User application is advocated to set the newly introduced union field
mbuf->hash.usr as flow id, which is uint32_t.
With introduction of in_flight_bitmask, the whole 32 bits of tag can
be used.
Further more, this patch fixed the integer overflow when finding the
matched tags.
Note that currently librte_distributor supports up to 64 worker
threads. If more workers are needed, the size of in_flight_bitmask and
the algorithm of finding matched tag must be revised.
Signed-off-by: Qinglai Xiao <jigsaw at gmail.com>
---
app/test/test_distributor.c | 18 ++++++------
app/test/test_distributor_perf.c | 4 +-
lib/librte_distributor/rte_distributor.c | 45 +++++++++++++++++++++--------
lib/librte_distributor/rte_distributor.h | 3 ++
lib/librte_mbuf/rte_mbuf.h | 1 +
5 files changed, 47 insertions(+), 24 deletions(-)
diff --git a/app/test/test_distributor.c b/app/test/test_distributor.c
index ce06436..9e8c06d 100644
--- a/app/test/test_distributor.c
+++ b/app/test/test_distributor.c
@@ -120,7 +120,7 @@ sanity_test(struct rte_distributor *d, struct rte_mempool
*p)
/* now set all hash values in all buffers to zero, so all pkts go to the
* one worker thread */
for (i = 0; i < BURST; i++)
- bufs[i]->hash.rss = 0;
+ bufs[i]->hash.usr = 0;
rte_distributor_process(d, bufs, BURST);
rte_distributor_flush(d);
@@ -142,7 +142,7 @@ sanity_test(struct rte_distributor *d, struct rte_mempool
*p)
if (rte_lcore_count() >= 3) {
clear_packet_count();
for (i = 0; i < BURST; i++)
- bufs[i]->hash.rss = (i & 1) << 8;
+ bufs[i]->hash.usr = (i & 1) << 8;
rte_distributor_process(d, bufs, BURST);
rte_distributor_flush(d);
@@ -167,7 +167,7 @@ sanity_test(struct rte_distributor *d, struct rte_mempool
*p)
* so load gets distributed */
clear_packet_count();
for (i = 0; i < BURST; i++)
- bufs[i]->hash.rss = i;
+ bufs[i]->hash.usr = i;
rte_distributor_process(d, bufs, BURST);
rte_distributor_flush(d);
@@ -199,7 +199,7 @@ sanity_test(struct rte_distributor *d, struct rte_mempool
*p)
return -1;
}
for (i = 0; i < BIG_BATCH; i++)
- many_bufs[i]->hash.rss = i << 2;
+ many_bufs[i]->hash.usr = i << 2;
for (i = 0; i < BIG_BATCH/BURST; i++) {
rte_distributor_process(d, &many_bufs[i*BURST], BURST);
@@ -280,7 +280,7 @@ sanity_test_with_mbuf_alloc(struct rte_distributor *d,
struct rte_mempool *p)
while (rte_mempool_get_bulk(p, (void *)bufs, BURST) < 0)
rte_distributor_process(d, NULL, 0);
for (j = 0; j < BURST; j++) {
- bufs[j]->hash.rss = (i+j) << 1;
+ bufs[j]->hash.usr = (i+j) << 1;
rte_mbuf_refcnt_set(bufs[j], 1);
}
@@ -359,7 +359,7 @@ sanity_test_with_worker_shutdown(struct rte_distributor *d,
/* now set all hash values in all buffers to zero, so all pkts go to the
* one worker thread */
for (i = 0; i < BURST; i++)
- bufs[i]->hash.rss = 0;
+ bufs[i]->hash.usr = 0;
rte_distributor_process(d, bufs, BURST);
/* at this point, we will have processed some packets and have a full
@@ -372,7 +372,7 @@ sanity_test_with_worker_shutdown(struct rte_distributor *d,
return -1;
}
for (i = 0; i < BURST; i++)
- bufs[i]->hash.rss = 0;
+ bufs[i]->hash.usr = 0;
/* get worker zero to quit */
zero_quit = 1;
@@ -416,7 +416,7 @@ test_flush_with_worker_shutdown(struct rte_distributor *d,
/* now set all hash values in all buffers to zero, so all pkts go to the
* one worker thread */
for (i = 0; i < BURST; i++)
- bufs[i]->hash.rss = 0;
+ bufs[i]->hash.usr = 0;
rte_distributor_process(d, bufs, BURST);
/* at this point, we will have processed some packets and have a full
@@ -488,7 +488,7 @@ quit_workers(struct rte_distributor *d, struct rte_mempool
*p)
zero_quit = 0;
quit = 1;
for (i = 0; i < num_workers; i++)
- bufs[i]->hash.rss = i << 1;
+ bufs[i]->hash.usr = i << 1;
rte_distributor_process(d, bufs, num_workers);
rte_mempool_put_bulk(p, (void *)bufs, num_workers);
diff --git a/app/test/test_distributor_perf.c b/app/test/test_distributor_perf.c
index b04864c..48ee344 100644
--- a/app/test/test_distributor_perf.c
+++ b/app/test/test_distributor_perf.c
@@ -159,7 +159,7 @@ perf_test(struct rte_distributor *d, struct rte_mempool *p)
}
/* ensure we have different hash value for each pkt */
for (i = 0; i < BURST; i++)
- bufs[i]->hash.rss = i;
+ bufs[i]->hash.usr = i;
start = rte_rdtsc();
for (i = 0; i < (1<<ITER_POWER); i++)
@@ -198,7 +198,7 @@ quit_workers(struct rte_distributor *d, struct rte_mempool
*p)
quit = 1;
for (i = 0; i < num_workers; i++)
- bufs[i]->hash.rss = i << 1;
+ bufs[i]->hash.usr = i << 1;
rte_distributor_process(d, bufs, num_workers);
rte_mempool_put_bulk(p, (void *)bufs, num_workers);
diff --git a/lib/librte_distributor/rte_distributor.c
b/lib/librte_distributor/rte_distributor.c
index 656ee5c..a84ea97 100644
--- a/lib/librte_distributor/rte_distributor.c
+++ b/lib/librte_distributor/rte_distributor.c
@@ -92,7 +92,13 @@ struct rte_distributor {
unsigned num_workers; /**< Number of workers polling */
uint32_t in_flight_tags[RTE_MAX_LCORE];
- /**< Tracks the tag being processed per core, 0 == no pkt */
+ /**< Tracks the tag being processed per core */
+ uint64_t in_flight_bitmask;
+ /**< on/off bits for in-flight tags.
+ * Note that if RTE_MAX_LCORE is larger than 64 then
+ * the bitmask has to expand.
+ */
+
struct rte_distributor_backlog backlog[RTE_MAX_LCORE];
union rte_distributor_buffer bufs[RTE_MAX_LCORE];
@@ -189,6 +195,7 @@ static inline void
handle_worker_shutdown(struct rte_distributor *d, unsigned wkr)
{
d->in_flight_tags[wkr] = 0;
+ d->in_flight_bitmask &= ~(1UL << wkr);
d->bufs[wkr].bufptr64 = 0;
if (unlikely(d->backlog[wkr].count != 0)) {
/* On return of a packet, we need to move the
@@ -211,7 +218,10 @@ handle_worker_shutdown(struct rte_distributor *d, unsigned
wkr)
pkts[i] = (void *)((uintptr_t)(bl->pkts[idx] >>
RTE_DISTRIB_FLAG_BITS));
}
- /* recursive call */
+ /* recursive call.
+ * Note that the tags were set before first level call
+ * to rte_distributor_process.
+ */
rte_distributor_process(d, pkts, i);
bl->count = bl->start = 0;
}
@@ -242,6 +252,7 @@ process_returns(struct rte_distributor *d)
else {
d->bufs[wkr].bufptr64 = RTE_DISTRIB_GET_BUF;
d->in_flight_tags[wkr] = 0;
+ d->in_flight_bitmask &= ~(1UL << wkr);
}
oldbuf = data >> RTE_DISTRIB_FLAG_BITS;
} else if (data & RTE_DISTRIB_RETURN_BUF) {
@@ -284,17 +295,21 @@ rte_distributor_process(struct rte_distributor *d,
next_value = (((int64_t)(uintptr_t)next_mb)
<< RTE_DISTRIB_FLAG_BITS);
/*
- * Set the low bit on the tag, so we can guarantee that
- * we never store a tag value of zero. That means we can
- * use the zero-value to indicate that no packet is
- * being processed by a worker.
+ * User is advocated to set tag vaue for each
+ * mbuf before calling rte_distributor_process.
+ * User defined tags are used to identify flows,
+ * or sessions.
*/
- new_tag = (next_mb->hash.rss | 1);
+ new_tag = next_mb->hash.usr;
- uint32_t match = 0;
+ /*
+ * Note that if RTE_MAX_LCORE is larger than 64 then
+ * the size of match has to be expanded.
+ */
+ uint64_t match = 0;
unsigned i;
/*
- * to scan for a match use "xor" and "not" to get a 0/1
+ * To scan for a match use "xor" and "not" to get a 0/1
* value, then use shifting to merge to single "match"
* variable, where a one-bit indicates a match for the
* worker given by the bit-position
@@ -303,9 +318,11 @@ rte_distributor_process(struct rte_distributor *d,
match |= (!(d->in_flight_tags[i] ^ new_tag)
<< i);
+ /* Only turned-on bits are considered as match */
+ match &= d->in_flight_bitmask;
if (match) {
next_mb = NULL;
- unsigned worker = __builtin_ctz(match);
+ unsigned worker = __builtin_ctzl(match);
if (add_to_backlog(&d->backlog[worker],
next_value) < 0)
next_idx--;
@@ -322,6 +339,7 @@ rte_distributor_process(struct rte_distributor *d,
else {
d->bufs[wkr].bufptr64 = next_value;
d->in_flight_tags[wkr] = new_tag;
+ d->in_flight_bitmask |= (1UL << wkr);
next_mb = NULL;
}
oldbuf = data >> RTE_DISTRIB_FLAG_BITS;
@@ -379,11 +397,12 @@ rte_distributor_returned_pkts(struct rte_distributor *d,
static inline unsigned
total_outstanding(const struct rte_distributor *d)
{
- unsigned wkr, total_outstanding = 0;
+ unsigned wkr, total_outstanding;
+ total_outstanding = __builtin_popcountl(d->in_flight_bitmask);
for (wkr = 0; wkr < d->num_workers; wkr++)
- total_outstanding += d->backlog[wkr].count +
- !!(d->in_flight_tags[wkr]);
+ total_outstanding += d->backlog[wkr].count;
+
return total_outstanding;
}
diff --git a/lib/librte_distributor/rte_distributor.h
b/lib/librte_distributor/rte_distributor.h
index ec0d74a..a29c506 100644
--- a/lib/librte_distributor/rte_distributor.h
+++ b/lib/librte_distributor/rte_distributor.h
@@ -87,6 +87,9 @@ rte_distributor_create(const char *name, unsigned socket_id,
* Process a set of packets by distributing them among workers that request
* packets. The distributor will ensure that no two packets that have the
* same flow id, or tag, in the mbuf will be procesed at the same time.
+ * The user is advocated to set tag for each mbuf. If user doesn't set the
+ * tag, the tag value can be various values depending on driver implementation
+ * and configuration.
*
* This is not multi-thread safe and should only be called on a single lcore.
*
diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index e8f9bfc..f5f8658 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -185,6 +185,7 @@ struct rte_mbuf {
uint16_t id;
} fdir; /**< Filter identifier if FDIR enabled */
uint32_t sched; /**< Hierarchical scheduler */
+ uint32_t usr; /**< User defined tags. See
@rte_distributor_process */
} hash; /**< hash information */
/* second cache line - fields only used in slow path or on TX */
--
1.7.1
