Miniflows can nowadays be dynamically allocated to different inline
sizes, as done by lib/classifier.c, but this had not been documented
at the struct miniflow definition.
Also, MINI_N_INLINE had a different value for 32-bit and 64-bit builds
due to a historical reason. Now we use 8 for both.
Finally, use change the storage type of 'values_inline' to uint8_t, as
uint64_t looks kind of wide for a boolean, even though we intend the
bit be carved out from the uint64_t where 'map' resides.
Suggested-by: Ben Pfaff <b...@nicira.com>
Signed-off-by: Jarno Rajahalme <jrajaha...@nicira.com>
---
lib/flow.c | 3 ++-
lib/flow.h | 16 +++++++++++++---
2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/lib/flow.c b/lib/flow.c
index bef2f27..d322ac2 100644
--- a/lib/flow.c
+++ b/lib/flow.c
@@ -1715,7 +1715,8 @@ miniflow_clone_inline(struct miniflow *dst, const struct
miniflow *src,
/* Initializes 'dst' with the data in 'src', destroying 'src'.
* The caller must eventually free 'dst' with miniflow_destroy().
* 'dst' must be regularly sized miniflow, but 'src' can have
- * larger than default inline values. */
+ * storage for more than the default MINI_N_INLINE inline
+ * values. */
void
miniflow_move(struct miniflow *dst, struct miniflow *src)
{
diff --git a/lib/flow.h b/lib/flow.h
index 3b8d24d..2891d60 100644
--- a/lib/flow.h
+++ b/lib/flow.h
@@ -346,7 +346,10 @@ bool flow_equal_except(const struct flow *a, const struct
flow *b,
/* Compressed flow. */
-#define MINI_N_INLINE (sizeof(void *) == 4 ? 7 : 8)
+/* Number of 32-bit words present in struct miniflow. */
+#define MINI_N_INLINE 8
+
+/* Maximum number of 32-bit words supported. */
BUILD_ASSERT_DECL(FLOW_U32S <= 63);
/* A sparse representation of a "struct flow".
@@ -367,6 +370,11 @@ BUILD_ASSERT_DECL(FLOW_U32S <= 63);
* the first element of the values array, the next 1-bit is in the next array
* element, and so on.
*
+ * MINI_N_INLINE is the default number of inline words. When a miniflow is
+ * dynamically allocated the actual amount of inline storage may be different.
+ * In that case 'inline_values' contains storage at least for the number
+ * of words indicated by 'map' (one uint32_t for each 1-bit in the map).
+ *
* Elements in values array are allowed to be zero. This is useful for "struct
* minimatch", for which ensuring that the miniflow and minimask members have
* same 'map' allows optimization. This allowance applies only to a miniflow
@@ -375,12 +383,14 @@ BUILD_ASSERT_DECL(FLOW_U32S <= 63);
*/
struct miniflow {
uint64_t map:63;
- uint64_t values_inline:1;
+ uint8_t values_inline:1;
union {
uint32_t *offline_values;
- uint32_t inline_values[MINI_N_INLINE];
+ uint32_t inline_values[MINI_N_INLINE]; /* Minimum inline size. */
};
};
+BUILD_ASSERT_DECL(sizeof(struct miniflow)
+ == sizeof(uint64_t) + MINI_N_INLINE * sizeof(uint32_t));
#define MINIFLOW_VALUES_SIZE(COUNT) ((COUNT) * sizeof(uint32_t))
--
1.7.10.4
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