xen-netback: Adding debugfs "io_ring_qX" files

This patch adds debugfs capabilities to netback. There used to be a similar
patch floating around for classic kernel, but it used procfs. It is based on a
very similar blkback patch.
It creates xen-netback/[vifname]/io_ring_q[queueno] files, reading them output
various ring variables etc. Writing "kick" into it imitates an interrupt
happened, it can be useful to check whether the ring is just stalled due to a
missed interrupt.

Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Zoltan Kiss 2014-07-08 19:49:14 +01:00 коммит произвёл David S. Miller
Родитель a37934fc0d
Коммит f51de24356
4 изменённых файлов: 200 добавлений и 2 удалений

Просмотреть файл

@ -44,6 +44,7 @@
#include <xen/interface/grant_table.h>
#include <xen/grant_table.h>
#include <xen/xenbus.h>
#include <linux/debugfs.h>
typedef unsigned int pending_ring_idx_t;
#define INVALID_PENDING_RING_IDX (~0U)
@ -224,6 +225,10 @@ struct xenvif {
struct xenvif_queue *queues;
unsigned int num_queues; /* active queues, resource allocated */
#ifdef CONFIG_DEBUG_FS
struct dentry *xenvif_dbg_root;
#endif
/* Miscellaneous private stuff. */
struct net_device *dev;
};
@ -297,10 +302,16 @@ static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue)
/* Callback from stack when TX packet can be released */
void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
irqreturn_t xenvif_interrupt(int irq, void *dev_id);
extern bool separate_tx_rx_irq;
extern unsigned int rx_drain_timeout_msecs;
extern unsigned int rx_drain_timeout_jiffies;
extern unsigned int xenvif_max_queues;
#ifdef CONFIG_DEBUG_FS
extern struct dentry *xen_netback_dbg_root;
#endif
#endif /* __XEN_NETBACK__COMMON_H__ */

Просмотреть файл

@ -102,7 +102,7 @@ static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}
static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
irqreturn_t xenvif_interrupt(int irq, void *dev_id)
{
xenvif_tx_interrupt(irq, dev_id);
xenvif_rx_interrupt(irq, dev_id);

Просмотреть файл

@ -1987,6 +1987,13 @@ static int __init netback_init(void)
rx_drain_timeout_jiffies = msecs_to_jiffies(rx_drain_timeout_msecs);
#ifdef CONFIG_DEBUG_FS
xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL);
if (IS_ERR_OR_NULL(xen_netback_dbg_root))
pr_warn("Init of debugfs returned %ld!\n",
PTR_ERR(xen_netback_dbg_root));
#endif /* CONFIG_DEBUG_FS */
return 0;
failed_init:
@ -1997,6 +2004,10 @@ module_init(netback_init);
static void __exit netback_fini(void)
{
#ifdef CONFIG_DEBUG_FS
if (!IS_ERR_OR_NULL(xen_netback_dbg_root))
debugfs_remove_recursive(xen_netback_dbg_root);
#endif /* CONFIG_DEBUG_FS */
xenvif_xenbus_fini();
}
module_exit(netback_fini);

Просмотреть файл

@ -44,6 +44,175 @@ static void unregister_hotplug_status_watch(struct backend_info *be);
static void set_backend_state(struct backend_info *be,
enum xenbus_state state);
#ifdef CONFIG_DEBUG_FS
struct dentry *xen_netback_dbg_root = NULL;
static int xenvif_read_io_ring(struct seq_file *m, void *v)
{
struct xenvif_queue *queue = m->private;
struct xen_netif_tx_back_ring *tx_ring = &queue->tx;
struct xen_netif_rx_back_ring *rx_ring = &queue->rx;
if (tx_ring->sring) {
struct xen_netif_tx_sring *sring = tx_ring->sring;
seq_printf(m, "Queue %d\nTX: nr_ents %u\n", queue->id,
tx_ring->nr_ents);
seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
sring->req_prod,
sring->req_prod - sring->rsp_prod,
tx_ring->req_cons,
tx_ring->req_cons - sring->rsp_prod,
sring->req_event,
sring->req_event - sring->rsp_prod);
seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n",
sring->rsp_prod,
tx_ring->rsp_prod_pvt,
tx_ring->rsp_prod_pvt - sring->rsp_prod,
sring->rsp_event,
sring->rsp_event - sring->rsp_prod);
seq_printf(m, "pending prod %u pending cons %u nr_pending_reqs %u\n",
queue->pending_prod,
queue->pending_cons,
nr_pending_reqs(queue));
seq_printf(m, "dealloc prod %u dealloc cons %u dealloc_queue %u\n\n",
queue->dealloc_prod,
queue->dealloc_cons,
queue->dealloc_prod - queue->dealloc_cons);
}
if (rx_ring->sring) {
struct xen_netif_rx_sring *sring = rx_ring->sring;
seq_printf(m, "RX: nr_ents %u\n", rx_ring->nr_ents);
seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
sring->req_prod,
sring->req_prod - sring->rsp_prod,
rx_ring->req_cons,
rx_ring->req_cons - sring->rsp_prod,
sring->req_event,
sring->req_event - sring->rsp_prod);
seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n\n",
sring->rsp_prod,
rx_ring->rsp_prod_pvt,
rx_ring->rsp_prod_pvt - sring->rsp_prod,
sring->rsp_event,
sring->rsp_event - sring->rsp_prod);
}
seq_printf(m, "NAPI state: %lx NAPI weight: %d TX queue len %u\n"
"Credit timer_pending: %d, credit: %lu, usec: %lu\n"
"remaining: %lu, expires: %lu, now: %lu\n",
queue->napi.state, queue->napi.weight,
skb_queue_len(&queue->tx_queue),
timer_pending(&queue->credit_timeout),
queue->credit_bytes,
queue->credit_usec,
queue->remaining_credit,
queue->credit_timeout.expires,
jiffies);
return 0;
}
#define XENVIF_KICK_STR "kick"
static ssize_t
xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count,
loff_t *ppos)
{
struct xenvif_queue *queue =
((struct seq_file *)filp->private_data)->private;
int len;
char write[sizeof(XENVIF_KICK_STR)];
/* don't allow partial writes and check the length */
if (*ppos != 0)
return 0;
if (count < sizeof(XENVIF_KICK_STR) - 1)
return -ENOSPC;
len = simple_write_to_buffer(write,
sizeof(write),
ppos,
buf,
count);
if (len < 0)
return len;
if (!strncmp(write, XENVIF_KICK_STR, sizeof(XENVIF_KICK_STR) - 1))
xenvif_interrupt(0, (void *)queue);
else {
pr_warn("Unknown command to io_ring_q%d. Available: kick\n",
queue->id);
count = -EINVAL;
}
return count;
}
static int xenvif_dump_open(struct inode *inode, struct file *filp)
{
int ret;
void *queue = NULL;
if (inode->i_private)
queue = inode->i_private;
ret = single_open(filp, xenvif_read_io_ring, queue);
filp->f_mode |= FMODE_PWRITE;
return ret;
}
static const struct file_operations xenvif_dbg_io_ring_ops_fops = {
.owner = THIS_MODULE,
.open = xenvif_dump_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.write = xenvif_write_io_ring,
};
static void xenvif_debugfs_addif(struct xenvif_queue *queue)
{
struct dentry *pfile;
struct xenvif *vif = queue->vif;
int i;
if (IS_ERR_OR_NULL(xen_netback_dbg_root))
return;
vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
xen_netback_dbg_root);
if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) {
for (i = 0; i < vif->num_queues; ++i) {
char filename[sizeof("io_ring_q") + 4];
snprintf(filename, sizeof(filename), "io_ring_q%d", i);
pfile = debugfs_create_file(filename,
S_IRUSR | S_IWUSR,
vif->xenvif_dbg_root,
&vif->queues[i],
&xenvif_dbg_io_ring_ops_fops);
if (IS_ERR_OR_NULL(pfile))
pr_warn("Creation of io_ring file returned %ld!\n",
PTR_ERR(pfile));
}
} else
netdev_warn(vif->dev,
"Creation of vif debugfs dir returned %ld!\n",
PTR_ERR(vif->xenvif_dbg_root));
}
static void xenvif_debugfs_delif(struct xenvif *vif)
{
if (IS_ERR_OR_NULL(xen_netback_dbg_root))
return;
if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root))
debugfs_remove_recursive(vif->xenvif_dbg_root);
vif->xenvif_dbg_root = NULL;
}
#endif /* CONFIG_DEBUG_FS */
static int netback_remove(struct xenbus_device *dev)
{
struct backend_info *be = dev_get_drvdata(&dev->dev);
@ -246,8 +415,12 @@ static void backend_create_xenvif(struct backend_info *be)
static void backend_disconnect(struct backend_info *be)
{
if (be->vif)
if (be->vif) {
#ifdef CONFIG_DEBUG_FS
xenvif_debugfs_delif(be->vif);
#endif /* CONFIG_DEBUG_FS */
xenvif_disconnect(be->vif);
}
}
static void backend_connect(struct backend_info *be)
@ -560,6 +733,9 @@ static void connect(struct backend_info *be)
be->vif->num_queues = queue_index;
goto err;
}
#ifdef CONFIG_DEBUG_FS
xenvif_debugfs_addif(queue);
#endif /* CONFIG_DEBUG_FS */
}
/* Initialisation completed, tell core driver the number of