forked from mirrors/linux
248f6571fd
netpoll tries to refill the skb queue on every packet send, independently if packets are being consumed from the pool or not. This was particularly problematic while being called from printk(), where the operation would be done while holding the console lock. Introduce a more intelligent approach to skb queue management. Instead of constantly attempting to refill the queue, the system now defers refilling to a work queue and only triggers the workqueue when a buffer is actually dequeued. This change significantly reduces operations with the lock held. Add a work_struct to the netpoll structure for asynchronous refilling, updating find_skb() to schedule refill work only when necessary (skb is dequeued). These changes have demonstrated a 15% reduction in time spent during netpoll_send_msg operations, especially when no SKBs are not consumed from consumed from pool. When SKBs are being dequeued, the improvement is even better, around 70%, mainly because refilling the SKB pool is now happening outside of the critical patch (with console_owner lock held). Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250304-netpoll_refill_v2-v1-1-06e2916a4642@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
115 lines
2.5 KiB
C
115 lines
2.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* Common code for low-level network console, dump, and debugger code
|
|
*
|
|
* Derived from netconsole, kgdb-over-ethernet, and netdump patches
|
|
*/
|
|
|
|
#ifndef _LINUX_NETPOLL_H
|
|
#define _LINUX_NETPOLL_H
|
|
|
|
#include <linux/netdevice.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/rcupdate.h>
|
|
#include <linux/list.h>
|
|
#include <linux/refcount.h>
|
|
|
|
union inet_addr {
|
|
__u32 all[4];
|
|
__be32 ip;
|
|
__be32 ip6[4];
|
|
struct in_addr in;
|
|
struct in6_addr in6;
|
|
};
|
|
|
|
struct netpoll {
|
|
struct net_device *dev;
|
|
netdevice_tracker dev_tracker;
|
|
char dev_name[IFNAMSIZ];
|
|
const char *name;
|
|
|
|
union inet_addr local_ip, remote_ip;
|
|
bool ipv6;
|
|
u16 local_port, remote_port;
|
|
u8 remote_mac[ETH_ALEN];
|
|
struct sk_buff_head skb_pool;
|
|
struct work_struct refill_wq;
|
|
};
|
|
|
|
struct netpoll_info {
|
|
refcount_t refcnt;
|
|
|
|
struct semaphore dev_lock;
|
|
|
|
struct sk_buff_head txq;
|
|
|
|
struct delayed_work tx_work;
|
|
|
|
struct netpoll *netpoll;
|
|
struct rcu_head rcu;
|
|
};
|
|
|
|
#ifdef CONFIG_NETPOLL
|
|
void netpoll_poll_dev(struct net_device *dev);
|
|
void netpoll_poll_disable(struct net_device *dev);
|
|
void netpoll_poll_enable(struct net_device *dev);
|
|
#else
|
|
static inline void netpoll_poll_disable(struct net_device *dev) { return; }
|
|
static inline void netpoll_poll_enable(struct net_device *dev) { return; }
|
|
#endif
|
|
|
|
int netpoll_send_udp(struct netpoll *np, const char *msg, int len);
|
|
void netpoll_print_options(struct netpoll *np);
|
|
int netpoll_parse_options(struct netpoll *np, char *opt);
|
|
int __netpoll_setup(struct netpoll *np, struct net_device *ndev);
|
|
int netpoll_setup(struct netpoll *np);
|
|
void __netpoll_cleanup(struct netpoll *np);
|
|
void __netpoll_free(struct netpoll *np);
|
|
void netpoll_cleanup(struct netpoll *np);
|
|
void do_netpoll_cleanup(struct netpoll *np);
|
|
netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb);
|
|
|
|
#ifdef CONFIG_NETPOLL
|
|
static inline void *netpoll_poll_lock(struct napi_struct *napi)
|
|
{
|
|
struct net_device *dev = napi->dev;
|
|
|
|
if (dev && rcu_access_pointer(dev->npinfo)) {
|
|
int owner = smp_processor_id();
|
|
|
|
while (cmpxchg(&napi->poll_owner, -1, owner) != -1)
|
|
cpu_relax();
|
|
|
|
return napi;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static inline void netpoll_poll_unlock(void *have)
|
|
{
|
|
struct napi_struct *napi = have;
|
|
|
|
if (napi)
|
|
smp_store_release(&napi->poll_owner, -1);
|
|
}
|
|
|
|
static inline bool netpoll_tx_running(struct net_device *dev)
|
|
{
|
|
return irqs_disabled();
|
|
}
|
|
|
|
#else
|
|
static inline void *netpoll_poll_lock(struct napi_struct *napi)
|
|
{
|
|
return NULL;
|
|
}
|
|
static inline void netpoll_poll_unlock(void *have)
|
|
{
|
|
}
|
|
static inline bool netpoll_tx_running(struct net_device *dev)
|
|
{
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
#endif
|