[PATCH net-next 1/2] net: mana: Use per-queue allocation for tx_qp to reduce allocation size

Aditya Garg
2026-04-14T15:15:17Z

Convert tx_qp from a single contiguous array allocation to per-queue
individual allocations. Each mana_tx_qp struct is approximately 35KB.
With many queues (e.g., 32/64), the flat array requires a single
contiguous allocation that can fail under memory fragmentation.

Change mana_tx_qp *tx_qp to mana_tx_qp **tx_qp (array of pointers),
allocating each queue's mana_tx_qp individually via kvzalloc. This
reduces each allocation to ~35KB and provides vmalloc fallback,
avoiding allocation failure due to fragmentation.

Signed-off-by: Aditya Garg <gargaditya@linux.microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
.../net/ethernet/microsoft/mana/mana_bpf.c | 2 +-
drivers/net/ethernet/microsoft/mana/mana_en.c | 49 ++++++++++++-------
.../ethernet/microsoft/mana/mana_ethtool.c | 2 +-
include/net/mana/mana.h | 2 +-
4 files changed, 33 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_bpf.c b/drivers/net/ethernet/microsoft/mana/mana_bpf.c
index 7697c9b52ed3..b5e9bb184a1d 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_bpf.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_bpf.c
@@ -68,7 +68,7 @@ int mana_xdp_xmit(struct net_device *ndev, int n, struct xdp_frame **frames,
count++;
}

- tx_stats = &apc->tx_qp[q_idx].txq.stats;
+ tx_stats = &apc->tx_qp[q_idx]->txq.stats;

u64_stats_update_begin(&tx_stats->syncp);
tx_stats->xdp_xmit += count;
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 09a53c977545..49ee77b0939a 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -355,9 +355,9 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
if (skb_cow_head(skb, MANA_HEADROOM))
goto tx_drop_count;

- txq = &apc->tx_qp[txq_idx].txq;
+ txq = &apc->tx_qp[txq_idx]->txq;
gdma_sq = txq->gdma_sq;
- cq = &apc->tx_qp[txq_idx].tx_cq;
+ cq = &apc->tx_qp[txq_idx]->tx_cq;
tx_stats = &txq->stats;

BUILD_BUG_ON(MAX_TX_WQE_SGL_ENTRIES != MANA_MAX_TX_WQE_SGL_ENTRIES);
@@ -614,7 +614,7 @@ static void mana_get_stats64(struct net_device *ndev,
}

for (q = 0; q < num_queues; q++) {
- tx_stats = &apc->tx_qp[q].txq.stats;
+ tx_stats = &apc->tx_qp[q]->txq.stats;

do {
start = u64_stats_fetch_begin(&tx_stats->syncp);
@@ -2284,21 +2284,26 @@ static void mana_destroy_txq(struct mana_port_context *apc)
return;

for (i = 0; i < apc->num_queues; i++) {
- debugfs_remove_recursive(apc->tx_qp[i].mana_tx_debugfs);
- apc->tx_qp[i].mana_tx_debugfs = NULL;
+ if (!apc->tx_qp[i])
+ continue;
+
+ debugfs_remove_recursive(apc->tx_qp[i]->mana_tx_debugfs);
+ apc->tx_qp[i]->mana_tx_debugfs = NULL;

- napi = &apc->tx_qp[i].tx_cq.napi;
- if (apc->tx_qp[i].txq.napi_initialized) {
+ napi = &apc->tx_qp[i]->tx_cq.napi;
+ if (apc->tx_qp[i]->txq.napi_initialized) {
napi_synchronize(napi);
napi_disable_locked(napi);
netif_napi_del_locked(napi);
- apc->tx_qp[i].txq.napi_initialized = false;
+ apc->tx_qp[i]->txq.napi_initialized = false;
}
- mana_destroy_wq_obj(apc, GDMA_SQ, apc->tx_qp[i].tx_object);
+ mana_destroy_wq_obj(apc, GDMA_SQ, apc->tx_qp[i]->tx_object);

- mana_deinit_cq(apc, &apc->tx_qp[i].tx_cq);
+ mana_deinit_cq(apc, &apc->tx_qp[i]->tx_cq);

- mana_deinit_txq(apc, &apc->tx_qp[i].txq);
+ mana_deinit_txq(apc, &apc->tx_qp[i]->txq);
+
+ kvfree(apc->tx_qp[i]);
}

kfree(apc->tx_qp);
@@ -2307,7 +2312,7 @@ static void mana_destroy_txq(struct mana_port_context *apc)

static void mana_create_txq_debugfs(struct mana_port_context *apc, int idx)
{
- struct mana_tx_qp *tx_qp = &apc->tx_qp[idx];
+ struct mana_tx_qp *tx_qp = apc->tx_qp[idx];
char qnum[32];

sprintf(qnum, "TX-%d", idx);
@@ -2346,7 +2351,7 @@ static int mana_create_txq(struct mana_port_context *apc,
int err;
int i;

- apc->tx_qp = kzalloc_objs(struct mana_tx_qp, apc->num_queues);
+ apc->tx_qp = kzalloc_objs(struct mana_tx_qp *, apc->num_queues);
if (!apc->tx_qp)
return -ENOMEM;

@@ -2366,10 +2371,16 @@ static int mana_create_txq(struct mana_port_context *apc,
gc = gd->gdma_context;

for (i = 0; i < apc->num_queues; i++) {
- apc->tx_qp[i].tx_object = INVALID_MANA_HANDLE;
+ apc->tx_qp[i] = kvzalloc_obj(*apc->tx_qp[i]);
+ if (!apc->tx_qp[i]) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ apc->tx_qp[i]->tx_object = INVALID_MANA_HANDLE;

/* Create SQ */
- txq = &apc->tx_qp[i].txq;
+ txq = &apc->tx_qp[i]->txq;

u64_stats_init(&txq->stats.syncp);
txq->ndev = net;
@@ -2387,7 +2398,7 @@ static int mana_create_txq(struct mana_port_context *apc,
goto out;

/* Create SQ's CQ */
- cq = &apc->tx_qp[i].tx_cq;
+ cq = &apc->tx_qp[i]->tx_cq;
cq->type = MANA_CQ_TYPE_TX;

cq->txq = txq;
@@ -2416,7 +2427,7 @@ static int mana_create_txq(struct mana_port_context *apc,

err = mana_create_wq_obj(apc, apc->port_handle, GDMA_SQ,
&wq_spec, &cq_spec,
- &apc->tx_qp[i].tx_object);
+ &apc->tx_qp[i]->tx_object);

if (err)
goto out;
@@ -3242,7 +3253,7 @@ static int mana_dealloc_queues(struct net_device *ndev)
*/

for (i = 0; i < apc->num_queues; i++) {
- txq = &apc->tx_qp[i].txq;
+ txq = &apc->tx_qp[i]->txq;
tsleep = 1000;
while (atomic_read(&txq->pending_sends) > 0 &&
time_before(jiffies, timeout)) {
@@ -3261,7 +3272,7 @@ static int mana_dealloc_queues(struct net_device *ndev)
}

for (i = 0; i < apc->num_queues; i++) {
- txq = &apc->tx_qp[i].txq;
+ txq = &apc->tx_qp[i]->txq;
while ((skb = skb_dequeue(&txq->pending_skbs))) {
mana_unmap_skb(skb, apc);
dev_kfree_skb_any(skb);
diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
index f2d220b371b5..f5901e4c9816 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
@@ -251,7 +251,7 @@ static void mana_get_ethtool_stats(struct net_device *ndev,
}

for (q = 0; q < num_queues; q++) {
- tx_stats = &apc->tx_qp[q].txq.stats;
+ tx_stats = &apc->tx_qp[q]->txq.stats;

do {
start = u64_stats_fetch_begin(&tx_stats->syncp);
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index a078af283bdd..60b4a4146ea2 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -505,7 +505,7 @@ struct mana_port_context {
bool tx_shortform_allowed;
u16 tx_vp_offset;

- struct mana_tx_qp *tx_qp;
+ struct mana_tx_qp **tx_qp;

/* Indirection Table for RX & TX. The values are queue indexes */
u32 *indir_table;
--
2.43.0