[PATCH net-next v5 13/15] ibmveth: Expose per-queue buffer pool details via debugfs
From: Mingming Cao <hidden>
Date: 2026-08-14 07:38:43
Also in:
netdev
Subsystem:
ibm power virtual ethernet device driver, linux for powerpc (32-bit and 64-bit), networking drivers, the rest · Maintainers:
Nick Child, Madhavan Srinivasan, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Add a read-only buffer_pools debugfs file that lists size, buff_size,
active, and available for every RX queue and buffer pool. That is the
MQ diagnostic view (multi-line table), which does not belong in sysfs.
Keep the historical queue-0 poolN sysfs ABI unchanged:
.../poolN/{active,num,size}
Those are one-value-per-file *configuration* knobs for buffer-pool
classes on queue 0, not one directory per RX queue. With MQ, queue 0
pool geometry remains the shared template: open copies it to queues
1..N. Per-queue runtime pressure is what debugfs shows; this series
does not add per-queue pool sysfs dirs.
Unlike ibmvnic (one RX pool per RX queue, sized from firmware, almost
no pool sysfs), ibmveth historically has multiple size-class pools and
already exported poolN via sysfs. Moving only the new all-queue dump
to debugfs matches sysfs "one value per file" review feedback without
breaking that config ABI.
Path: /sys/kernel/debug/ibmveth/<dev_name>/buffer_pools
(e.g. /sys/kernel/debug/ibmveth/30000002/buffer_pools)
Signed-off-by: Mingming Cao <redacted>
Reviewed-by: Dave Marquardt <redacted>
Tested-by: Shaik Abdulla <redacted>
---
Changes in v5:
- debugfs buffer_pools_show walks get_num_rx_queues()
- Series renumber: mailed v4 11/14 debugfs -> tip P13 (14->15)
- Path uses stable vio dev_name under a driver-owned root (not netdev
name - avoids rename/collide)
- rtnl_lock around dump (writers are under RTNL)
- Show Active/Available as 0 when pool !live (debugfs view; free-path
available clear already in the buffer-submit patch)
Changes in v4:
- Move the all-queue buffer_pools diagnostic from sysfs to debugfs;
subject updated to match.
- Keep historical queue-0 poolN/{active,num,size} sysfs as one-value
config (template for MQ); do not add per-queue pool sysfs dirs.
drivers/net/ethernet/ibm/ibmveth.c | 69 ++++++++++++++++++++++++++++++
drivers/net/ethernet/ibm/ibmveth.h | 2 +
2 files changed, 71 insertions(+)
diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index 5d4ca4b3d3d0..1b58a3c6ce77 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c@@ -31,6 +31,7 @@ #include <linux/ipv6.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/debugfs.h> #include <asm/hvcall.h> #include <linux/atomic.h> #include <asm/vio.h>
@@ -3421,6 +3422,68 @@ static const struct net_device_ops ibmveth_netdev_ops = { #endif }; +static int ibmveth_buffer_pools_show(struct seq_file *m, void *v) +{ + struct ibmveth_adapter *adapter = m->private; + int i, j; + + /* + * Writers (veth_pool_store, open template copy, reset close/open) + * update these fields under RTNL. Take the same lock so the dump + * is not a torn scalar snapshot. Not required for + * memory safety â embedded arrays only. + */ + rtnl_lock(); + + seq_puts(m, "Queue Pool Size BuffSize Active Available\n"); + seq_puts(m, "----- ---- ---- -------- ------ ---------\n"); + if (!adapter->opened) + seq_puts(m, "# down: Active/Available 0 unless allocated\n"); + + for (i = 0; i < ibmveth_get_num_rx_queues(adapter); i++) { + for (j = 0; j < IBMVETH_NUM_BUFF_POOLS; j++) { + struct ibmveth_buff_pool *pool = + &adapter->rx_buff_pool[i][j]; + bool live = pool->skbuff && pool->free_map; + int active = live ? pool->active : 0; + int available = live ? atomic_read(&pool->available) + : 0; + + seq_printf(m, "%5d %4d %4u %8u %6d %9d\n", + i, j, pool->size, pool->buff_size, + active, available); + } + } + + rtnl_unlock(); + return 0; +} +DEFINE_SHOW_ATTRIBUTE(ibmveth_buffer_pools); + +/* Driver-owned root so per-adapter dirs use a stable vio name, not the + * mutable netdev->name (avoids stale names / eth0 collisions after rename). + */ +static struct dentry *ibmveth_dbg_root; + +static void ibmveth_debugfs_init(struct ibmveth_adapter *adapter) +{ + if (!ibmveth_dbg_root) + ibmveth_dbg_root = + debugfs_create_dir(ibmveth_driver_name, NULL); + + adapter->debugfs_dir = + debugfs_create_dir(dev_name(&adapter->vdev->dev), + ibmveth_dbg_root); + debugfs_create_file("buffer_pools", 0400, adapter->debugfs_dir, + adapter, &ibmveth_buffer_pools_fops); +} + +static void ibmveth_debugfs_exit(struct ibmveth_adapter *adapter) +{ + debugfs_remove_recursive(adapter->debugfs_dir); + adapter->debugfs_dir = NULL; +} + static void ibmveth_put_pool_kobjs(struct ibmveth_adapter *adapter, int pools_ready) {
@@ -3647,6 +3710,8 @@ static int ibmveth_probe(struct vio_dev *dev, const struct vio_device_id *id) netdev_dbg(netdev, "registered\n"); + ibmveth_debugfs_init(adapter); + return 0; }
@@ -3656,6 +3721,8 @@ static void ibmveth_remove(struct vio_dev *dev) struct ibmveth_adapter *adapter = netdev_priv(netdev); int i; + ibmveth_debugfs_exit(adapter); + for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) kobject_put(&adapter->rx_buff_pool[0][i].kobj);
@@ -3891,6 +3958,8 @@ static int __init ibmveth_module_init(void) static void __exit ibmveth_module_exit(void) { vio_unregister_driver(&ibmveth_driver); + debugfs_remove_recursive(ibmveth_dbg_root); + ibmveth_dbg_root = NULL; } module_init(ibmveth_module_init);
diff --git a/drivers/net/ethernet/ibm/ibmveth.h b/drivers/net/ethernet/ibm/ibmveth.h
index 0960448f53ea..8c826d23ddf4 100644
--- a/drivers/net/ethernet/ibm/ibmveth.h
+++ b/drivers/net/ethernet/ibm/ibmveth.h@@ -392,6 +392,8 @@ struct ibmveth_adapter { struct ibmveth_rx_queue_stats *rx_qstats; struct ibmveth_tx_queue_stats *tx_qstats; + struct dentry *debugfs_dir; + /* Ethtool settings */ u8 duplex; u32 speed;
--
2.50.1 (Apple Git-155)