[ovs-dev] [PATCH v3] ovsdb: Weak references performance fix
Rodriguez Betancourt, Esteban
estebarb at hpe.com
Wed Jul 13 17:28:51 UTC 2016
Prevents the cloning of rows with outgoing or
incoming weak references when those rows aren't
being modified.
It improves the OVSDB Server performance when
many rows with weak references are involved
in a transaction.
Signed-off-by: Esteban Rodriguez Betancourt <estebarb at hpe.com>
---
In the previous patch I forgot to update the test to use the new function name,
otherwise this patch is identical to the previous one.
include/openvswitch/list.h | 7 ++++++
ovsdb/row.h | 8 ++++---
ovsdb/transaction.c | 57 +++++++++++++++++++++++++++++++++++++++-------
tests/library.at | 4 ++--
tests/test-list.c | 41 +++++++++++++++++++++++++++++++++
5 files changed, 104 insertions(+), 13 deletions(-)
diff --git a/include/openvswitch/list.h b/include/openvswitch/list.h
index 5c2cca4..ea5b3db 100644
--- a/include/openvswitch/list.h
+++ b/include/openvswitch/list.h
@@ -288,4 +288,11 @@ ovs_list_is_short(const struct ovs_list *list)
return list->next == list->prev;
}
+/* Transplant a list into another, and resets the origin list */
+static inline void
+ovs_list_push_back_all(struct ovs_list *dst, struct ovs_list *src)
+{
+ ovs_list_splice(dst, src->next, src);
+}
+
#endif /* list.h */
diff --git a/ovsdb/row.h b/ovsdb/row.h
index b1d1edd..b38c7dd 100644
--- a/ovsdb/row.h
+++ b/ovsdb/row.h
@@ -36,9 +36,11 @@ struct ovsdb_column_set;
* ovsdb_weak_ref" structures are created for them.
*/
struct ovsdb_weak_ref {
- struct ovs_list src_node; /* In src->src_refs list. */
- struct ovs_list dst_node; /* In destination row's dst_refs list. */
- struct ovsdb_row *src; /* Source row. */
+ struct ovs_list src_node; /* In src->src_refs list. */
+ struct ovs_list dst_node; /* In destination row's dst_refs list. */
+ struct ovsdb_row *src; /* Source row. */
+ struct ovsdb_table *dst_table; /* Destination table. */
+ struct uuid dst; /* Destination row uuid. */
};
/* A row in a database table. */
diff --git a/ovsdb/transaction.c b/ovsdb/transaction.c
index 9e12a62..e2a16e6 100644
--- a/ovsdb/transaction.c
+++ b/ovsdb/transaction.c
@@ -436,9 +436,48 @@ ovsdb_txn_row_commit(struct ovsdb_txn *txn OVS_UNUSED,
return NULL;
}
+static struct ovsdb_error *
+ovsdb_txn_update_weak_refs(struct ovsdb_txn *txn OVS_UNUSED,
+ struct ovsdb_txn_row *txn_row)
+{
+ struct ovsdb_weak_ref *weak, *next;
+
+ /* Remove the weak references originating in the old version of the row */
+ if (txn_row->old) {
+ LIST_FOR_EACH_SAFE (weak, next, src_node, &txn_row->old->src_refs) {
+ ovs_list_remove(&weak->src_node);
+ ovs_list_remove(&weak->dst_node);
+ free(weak);
+ }
+ }
+
+ /* Although the originating rows have the responsability of updating the
+ * weak references in the dst, is possible that some source rows aren't
+ * part of the transaction.
+ * In that situation this row needs to move the list of incoming weak
+ * references from the old row into the new one.
+ */
+ if (txn_row->old && txn_row->new) {
+ /* Move the incoming weak references from old to new */
+ ovs_list_push_back_all(&txn_row->new->dst_refs, &txn_row->old->dst_refs);
+ }
+
+ /* Insert the weak references originating in the new version of the row */
+ struct ovsdb_row *dst_row;
+ if (txn_row->new) {
+ LIST_FOR_EACH (weak, src_node, &txn_row->new->src_refs) {
+ /* dst_row MUST exist */
+ dst_row = CONST_CAST(struct ovsdb_row *,
+ ovsdb_table_get_row(weak->dst_table, &weak->dst));
+ ovs_list_insert(&dst_row->dst_refs, &weak->dst_node);
+ }
+ }
+
+ return NULL;
+}
+
static void
-add_weak_ref(struct ovsdb_txn *txn,
- const struct ovsdb_row *src_, const struct ovsdb_row *dst_)
+add_weak_ref(const struct ovsdb_row *src_, const struct ovsdb_row *dst_)
{
struct ovsdb_row *src = CONST_CAST(struct ovsdb_row *, src_);
struct ovsdb_row *dst = CONST_CAST(struct ovsdb_row *, dst_);
@@ -448,8 +487,6 @@ add_weak_ref(struct ovsdb_txn *txn,
return;
}
- dst = ovsdb_txn_row_modify(txn, dst);
-
if (!ovs_list_is_empty(&dst->dst_refs)) {
/* Omit duplicates. */
weak = CONTAINER_OF(ovs_list_back(&dst->dst_refs),
@@ -461,7 +498,10 @@ add_weak_ref(struct ovsdb_txn *txn,
weak = xmalloc(sizeof *weak);
weak->src = src;
- ovs_list_push_back(&dst->dst_refs, &weak->dst_node);
+ weak->dst_table = dst->table;
+ weak->dst = *ovsdb_row_get_uuid(dst);
+ /* The dst_refs list is updated at commit time */
+ ovs_list_init(&weak->dst_node);
ovs_list_push_back(&src->src_refs, &weak->src_node);
}
@@ -471,7 +511,7 @@ assess_weak_refs(struct ovsdb_txn *txn, struct ovsdb_txn_row *txn_row)
struct ovsdb_table *table;
struct shash_node *node;
- if (txn_row->old) {
+ if (txn_row->old && !txn_row->new) {
/* Mark rows that have weak references to 'txn_row' as modified, so
* that their weak references will get reassessed. */
struct ovsdb_weak_ref *weak, *next;
@@ -506,7 +546,7 @@ assess_weak_refs(struct ovsdb_txn *txn, struct ovsdb_txn_row *txn_row)
row = ovsdb_table_get_row(column->type.key.u.uuid.refTable,
&datum->keys[i].uuid);
if (row) {
- add_weak_ref(txn, txn_row->new, row);
+ add_weak_ref(txn_row->new, row);
i++;
} else {
if (uuid_is_zero(&datum->keys[i].uuid)) {
@@ -524,7 +564,7 @@ assess_weak_refs(struct ovsdb_txn *txn, struct ovsdb_txn_row *txn_row)
row = ovsdb_table_get_row(column->type.value.u.uuid.refTable,
&datum->values[i].uuid);
if (row) {
- add_weak_ref(txn, txn_row->new, row);
+ add_weak_ref(txn_row->new, row);
i++;
} else {
if (uuid_is_zero(&datum->values[i].uuid)) {
@@ -838,6 +878,7 @@ ovsdb_txn_commit_(struct ovsdb_txn *txn, bool durable)
/* Finalize commit. */
txn->db->run_triggers = true;
+ ovsdb_error_assert(for_each_txn_row(txn, ovsdb_txn_update_weak_refs));
ovsdb_error_assert(for_each_txn_row(txn, ovsdb_txn_row_commit));
ovsdb_txn_free(txn);
diff --git a/tests/library.at b/tests/library.at
index e5095a0..bbf1e9d 100644
--- a/tests/library.at
+++ b/tests/library.at
@@ -43,8 +43,8 @@ AT_SETUP([atomic operations])
AT_CHECK([ovstest test-atomic])
AT_CLEANUP
-AT_SETUP([linked lists])
-AT_CHECK([ovstest test-list], [0], [...
+AT_SETUP([test linked lists])
+AT_CHECK([ovstest test-list], [0], [....
])
AT_CLEANUP
diff --git a/tests/test-list.c b/tests/test-list.c
index d413f30..6f1fb05 100644
--- a/tests/test-list.c
+++ b/tests/test-list.c
@@ -185,6 +185,46 @@ test_list_for_each_pop(void)
}
}
+/* Tests the transplant of one list into another */
+static void
+test_list_push_back_all(void)
+{
+ struct ovs_list list_a, list_b;
+ struct element a, b, c, d;
+
+ a.value = 0;
+ b.value = 1;
+ c.value = 2;
+ d.value = 3;
+
+ ovs_list_init(&list_a);
+ ovs_list_init(&list_b);
+
+ ovs_list_insert(&list_a, &a.node);
+ ovs_list_insert(&list_a, &b.node);
+ ovs_list_insert(&list_b, &c.node);
+ ovs_list_insert(&list_b, &d.node);
+
+ /* Check test preconditions */
+ assert(2 == ovs_list_size(&list_a));
+ assert(2 == ovs_list_size(&list_b));
+
+ /* Perform transplant */
+ ovs_list_push_back_all(&list_a, &list_b);
+
+ /* Check expected result */
+ assert(4 == ovs_list_size(&list_a));
+ assert(0 == ovs_list_size(&list_b));
+
+ struct element *node;
+ int n = 0;
+ LIST_FOR_EACH(node, node, &list_a) {
+ assert(n == node->value);
+ n++;
+ }
+ assert(n == 4);
+}
+
static void
run_test(void (*function)(void))
{
@@ -198,6 +238,7 @@ test_list_main(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
run_test(test_list_construction);
run_test(test_list_for_each_safe);
run_test(test_list_for_each_pop);
+ run_test(test_list_push_back_all);
printf("\n");
}
--
2.7.4
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