net/mlx5e: Implement RX mapped page cache for page recycle
Instead of reallocating and mapping pages for RX data-path,
recycle already used pages in a per ring cache.
Performance tests:
The following results were measured on a freshly booted system,
giving optimal baseline performance, as high-order pages are yet to
be fragmented and depleted.
We ran pktgen single-stream benchmarks, with iptables-raw-drop:
Single stride, 64 bytes:
* 4,739,057 - baseline
* 4,749,550 - order0 no cache
* 4,786,899 - order0 with cache
1% gain
Larger packets, no page cross, 1024 bytes:
* 3,982,361 - baseline
* 3,845,682 - order0 no cache
* 4,127,852 - order0 with cache
3.7% gain
Larger packets, every 3rd packet crosses a page, 1500 bytes:
* 3,731,189 - baseline
* 3,579,414 - order0 no cache
* 3,931,708 - order0 with cache
5.4% gain
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index 401b2f7..7dd4763 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -287,6 +287,18 @@
u8 tired;
};
+/* a single cache unit is capable to serve one napi call (for non-striding rq)
+ * or a MPWQE (for striding rq).
+ */
+#define MLX5E_CACHE_UNIT (MLX5_MPWRQ_PAGES_PER_WQE > NAPI_POLL_WEIGHT ? \
+ MLX5_MPWRQ_PAGES_PER_WQE : NAPI_POLL_WEIGHT)
+#define MLX5E_CACHE_SIZE (2 * roundup_pow_of_two(MLX5E_CACHE_UNIT))
+struct mlx5e_page_cache {
+ u32 head;
+ u32 tail;
+ struct mlx5e_dma_info page_cache[MLX5E_CACHE_SIZE];
+};
+
struct mlx5e_rq {
/* data path */
struct mlx5_wq_ll wq;
@@ -301,6 +313,8 @@
struct mlx5e_tstamp *tstamp;
struct mlx5e_rq_stats stats;
struct mlx5e_cq cq;
+ struct mlx5e_page_cache page_cache;
+
mlx5e_fp_handle_rx_cqe handle_rx_cqe;
mlx5e_fp_alloc_wqe alloc_wqe;
mlx5e_fp_dealloc_wqe dealloc_wqe;
@@ -651,6 +665,8 @@
int mlx5e_poll_rx_cq(struct mlx5e_cq *cq, int budget);
void mlx5e_free_tx_descs(struct mlx5e_sq *sq);
+void mlx5e_page_release(struct mlx5e_rq *rq, struct mlx5e_dma_info *dma_info,
+ bool recycle);
void mlx5e_handle_rx_cqe(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe);
void mlx5e_handle_rx_cqe_mpwrq(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe);
bool mlx5e_post_rx_wqes(struct mlx5e_rq *rq);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 136554b..8595b50 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -141,6 +141,10 @@
s->rx_buff_alloc_err += rq_stats->buff_alloc_err;
s->rx_cqe_compress_blks += rq_stats->cqe_compress_blks;
s->rx_cqe_compress_pkts += rq_stats->cqe_compress_pkts;
+ s->rx_cache_reuse += rq_stats->cache_reuse;
+ s->rx_cache_full += rq_stats->cache_full;
+ s->rx_cache_empty += rq_stats->cache_empty;
+ s->rx_cache_busy += rq_stats->cache_busy;
for (j = 0; j < priv->params.num_tc; j++) {
sq_stats = &priv->channel[i]->sq[j].stats;
@@ -475,6 +479,9 @@
INIT_WORK(&rq->am.work, mlx5e_rx_am_work);
rq->am.mode = priv->params.rx_cq_period_mode;
+ rq->page_cache.head = 0;
+ rq->page_cache.tail = 0;
+
return 0;
err_rq_wq_destroy:
@@ -485,6 +492,8 @@
static void mlx5e_destroy_rq(struct mlx5e_rq *rq)
{
+ int i;
+
switch (rq->wq_type) {
case MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ:
mlx5e_rq_free_mpwqe_info(rq);
@@ -493,6 +502,12 @@
kfree(rq->skb);
}
+ for (i = rq->page_cache.head; i != rq->page_cache.tail;
+ i = (i + 1) & (MLX5E_CACHE_SIZE - 1)) {
+ struct mlx5e_dma_info *dma_info = &rq->page_cache.page_cache[i];
+
+ mlx5e_page_release(rq, dma_info, false);
+ }
mlx5_wq_destroy(&rq->wq_ctrl);
}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 0c34daa..dc86779 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -305,11 +305,55 @@
mlx5e_tx_notify_hw(sq, &wqe->ctrl, 0);
}
+static inline bool mlx5e_rx_cache_put(struct mlx5e_rq *rq,
+ struct mlx5e_dma_info *dma_info)
+{
+ struct mlx5e_page_cache *cache = &rq->page_cache;
+ u32 tail_next = (cache->tail + 1) & (MLX5E_CACHE_SIZE - 1);
+
+ if (tail_next == cache->head) {
+ rq->stats.cache_full++;
+ return false;
+ }
+
+ cache->page_cache[cache->tail] = *dma_info;
+ cache->tail = tail_next;
+ return true;
+}
+
+static inline bool mlx5e_rx_cache_get(struct mlx5e_rq *rq,
+ struct mlx5e_dma_info *dma_info)
+{
+ struct mlx5e_page_cache *cache = &rq->page_cache;
+
+ if (unlikely(cache->head == cache->tail)) {
+ rq->stats.cache_empty++;
+ return false;
+ }
+
+ if (page_ref_count(cache->page_cache[cache->head].page) != 1) {
+ rq->stats.cache_busy++;
+ return false;
+ }
+
+ *dma_info = cache->page_cache[cache->head];
+ cache->head = (cache->head + 1) & (MLX5E_CACHE_SIZE - 1);
+ rq->stats.cache_reuse++;
+
+ dma_sync_single_for_device(rq->pdev, dma_info->addr, PAGE_SIZE,
+ DMA_FROM_DEVICE);
+ return true;
+}
+
static inline int mlx5e_page_alloc_mapped(struct mlx5e_rq *rq,
struct mlx5e_dma_info *dma_info)
{
- struct page *page = dev_alloc_page();
+ struct page *page;
+ if (mlx5e_rx_cache_get(rq, dma_info))
+ return 0;
+
+ page = dev_alloc_page();
if (unlikely(!page))
return -ENOMEM;
@@ -324,9 +368,12 @@
return 0;
}
-static inline void mlx5e_page_release(struct mlx5e_rq *rq,
- struct mlx5e_dma_info *dma_info)
+void mlx5e_page_release(struct mlx5e_rq *rq, struct mlx5e_dma_info *dma_info,
+ bool recycle)
{
+ if (likely(recycle) && mlx5e_rx_cache_put(rq, dma_info))
+ return;
+
dma_unmap_page(rq->pdev, dma_info->addr, PAGE_SIZE, DMA_FROM_DEVICE);
put_page(dma_info->page);
}
@@ -362,7 +409,7 @@
struct mlx5e_dma_info *dma_info = &wi->umr.dma_info[i];
page_ref_sub(dma_info->page, pg_strides);
- mlx5e_page_release(rq, dma_info);
+ mlx5e_page_release(rq, dma_info, true);
}
return err;
@@ -377,7 +424,7 @@
struct mlx5e_dma_info *dma_info = &wi->umr.dma_info[i];
page_ref_sub(dma_info->page, pg_strides - wi->skbs_frags[i]);
- mlx5e_page_release(rq, dma_info);
+ mlx5e_page_release(rq, dma_info, true);
}
}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
index 1f56543..6af8d79 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
@@ -76,6 +76,10 @@
u64 rx_buff_alloc_err;
u64 rx_cqe_compress_blks;
u64 rx_cqe_compress_pkts;
+ u64 rx_cache_reuse;
+ u64 rx_cache_full;
+ u64 rx_cache_empty;
+ u64 rx_cache_busy;
/* Special handling counters */
u64 link_down_events_phy;
@@ -107,6 +111,10 @@
{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_buff_alloc_err) },
{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_cqe_compress_blks) },
{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_cqe_compress_pkts) },
+ { MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_cache_reuse) },
+ { MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_cache_full) },
+ { MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_cache_empty) },
+ { MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_cache_busy) },
{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, link_down_events_phy) },
};
@@ -275,6 +283,10 @@
u64 buff_alloc_err;
u64 cqe_compress_blks;
u64 cqe_compress_pkts;
+ u64 cache_reuse;
+ u64 cache_full;
+ u64 cache_empty;
+ u64 cache_busy;
};
static const struct counter_desc rq_stats_desc[] = {
@@ -290,6 +302,10 @@
{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, buff_alloc_err) },
{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, cqe_compress_blks) },
{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, cqe_compress_pkts) },
+ { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, cache_reuse) },
+ { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, cache_full) },
+ { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, cache_empty) },
+ { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, cache_busy) },
};
struct mlx5e_sq_stats {