Optimized thread-safe counters.
- Each vlib_[simple|combined]_counter_main_t consists of a single
- vector of thread-safe / atomically-updated u64 counters [the
- "maxi" vector], and a (u16 **) per-thread vector [the "minis"
- vector] of narrow, per-thread counters.
-
- The idea is to drastically reduce the number of atomic operations.
- In the case of packet counts, we divide the number of atomic ops
- by 2**16, etc.
+ Each vlib_[simple|combined]_counter_main_t consists of a per-thread
+ vector of per-object counters.
+
+ The idea is to drastically eliminate atomic operations.
*/
+/** 64bit counters */
+typedef u64 counter_t;
+
/** A collection of simple counters */
typedef struct
{
- u16 **minis; /**< Per-thread u16 non-atomic counters */
- u64 *maxi; /**< Shared wide counters */
- u64 *value_at_last_clear; /**< Counter values as of last clear. */
- u64 *value_at_last_serialize; /**< Values as of last serialize. */
+ counter_t **counters; /**< Per-thread u64 non-atomic counters */
+ counter_t *value_at_last_serialize; /**< Values as of last serialize. */
u32 last_incremental_serialize_index; /**< Last counter index
serialized incrementally. */
char *name; /**< The counter collection's name. */
} vlib_simple_counter_main_t;
+/** The number of counters (not the number of per-thread counters) */
+u32 vlib_simple_counter_n_counters (const vlib_simple_counter_main_t * cm);
+
/** Increment a simple counter
@param cm - (vlib_simple_counter_main_t *) simple counter main pointer
@param cpu_index - (u32) the current cpu index
@param index - (u32) index of the counter to increment
- @param increment - (u32) quantitiy to add to the counter
+ @param increment - (u64) quantitiy to add to the counter
*/
always_inline void
vlib_increment_simple_counter (vlib_simple_counter_main_t * cm,
- u32 cpu_index, u32 index, u32 increment)
+ u32 cpu_index, u32 index, u64 increment)
{
- u16 *my_minis;
- u16 *mini;
- u32 old, new;
-
- my_minis = cm->minis[cpu_index];
- mini = vec_elt_at_index (my_minis, index);
- old = mini[0];
- new = old + increment;
- mini[0] = new;
+ counter_t *my_counters;
- if (PREDICT_FALSE (mini[0] != new))
- {
- __sync_fetch_and_add (&cm->maxi[index], new);
- my_minis[index] = 0;
- }
+ my_counters = cm->counters[cpu_index];
+ my_counters[index] += increment;
}
/** Get the value of a simple counter
- Scrapes the entire set of mini counters. Innacurate unless
+ Scrapes the entire set of per-thread counters. Innacurate unless
worker threads which might increment the counter are
barrier-synchronized
@param index - (u32) index of the counter to fetch
@returns - (u64) current counter value
*/
-always_inline u64
+always_inline counter_t
vlib_get_simple_counter (vlib_simple_counter_main_t * cm, u32 index)
{
- u16 *my_minis, *mini;
- u64 v;
+ counter_t *my_counters;
+ counter_t v;
int i;
- ASSERT (index < vec_len (cm->maxi));
+ ASSERT (index < vlib_simple_counter_n_counters (cm));
v = 0;
- for (i = 0; i < vec_len (cm->minis); i++)
+ for (i = 0; i < vec_len (cm->counters); i++)
{
- my_minis = cm->minis[i];
- mini = vec_elt_at_index (my_minis, index);
- v += mini[0];
- }
-
- v += cm->maxi[index];
-
- if (index < vec_len (cm->value_at_last_clear))
- {
- ASSERT (v >= cm->value_at_last_clear[index]);
- v -= cm->value_at_last_clear[index];
+ my_counters = cm->counters[i];
+ v += my_counters[index];
}
return v;
always_inline void
vlib_zero_simple_counter (vlib_simple_counter_main_t * cm, u32 index)
{
- u16 *my_minis;
+ counter_t *my_counters;
int i;
- ASSERT (index < vec_len (cm->maxi));
+ ASSERT (index < vlib_simple_counter_n_counters (cm));
- for (i = 0; i < vec_len (cm->minis); i++)
+ for (i = 0; i < vec_len (cm->counters); i++)
{
- my_minis = cm->minis[i];
- my_minis[index] = 0;
+ my_counters = cm->counters[i];
+ my_counters[index] = 0;
}
-
- cm->maxi[index] = 0;
-
- if (index < vec_len (cm->value_at_last_clear))
- cm->value_at_last_clear[index] = 0;
}
/** Combined counter to hold both packets and byte differences.
*/
typedef struct
{
- u64 packets; /**< packet counter */
- u64 bytes; /**< byte counter */
+ counter_t packets; /**< packet counter */
+ counter_t bytes; /**< byte counter */
} vlib_counter_t;
/** Add two combined counters, results in the first counter
a->packets = a->bytes = 0;
}
-/** Mini combined counter */
-typedef struct
-{
- u16 packets; /**< Packet count */
- i16 bytes; /**< Byte count */
-} vlib_mini_counter_t;
-
/** A collection of combined counters */
typedef struct
{
- vlib_mini_counter_t **minis; /**< Per-thread u16 non-atomic counter pairs */
- vlib_counter_t *maxi; /**< Shared wide counter pairs */
- vlib_counter_t *value_at_last_clear; /**< Counter values as of last clear. */
+ vlib_counter_t **counters; /**< Per-thread u64 non-atomic counter pairs */
vlib_counter_t *value_at_last_serialize; /**< Counter values as of last serialize. */
u32 last_incremental_serialize_index; /**< Last counter index serialized incrementally. */
char *name; /**< The counter collection's name. */
} vlib_combined_counter_main_t;
+/** The number of counters (not the number of per-thread counters) */
+u32 vlib_combined_counter_n_counters (const vlib_combined_counter_main_t *
+ cm);
+
/** Clear a collection of simple counters
@param cm - (vlib_simple_counter_main_t *) collection to clear
*/
@param cm - (vlib_combined_counter_main_t *) comined counter main pointer
@param cpu_index - (u32) the current cpu index
@param index - (u32) index of the counter to increment
- @param packet_increment - (u32) number of packets to add to the counter
- @param byte_increment - (u32) number of bytes to add to the counter
+ @param packet_increment - (u64) number of packets to add to the counter
+ @param byte_increment - (u64) number of bytes to add to the counter
*/
always_inline void
vlib_increment_combined_counter (vlib_combined_counter_main_t * cm,
u32 cpu_index,
- u32 index,
- u32 packet_increment, u32 byte_increment)
+ u32 index, u64 n_packets, u64 n_bytes)
{
- vlib_mini_counter_t *my_minis, *mini;
- u32 old_packets, new_packets;
- i32 old_bytes, new_bytes;
-
- /* Use this CPU's mini counter array */
- my_minis = cm->minis[cpu_index];
-
- mini = vec_elt_at_index (my_minis, index);
- old_packets = mini->packets;
- old_bytes = mini->bytes;
-
- new_packets = old_packets + packet_increment;
- new_bytes = old_bytes + byte_increment;
-
- mini->packets = new_packets;
- mini->bytes = new_bytes;
-
- /* Bytes always overflow before packets.. */
- if (PREDICT_FALSE (mini->bytes != new_bytes))
- {
- vlib_counter_t *maxi = vec_elt_at_index (cm->maxi, index);
+ vlib_counter_t *my_counters;
- __sync_fetch_and_add (&maxi->packets, new_packets);
- __sync_fetch_and_add (&maxi->bytes, new_bytes);
+ /* Use this CPU's counter array */
+ my_counters = cm->counters[cpu_index];
- mini->packets = 0;
- mini->bytes = 0;
- }
+ my_counters[index].packets += n_packets;
+ my_counters[index].bytes += n_bytes;
}
-#define vlib_prefetch_combined_counter(_cm, _cpu_index, _index) \
-{ \
- vlib_mini_counter_t *_cpu_minis; \
- \
- /* \
- * This CPU's mini index is assumed to already be in cache \
- */ \
- _cpu_minis = (_cm)->minis[(_cpu_index)]; \
- CLIB_PREFETCH(_cpu_minis + (_index), \
- sizeof(*_cpu_minis), \
- STORE); \
+/** Pre-fetch a per-thread combined counter for the given object index */
+always_inline void
+vlib_prefetch_combined_counter (const vlib_combined_counter_main_t * cm,
+ u32 cpu_index, u32 index)
+{
+ vlib_counter_t *cpu_counters;
+
+ /*
+ * This CPU's index is assumed to already be in cache
+ */
+ cpu_counters = cm->counters[cpu_index];
+ CLIB_PREFETCH (cpu_counters + index, CLIB_CACHE_LINE_BYTES, STORE);
}
/** Get the value of a combined counter, never called in the speed path
- Scrapes the entire set of mini counters. Innacurate unless
+ Scrapes the entire set of per-thread counters. Innacurate unless
worker threads which might increment the counter are
barrier-synchronized
*/
static inline void
-vlib_get_combined_counter (vlib_combined_counter_main_t * cm,
+vlib_get_combined_counter (const vlib_combined_counter_main_t * cm,
u32 index, vlib_counter_t * result)
{
- vlib_mini_counter_t *my_minis, *mini;
- vlib_counter_t *maxi;
+ vlib_counter_t *my_counters, *counter;
int i;
result->packets = 0;
result->bytes = 0;
- for (i = 0; i < vec_len (cm->minis); i++)
+ for (i = 0; i < vec_len (cm->counters); i++)
{
- my_minis = cm->minis[i];
+ my_counters = cm->counters[i];
- mini = vec_elt_at_index (my_minis, index);
- result->packets += mini->packets;
- result->bytes += mini->bytes;
+ counter = vec_elt_at_index (my_counters, index);
+ result->packets += counter->packets;
+ result->bytes += counter->bytes;
}
-
- maxi = vec_elt_at_index (cm->maxi, index);
- result->packets += maxi->packets;
- result->bytes += maxi->bytes;
-
- if (index < vec_len (cm->value_at_last_clear))
- vlib_counter_sub (result, &cm->value_at_last_clear[index]);
}
/** Clear a combined counter
- Clears the set of per-thread u16 counters, and the shared vlib_counter_t
+ Clears the set of per-thread counters.
@param cm - (vlib_combined_counter_main_t *) combined counter main pointer
@param index - (u32) index of the counter to clear
always_inline void
vlib_zero_combined_counter (vlib_combined_counter_main_t * cm, u32 index)
{
- vlib_mini_counter_t *mini, *my_minis;
+ vlib_counter_t *my_counters, *counter;
int i;
- for (i = 0; i < vec_len (cm->minis); i++)
+ for (i = 0; i < vec_len (cm->counters); i++)
{
- my_minis = cm->minis[i];
+ my_counters = cm->counters[i];
- mini = vec_elt_at_index (my_minis, index);
- mini->packets = 0;
- mini->bytes = 0;
+ counter = vec_elt_at_index (my_counters, index);
+ counter->packets = 0;
+ counter->bytes = 0;
}
-
- vlib_counter_zero (&cm->maxi[index]);
- if (index < vec_len (cm->value_at_last_clear))
- vlib_counter_zero (&cm->value_at_last_clear[index]);
}
/** validate a simple counter
Code Review / vpp.git / blobdiff