memif: do not mask head and tail pointers
Change-Id: Ie849ab713ff086187c18a91ab32e58207fe94033
Signed-off-by: Damjan Marion <damarion@cisco.com>
Signed-off-by: Jakub Grajciar <Jakub.Grajciar@pantheon.tech>
diff --git a/extras/libmemif/src/libmemif.h b/extras/libmemif/src/libmemif.h
index da48edd..3fc0648 100644
--- a/extras/libmemif/src/libmemif.h
+++ b/extras/libmemif/src/libmemif.h
@@ -73,6 +73,7 @@
MEMIF_ERR_DISCONNECTED, /*!< peer interface disconnected */
MEMIF_ERR_UNKNOWN_MSG, /*!< unknown message type */
MEMIF_ERR_POLL_CANCEL, /*!< memif_poll_event() was cancelled */
+ MEMIF_ERR_MAX_RING, /*!< too large ring size */
} memif_err_t;
/**
diff --git a/extras/libmemif/src/main.c b/extras/libmemif/src/main.c
index 39c18f2..2e2602e 100644
--- a/extras/libmemif/src/main.c
+++ b/extras/libmemif/src/main.c
@@ -54,7 +54,7 @@
/* private structs and functions */
#include <memif_private.h>
-#define ERRLIST_LEN 37
+#define ERRLIST_LEN 38
#define MAX_ERRBUF_LEN 256
#if __x86_x64__
@@ -142,7 +142,9 @@
/* MEMIF_ERR_UNKNOWN_MSG */
"Unknown message type received on control channel. (internal error)",
/* MEMIF_ERR_POLL_CANCEL */
- "Memif event polling was canceled."
+ "Memif event polling was canceled.",
+ /* MEMIF_ERR_MAX_RING */
+ "Maximum log2 ring size is 15"
};
#define MEMIF_ERR_UNDEFINED "undefined error"
@@ -201,7 +203,7 @@
return MEMIF_ERR_PROC_FILE_LIMIT;
if (err_code == ENOMEM)
return MEMIF_ERR_NOMEM;
-/* connection refused if master dows not exist
+/* connection refused if master does not exist
this error would spam the user until master was created */
if (err_code == ECONNREFUSED)
return MEMIF_ERR_SUCCESS;
@@ -560,6 +562,11 @@
if (args->log2_ring_size == 0)
args->log2_ring_size = MEMIF_DEFAULT_LOG2_RING_SIZE;
+ else if (args->log2_ring_size > MEMIF_MAX_LOG2_RING_SIZE)
+ {
+ err = MEMIF_ERR_MAX_RING;
+ goto error;
+ }
if (args->buffer_size == 0)
args->buffer_size = MEMIF_DEFAULT_BUFFER_SIZE;
if (args->num_s2m_rings == 0)
@@ -1390,18 +1397,15 @@
memif_buffer_t *b0, *b1;
uint8_t chain_buf = 1;
uint16_t mask = (1 << mq->log2_ring_size) - 1;
+ uint16_t head = ring->head;
+ uint16_t tail = ring->tail;
uint16_t s0, s1, ns;
*count_out = 0;
int i, err = MEMIF_ERR_SUCCESS; /* 0 */
- if (ring->tail > ring->head)
- ns = ring->tail - ring->head;
- else
- ns = (1 << mq->log2_ring_size) - ring->head + ring->tail;
+ ns = (1 << mq->log2_ring_size) - head + tail;
- /* (head == tail) ? receive function will asume that no packets are available */
- ns -= 1;
-
+ /* calculate number of chain buffers */
if (size > ring->desc[0].buffer_length)
{
chain_buf = size / ring->desc[s0].buffer_length;
@@ -1422,8 +1426,8 @@
b0 = (bufs + *count_out);
b1 = (bufs + *count_out + 1);
- b0->desc_index = s0;
- b1->desc_index = s1;
+ b0->desc_index = head + mq->alloc_bufs;
+ b1->desc_index = head + mq->alloc_bufs + chain_buf;
ring->desc[s0].flags = 0;
ring->desc[s1].flags = 0;
b0->buffer_len = ring->desc[s0].buffer_length * chain_buf;
@@ -1453,7 +1457,7 @@
if (chain_buf > ns)
break;
- b0->desc_index = s0;
+ b0->desc_index = head + mq->alloc_bufs;
ring->desc[s0].flags = 0;
b0->buffer_len = ring->desc[s0].buffer_length * chain_buf;
b0->data = c->regions->shm + ring->desc[s0].offset;
@@ -1527,7 +1531,7 @@
if ((b1->buffer_len % ring->desc[b1->desc_index].buffer_length) !=
0)
chain_buf1++;
- tail = (b1->desc_index + chain_buf1) & mask;
+ tail = b1->desc_index + chain_buf1;
b0->data = NULL;
b1->data = NULL;
@@ -1539,7 +1543,7 @@
chain_buf0 = b0->buffer_len / ring->desc[b0->desc_index].buffer_length;
if ((b0->buffer_len % ring->desc[b0->desc_index].buffer_length) != 0)
chain_buf0++;
- tail = (b0->desc_index + chain_buf0) & mask;
+ tail = b0->desc_index + chain_buf0;
b0->data = NULL;
count--;
@@ -1808,10 +1812,7 @@
if (head == mq->last_head)
return 0;
- if (head > mq->last_head)
- ns = head - mq->last_head;
- else
- ns = (1 << mq->log2_ring_size) - mq->last_head + head;
+ ns = head - mq->last_head;
while (ns && count)
{
@@ -1821,62 +1822,62 @@
b1 = (bufs + curr_buf + 1);
b0->desc_index = mq->last_head;
- b0->data = memif_get_buffer (conn, ring, mq->last_head);
- b0->data_len = ring->desc[mq->last_head].length;
- b0->buffer_len = ring->desc[mq->last_head].buffer_length;
+ b0->data = memif_get_buffer (conn, ring, mq->last_head & mask);
+ b0->data_len = ring->desc[mq->last_head & mask].length;
+ b0->buffer_len = ring->desc[mq->last_head & mask].buffer_length;
#ifdef MEMIF_DBG_SHM
i = 0;
print_bytes (b0->data +
- ring->desc[b0->desc_index].buffer_length * i++,
- ring->desc[b0->desc_index].buffer_length, DBG_TX_BUF);
+ ring->desc[b0->desc_index & mask].buffer_length * i++,
+ ring->desc[b0->desc_index & mask].buffer_length, DBG_TX_BUF);
#endif /* MEMIF_DBG_SHM */
ns--;
*rx += 1;
- while (ring->desc[mq->last_head].flags & MEMIF_DESC_FLAG_NEXT)
+ while (ring->desc[mq->last_head & mask].flags & MEMIF_DESC_FLAG_NEXT)
{
- ring->desc[mq->last_head].flags &= ~MEMIF_DESC_FLAG_NEXT;
- mq->last_head = (mq->last_head + 1) & mask;
- b0->data_len += ring->desc[mq->last_head].length;
- b0->buffer_len += ring->desc[mq->last_head].buffer_length;
+ ring->desc[mq->last_head & mask].flags &= ~MEMIF_DESC_FLAG_NEXT;
+ mq->last_head++;
+ b0->data_len += ring->desc[mq->last_head & mask].length;
+ b0->buffer_len += ring->desc[mq->last_head & mask].buffer_length;
#ifdef MEMIF_DBG_SHM
print_bytes (b0->data +
- ring->desc[b0->desc_index].buffer_length * i++,
- ring->desc[b0->desc_index].buffer_length,
+ ring->desc[b0->desc_index & mask].buffer_length * i++,
+ ring->desc[b0->desc_index & mask].buffer_length,
DBG_TX_BUF);
#endif /* MEMIF_DBG_SHM */
ns--;
*rx += 1;
}
- mq->last_head = (mq->last_head + 1) & mask;
+ mq->last_head++;
b1->desc_index = mq->last_head;
- b1->data = memif_get_buffer (conn, ring, mq->last_head);
- b1->data_len = ring->desc[mq->last_head].length;
- b1->buffer_len = ring->desc[mq->last_head].buffer_length;
+ b1->data = memif_get_buffer (conn, ring, mq->last_head & mask);
+ b1->data_len = ring->desc[mq->last_head & mask].length;
+ b1->buffer_len = ring->desc[mq->last_head & mask].buffer_length;
#ifdef MEMIF_DBG_SHM
i = 0;
print_bytes (b1->data +
- ring->desc[b1->desc_index].buffer_length * i++,
- ring->desc[b1->desc_index].buffer_length, DBG_TX_BUF);
+ ring->desc[b1->desc_index & mask].buffer_length * i++,
+ ring->desc[b1->desc_index & mask].buffer_length, DBG_TX_BUF);
#endif /* MEMIF_DBG_SHM */
ns--;
*rx += 1;
- while (ring->desc[mq->last_head].flags & MEMIF_DESC_FLAG_NEXT)
+ while (ring->desc[mq->last_head & mask].flags & MEMIF_DESC_FLAG_NEXT)
{
- ring->desc[mq->last_head].flags &= ~MEMIF_DESC_FLAG_NEXT;
- mq->last_head = (mq->last_head + 1) & mask;
- b1->data_len += ring->desc[mq->last_head].length;
- b1->buffer_len += ring->desc[mq->last_head].buffer_length;
+ ring->desc[mq->last_head & mask].flags &= ~MEMIF_DESC_FLAG_NEXT;
+ mq->last_head++;
+ b1->data_len += ring->desc[mq->last_head & mask].length;
+ b1->buffer_len += ring->desc[mq->last_head & mask].buffer_length;
#ifdef MEMIF_DBG_SHM
print_bytes (b1->data +
- ring->desc[b1->desc_index].buffer_length * i++,
- ring->desc[b1->desc_index].buffer_length,
+ ring->desc[b1->desc_index & mask].buffer_length * i++,
+ ring->desc[b1->desc_index & mask].buffer_length,
DBG_TX_BUF);
#endif /* MEMIF_DBG_SHM */
ns--;
*rx += 1;
}
- mq->last_head = (mq->last_head + 1) & mask;
+ mq->last_head++;
count -= 2;
curr_buf += 2;
@@ -1884,33 +1885,33 @@
b0 = (bufs + curr_buf);
b0->desc_index = mq->last_head;
- b0->data = memif_get_buffer (conn, ring, mq->last_head);
- b0->data_len = ring->desc[mq->last_head].length;
- b0->buffer_len = ring->desc[mq->last_head].buffer_length;
+ b0->data = memif_get_buffer (conn, ring, mq->last_head & mask);
+ b0->data_len = ring->desc[mq->last_head & mask].length;
+ b0->buffer_len = ring->desc[mq->last_head & mask].buffer_length;
#ifdef MEMIF_DBG_SHM
i = 0;
print_bytes (b0->data +
- ring->desc[b0->desc_index].buffer_length * i++,
- ring->desc[b0->desc_index].buffer_length, DBG_TX_BUF);
+ ring->desc[b0->desc_index & mask].buffer_length * i++,
+ ring->desc[b0->desc_index & mask].buffer_length, DBG_TX_BUF);
#endif /* MEMIF_DBG_SHM */
ns--;
*rx += 1;
- while (ring->desc[mq->last_head].flags & MEMIF_DESC_FLAG_NEXT)
+ while (ring->desc[mq->last_head & mask].flags & MEMIF_DESC_FLAG_NEXT)
{
- ring->desc[mq->last_head].flags &= ~MEMIF_DESC_FLAG_NEXT;
- mq->last_head = (mq->last_head + 1) & mask;
- b0->data_len += ring->desc[mq->last_head].length;
- b0->buffer_len += ring->desc[mq->last_head].buffer_length;
+ ring->desc[mq->last_head & mask].flags &= ~MEMIF_DESC_FLAG_NEXT;
+ mq->last_head++;
+ b0->data_len += ring->desc[mq->last_head & mask].length;
+ b0->buffer_len += ring->desc[mq->last_head & mask].buffer_length;
#ifdef MEMIF_DBG_SHM
print_bytes (b0->data +
- ring->desc[b0->desc_index].buffer_length * i++,
- ring->desc[b0->desc_index].buffer_length, DBG_TX_BUF);
+ ring->desc[b0->desc_index & mask].buffer_length * i++,
+ ring->desc[b0->desc_index & mask].buffer_length, DBG_TX_BUF);
#endif /* MEMIF_DBG_SHM */
ns--;
*rx += 1;
}
- mq->last_head = (mq->last_head + 1) & mask;
+ mq->last_head++;
count--;
curr_buf++;
diff --git a/extras/libmemif/src/memif_private.h b/extras/libmemif/src/memif_private.h
index 83962bc..c213ee6 100644
--- a/extras/libmemif/src/memif_private.h
+++ b/extras/libmemif/src/memif_private.h
@@ -40,7 +40,7 @@
#define MEMIF_MAX_M2S_RING 255
#define MEMIF_MAX_S2M_RING 255
#define MEMIF_MAX_REGION 255
-#define MEMIF_MAX_LOG2_RING_SIZE 14
+#define MEMIF_MAX_LOG2_RING_SIZE 15
#define MEMIF_MAX_FDS 512
diff --git a/src/plugins/memif/cli.c b/src/plugins/memif/cli.c
index deca27a..3d38550 100644
--- a/src/plugins/memif/cli.c
+++ b/src/plugins/memif/cli.c
@@ -76,6 +76,9 @@
if (!is_pow2 (ring_size))
return clib_error_return (0, "ring size must be power of 2");
+ if (ring_size > 32768)
+ return clib_error_return (0, "maximum ring size is 32768");
+
args.log2_ring_size = min_log2 (ring_size);
if (rx_queues > 255 || rx_queues < 1)
diff --git a/src/plugins/memif/device.c b/src/plugins/memif/device.c
index f7eb862..012c753 100644
--- a/src/plugins/memif/device.c
+++ b/src/plugins/memif/device.c
@@ -109,26 +109,28 @@
vlib_buffer_t *b0;
void *mb0;
u32 total = 0, len;
+ u16 slot = (*head) & mask;
- mb0 = memif_get_buffer (mif, ring, *head);
- ring->desc[*head].flags = 0;
+ mb0 = memif_get_buffer (mif, ring, slot);
+ ring->desc[slot].flags = 0;
do
{
b0 = vlib_get_buffer (vm, bi);
len = b0->current_length;
- if (PREDICT_FALSE (ring->desc[*head].buffer_length < (total + len)))
+ if (PREDICT_FALSE (ring->desc[slot].buffer_length < (total + len)))
{
if (PREDICT_TRUE (total))
{
- ring->desc[*head].length = total;
+ ring->desc[slot].length = total;
total = 0;
- ring->desc[*head].flags |= MEMIF_DESC_FLAG_NEXT;
- *head = (*head + 1) & mask;
- mb0 = memif_get_buffer (mif, ring, *head);
- ring->desc[*head].flags = 0;
+ ring->desc[slot].flags |= MEMIF_DESC_FLAG_NEXT;
+ (*head)++;
+ slot = (*head) & mask;
+ mb0 = memif_get_buffer (mif, ring, slot);
+ ring->desc[slot].flags = 0;
}
}
- if (PREDICT_TRUE (ring->desc[*head].buffer_length >= (total + len)))
+ if (PREDICT_TRUE (ring->desc[slot].buffer_length >= (total + len)))
{
clib_memcpy (mb0 + total, vlib_buffer_get_current (b0),
CLIB_CACHE_LINE_BYTES);
@@ -149,8 +151,8 @@
if (PREDICT_TRUE (total))
{
- ring->desc[*head].length = total;
- *head = (*head + 1) & mask;
+ ring->desc[slot].length = total;
+ (*head)++;
}
}
@@ -196,34 +198,18 @@
head = ring->head;
tail = ring->tail;
- if (tail > head)
- free_slots = tail - head;
- else
- free_slots = ring_size - head + tail;
+ free_slots = ring_size - head + tail;
while (n_left > 5 && free_slots > 1)
{
- if (PREDICT_TRUE (head + 5 < ring_size))
- {
- CLIB_PREFETCH (memif_get_buffer (mif, ring, head + 2),
- CLIB_CACHE_LINE_BYTES, STORE);
- CLIB_PREFETCH (memif_get_buffer (mif, ring, head + 3),
- CLIB_CACHE_LINE_BYTES, STORE);
- CLIB_PREFETCH (&ring->desc[head + 4], CLIB_CACHE_LINE_BYTES, STORE);
- CLIB_PREFETCH (&ring->desc[head + 5], CLIB_CACHE_LINE_BYTES, STORE);
- }
- else
- {
- CLIB_PREFETCH (memif_get_buffer (mif, ring, (head + 2) % mask),
- CLIB_CACHE_LINE_BYTES, STORE);
- CLIB_PREFETCH (memif_get_buffer (mif, ring, (head + 3) % mask),
- CLIB_CACHE_LINE_BYTES, STORE);
- CLIB_PREFETCH (&ring->desc[(head + 4) % mask],
- CLIB_CACHE_LINE_BYTES, STORE);
- CLIB_PREFETCH (&ring->desc[(head + 5) % mask],
- CLIB_CACHE_LINE_BYTES, STORE);
- }
-
+ CLIB_PREFETCH (memif_get_buffer (mif, ring, (head + 2) & mask),
+ CLIB_CACHE_LINE_BYTES, STORE);
+ CLIB_PREFETCH (memif_get_buffer (mif, ring, (head + 3) & mask),
+ CLIB_CACHE_LINE_BYTES, STORE);
+ CLIB_PREFETCH (&ring->desc[(head + 4) & mask], CLIB_CACHE_LINE_BYTES,
+ STORE);
+ CLIB_PREFETCH (&ring->desc[(head + 5) & mask], CLIB_CACHE_LINE_BYTES,
+ STORE);
memif_prefetch_buffer_and_data (vm, buffers[2]);
memif_prefetch_buffer_and_data (vm, buffers[3]);
diff --git a/src/plugins/memif/node.c b/src/plugins/memif/node.c
index 8190441..74b2389 100644
--- a/src/plugins/memif/node.c
+++ b/src/plugins/memif/node.c
@@ -132,7 +132,7 @@
while (*num_slots)
{
- data_len = ring->desc[mq->last_head].length;
+ data_len = ring->desc[mq->last_head & mask].length;
while (data_len && (*n_free_bufs))
{
/* get empty buffer */
@@ -161,7 +161,7 @@
bytes_to_copy =
data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
b->current_data = 0;
- mb = memif_get_buffer (mif, ring, mq->last_head);
+ mb = memif_get_buffer (mif, ring, mq->last_head & mask);
clib_memcpy (vlib_buffer_get_current (b), mb + offset,
CLIB_CACHE_LINE_BYTES);
if (bytes_to_copy > CLIB_CACHE_LINE_BYTES)
@@ -191,10 +191,10 @@
}
last_head = mq->last_head;
/* Advance to next descriptor */
- mq->last_head = (mq->last_head + 1) & mask;
+ mq->last_head++;
offset = 0;
(*num_slots)--;
- if ((ring->desc[last_head].flags & MEMIF_DESC_FLAG_NEXT) == 0)
+ if ((ring->desc[last_head & mask].flags & MEMIF_DESC_FLAG_NEXT) == 0)
break;
}
@@ -269,10 +269,7 @@
if (head == mq->last_head)
return 0;
- if (head > mq->last_head)
- num_slots = head - mq->last_head;
- else
- num_slots = ring_size - mq->last_head + head;
+ num_slots = head - mq->last_head;
while (num_slots)
{
@@ -283,30 +280,16 @@
while (num_slots > 11 && n_left_to_next > 2)
{
- if (PREDICT_TRUE (mq->last_head + 5 < ring_size))
- {
- CLIB_PREFETCH (memif_get_buffer (mif, ring, mq->last_head + 2),
- CLIB_CACHE_LINE_BYTES, LOAD);
- CLIB_PREFETCH (memif_get_buffer (mif, ring, mq->last_head + 3),
- CLIB_CACHE_LINE_BYTES, LOAD);
- CLIB_PREFETCH (&ring->desc[mq->last_head + 4],
- CLIB_CACHE_LINE_BYTES, LOAD);
- CLIB_PREFETCH (&ring->desc[mq->last_head + 5],
- CLIB_CACHE_LINE_BYTES, LOAD);
- }
- else
- {
- CLIB_PREFETCH (memif_get_buffer
- (mif, ring, (mq->last_head + 2) % mask),
- CLIB_CACHE_LINE_BYTES, LOAD);
- CLIB_PREFETCH (memif_get_buffer
- (mif, ring, (mq->last_head + 3) % mask),
- CLIB_CACHE_LINE_BYTES, LOAD);
- CLIB_PREFETCH (&ring->desc[(mq->last_head + 4) % mask],
- CLIB_CACHE_LINE_BYTES, LOAD);
- CLIB_PREFETCH (&ring->desc[(mq->last_head + 5) % mask],
- CLIB_CACHE_LINE_BYTES, LOAD);
- }
+ CLIB_PREFETCH (memif_get_buffer
+ (mif, ring, (mq->last_head + 2) & mask),
+ CLIB_CACHE_LINE_BYTES, LOAD);
+ CLIB_PREFETCH (memif_get_buffer
+ (mif, ring, (mq->last_head + 3) & mask),
+ CLIB_CACHE_LINE_BYTES, LOAD);
+ CLIB_PREFETCH (&ring->desc[(mq->last_head + 4) & mask],
+ CLIB_CACHE_LINE_BYTES, LOAD);
+ CLIB_PREFETCH (&ring->desc[(mq->last_head + 5) & mask],
+ CLIB_CACHE_LINE_BYTES, LOAD);
vlib_buffer_t *first_b0 = 0;
u32 bi0 = 0, first_bi0 = 0;