) \
+ for (uint32_t i__ = 0, srch_hash__ = (HASH); \
+ (CURRENT_ENTRY) = &(EMC)->entries[srch_hash__ & EM_FLOW_HASH_MASK], \
+ i__ < EM_FLOW_HASH_SEGS; \
+ i__++, srch_hash__ >>= EM_FLOW_HASH_SHIFT)
+
+/* These cannot be moved to .h yet as they dereference dp_netdev_flow */
+static inline bool emc_entry_alive(struct emc_entry *ce);
+static void emc_clear_entry(struct emc_entry *ce);
+
+static void
+smc_clear_entry(struct smc_bucket *b, int idx)
+{
+ b->flow_idx[idx] = UINT16_MAX;
+}
+
+static void
+emc_cache_init(struct emc_cache *flow_cache)
+{
+ int i;
+
+ flow_cache->sweep_idx = 0;
+ for (i = 0; i < ARRAY_SIZE(flow_cache->entries); i++) {
+ flow_cache->entries[i].flow = NULL;
+ flow_cache->entries[i].key.hash = 0;
+ flow_cache->entries[i].key.len = sizeof(struct miniflow);
+ flowmap_init(&flow_cache->entries[i].key.mf.map);
+ }
+}
+
+static void
+smc_cache_init(struct smc_cache *smc_cache)
+{
+ int i, j;
+ for (i = 0; i < SMC_BUCKET_CNT; i++) {
+ for (j = 0; j < SMC_ENTRY_PER_BUCKET; j++) {
+ smc_cache->buckets[i].flow_idx[j] = UINT16_MAX;
+ }
+ }
+}
+
+static void
+dfc_cache_init(struct dfc_cache *flow_cache)
+{
+ emc_cache_init(&flow_cache->emc_cache);
+ smc_cache_init(&flow_cache->smc_cache);
+}
+
+static void
+emc_cache_uninit(struct emc_cache *flow_cache)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(flow_cache->entries); i++) {
+ emc_clear_entry(&flow_cache->entries[i]);
+ }
+}
+
+static void
+smc_cache_uninit(struct smc_cache *smc)
+{
+ int i, j;
+
+ for (i = 0; i < SMC_BUCKET_CNT; i++) {
+ for (j = 0; j < SMC_ENTRY_PER_BUCKET; j++) {
+ smc_clear_entry(&(smc->buckets[i]), j);
+ }
+ }
+}
+
+static void
+dfc_cache_uninit(struct dfc_cache *flow_cache)
+{
+ smc_cache_uninit(&flow_cache->smc_cache);
+ emc_cache_uninit(&flow_cache->emc_cache);
+}
+
+/* Check and clear dead flow references slowly (one entry at each
+ * invocation). */
+static void
+emc_cache_slow_sweep(struct emc_cache *flow_cache)
+{
+ struct emc_entry *entry = &flow_cache->entries[flow_cache->sweep_idx];
+
+ if (!emc_entry_alive(entry)) {
+ emc_clear_entry(entry);
+ }
+ flow_cache->sweep_idx = (flow_cache->sweep_idx + 1) & EM_FLOW_HASH_MASK;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* dpif-netdev-private-dfc.h */
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index dbbacfa36..c86a98870 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -44,6 +44,7 @@
#include "dpif.h"
#include "dpif-netdev-lookup.h"
#include "dpif-netdev-perf.h"
+#include "dpif-netdev-private-dfc.h"
#include "dpif-provider.h"
#include "dummy.h"
#include "fat-rwlock.h"
@@ -142,90 +143,6 @@ static struct odp_support dp_netdev_support = {
.ct_orig_tuple6 = true,
};
-/* EMC cache and SMC cache compose the datapath flow cache (DFC)
- *
- * Exact match cache for frequently used flows
- *
- * The cache uses a 32-bit hash of the packet (which can be the RSS hash) to
- * search its entries for a miniflow that matches exactly the miniflow of the
- * packet. It stores the 'dpcls_rule' (rule) that matches the miniflow.
- *
- * A cache entry holds a reference to its 'dp_netdev_flow'.
- *
- * A miniflow with a given hash can be in one of EM_FLOW_HASH_SEGS different
- * entries. The 32-bit hash is split into EM_FLOW_HASH_SEGS values (each of
- * them is EM_FLOW_HASH_SHIFT bits wide and the remainder is thrown away). Each
- * value is the index of a cache entry where the miniflow could be.
- *
- *
- * Signature match cache (SMC)
- *
- * This cache stores a 16-bit signature for each flow without storing keys, and
- * stores the corresponding 16-bit flow_table index to the 'dp_netdev_flow'.
- * Each flow thus occupies 32bit which is much more memory efficient than EMC.
- * SMC uses a set-associative design that each bucket contains
- * SMC_ENTRY_PER_BUCKET number of entries.
- * Since 16-bit flow_table index is used, if there are more than 2^16
- * dp_netdev_flow, SMC will miss them that cannot be indexed by a 16-bit value.
- *
- *
- * Thread-safety
- * =============
- *
- * Each pmd_thread has its own private exact match cache.
- * If dp_netdev_input is not called from a pmd thread, a mutex is used.
- */
-
-#define EM_FLOW_HASH_SHIFT 13
-#define EM_FLOW_HASH_ENTRIES (1u << EM_FLOW_HASH_SHIFT)
-#define EM_FLOW_HASH_MASK (EM_FLOW_HASH_ENTRIES - 1)
-#define EM_FLOW_HASH_SEGS 2
-
-/* SMC uses a set-associative design. A bucket contains a set of entries that
- * a flow item can occupy. For now, it uses one hash function rather than two
- * as for the EMC design. */
-#define SMC_ENTRY_PER_BUCKET 4
-#define SMC_ENTRIES (1u << 20)
-#define SMC_BUCKET_CNT (SMC_ENTRIES / SMC_ENTRY_PER_BUCKET)
-#define SMC_MASK (SMC_BUCKET_CNT - 1)
-
-/* Default EMC insert probability is 1 / DEFAULT_EM_FLOW_INSERT_INV_PROB */
-#define DEFAULT_EM_FLOW_INSERT_INV_PROB 100
-#define DEFAULT_EM_FLOW_INSERT_MIN (UINT32_MAX / \
- DEFAULT_EM_FLOW_INSERT_INV_PROB)
-
-struct emc_entry {
- struct dp_netdev_flow *flow;
- struct netdev_flow_key key; /* key.hash used for emc hash value. */
-};
-
-struct emc_cache {
- struct emc_entry entries[EM_FLOW_HASH_ENTRIES];
- int sweep_idx; /* For emc_cache_slow_sweep(). */
-};
-
-struct smc_bucket {
- uint16_t sig[SMC_ENTRY_PER_BUCKET];
- uint16_t flow_idx[SMC_ENTRY_PER_BUCKET];
-};
-
-/* Signature match cache, differentiate from EMC cache */
-struct smc_cache {
- struct smc_bucket buckets[SMC_BUCKET_CNT];
-};
-
-struct dfc_cache {
- struct emc_cache emc_cache;
- struct smc_cache smc_cache;
-};
-
-/* Iterate in the exact match cache through every entry that might contain a
- * miniflow with hash 'HASH'. */
-#define EMC_FOR_EACH_POS_WITH_HASH(EMC, CURRENT_ENTRY, HASH) \
- for (uint32_t i__ = 0, srch_hash__ = (HASH); \
- (CURRENT_ENTRY) = &(EMC)->entries[srch_hash__ & EM_FLOW_HASH_MASK], \
- i__ < EM_FLOW_HASH_SEGS; \
- i__++, srch_hash__ >>= EM_FLOW_HASH_SHIFT)
/* Simple non-wildcarding single-priority classifier. */
@@ -912,90 +829,12 @@ static inline struct dpcls *
dp_netdev_pmd_lookup_dpcls(struct dp_netdev_pmd_thread *pmd,
odp_port_t in_port);
-static inline bool emc_entry_alive(struct emc_entry *ce);
-static void emc_clear_entry(struct emc_entry *ce);
-static void smc_clear_entry(struct smc_bucket *b, int idx);
-
static void dp_netdev_request_reconfigure(struct dp_netdev *dp);
static inline bool
pmd_perf_metrics_enabled(const struct dp_netdev_pmd_thread *pmd);
static void queue_netdev_flow_del(struct dp_netdev_pmd_thread *pmd,
struct dp_netdev_flow *flow);
-static void
-emc_cache_init(struct emc_cache *flow_cache)
-{
- int i;
-
- flow_cache->sweep_idx = 0;
- for (i = 0; i < ARRAY_SIZE(flow_cache->entries); i++) {
- flow_cache->entries[i].flow = NULL;
- flow_cache->entries[i].key.hash = 0;
- flow_cache->entries[i].key.len = sizeof(struct miniflow);
- flowmap_init(&flow_cache->entries[i].key.mf.map);
- }
-}
-
-static void
-smc_cache_init(struct smc_cache *smc_cache)
-{
- int i, j;
- for (i = 0; i < SMC_BUCKET_CNT; i++) {
- for (j = 0; j < SMC_ENTRY_PER_BUCKET; j++) {
- smc_cache->buckets[i].flow_idx[j] = UINT16_MAX;
- }
- }
-}
-
-static void
-dfc_cache_init(struct dfc_cache *flow_cache)
-{
- emc_cache_init(&flow_cache->emc_cache);
- smc_cache_init(&flow_cache->smc_cache);
-}
-
-static void
-emc_cache_uninit(struct emc_cache *flow_cache)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(flow_cache->entries); i++) {
- emc_clear_entry(&flow_cache->entries[i]);
- }
-}
-
-static void
-smc_cache_uninit(struct smc_cache *smc)
-{
- int i, j;
-
- for (i = 0; i < SMC_BUCKET_CNT; i++) {
- for (j = 0; j < SMC_ENTRY_PER_BUCKET; j++) {
- smc_clear_entry(&(smc->buckets[i]), j);
- }
- }
-}
-
-static void
-dfc_cache_uninit(struct dfc_cache *flow_cache)
-{
- smc_cache_uninit(&flow_cache->smc_cache);
- emc_cache_uninit(&flow_cache->emc_cache);
-}
-
-/* Check and clear dead flow references slowly (one entry at each
- * invocation). */
-static void
-emc_cache_slow_sweep(struct emc_cache *flow_cache)
-{
- struct emc_entry *entry = &flow_cache->entries[flow_cache->sweep_idx];
-
- if (!emc_entry_alive(entry)) {
- emc_clear_entry(entry);
- }
- flow_cache->sweep_idx = (flow_cache->sweep_idx + 1) & EM_FLOW_HASH_MASK;
-}
-
/* Updates the time in PMD threads context and should be called in three cases:
*
* 1. PMD structure initialization:
@@ -3181,12 +3020,6 @@ smc_entry_get(struct dp_netdev_pmd_thread *pmd, const uint32_t hash)
return NULL;
}
-static void
-smc_clear_entry(struct smc_bucket *b, int idx)
-{
- b->flow_idx[idx] = UINT16_MAX;
-}
-
/* Insert the flow_table index into SMC. Insertion may fail when 1) SMC is
* turned off, 2) the flow_table index is larger than uint16_t can handle.
* If there is already an SMC entry having same signature, the index will be
--
2.17.1
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