include/net/pkt_sched.h

Source file repositories/reference/linux-study-clean/include/net/pkt_sched.h

File Facts

System
Linux kernel
Corpus path
include/net/pkt_sched.h
Extension
.h
Size
8523 bytes
Lines
336
Domain
Networking Core
Bucket
Sockets, Protocols, Packet Path, And Network Policy
Inferred role
Networking Core: implementation source
Status
source implementation candidate

Why This File Exists

Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.

Dependency Surface

Detected Declarations

Annotated Snippet

struct qdisc_walker {
	int	stop;
	int	skip;
	int	count;
	int	(*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
};

#define qdisc_priv(q)							\
	_Generic(q,							\
		 const struct Qdisc * : (const void *)&q->privdata,	\
		 struct Qdisc * : (void *)&q->privdata)

/* 
   Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
   
   Normal IP packet size ~ 512byte, hence:

   0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
   10Mbit ethernet.

   10msec resolution -> <50Kbit/sec.
   
   The result: [34]86 is not good choice for QoS router :-(

   The things are not so bad, because we may use artificial
   clock evaluated by integration of network data flow
   in the most critical places.
 */

typedef u64	psched_time_t;

/* Avoid doing 64 bit divide */
#define PSCHED_SHIFT			6
#define PSCHED_TICKS2NS(x)		((s64)(x) << PSCHED_SHIFT)
#define PSCHED_NS2TICKS(x)		((x) >> PSCHED_SHIFT)

#define PSCHED_TICKS_PER_SEC		PSCHED_NS2TICKS(NSEC_PER_SEC)
#define PSCHED_PASTPERFECT		0

static inline psched_time_t psched_get_time(void)
{
	return PSCHED_NS2TICKS(ktime_get_ns());
}

struct qdisc_watchdog {
	struct hrtimer	timer;
	struct Qdisc	*qdisc;
};

void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
				 clockid_t clockid);
void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);

void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires,
				      u64 delta_ns);

static inline void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd,
					      u64 expires)
{
	return qdisc_watchdog_schedule_range_ns(wd, expires, 0ULL);
}

static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
					   psched_time_t expires)
{
	qdisc_watchdog_schedule_ns(wd, PSCHED_TICKS2NS(expires));
}

void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);

extern struct Qdisc_ops pfifo_qdisc_ops;
extern struct Qdisc_ops bfifo_qdisc_ops;
extern struct Qdisc_ops pfifo_head_drop_qdisc_ops;

int fifo_set_limit(struct Qdisc *q, unsigned int limit);
struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
			       unsigned int limit,
			       struct netlink_ext_ack *extack);

int register_qdisc(struct Qdisc_ops *qops);
void unregister_qdisc(struct Qdisc_ops *qops);
#define NET_SCH_ALIAS_PREFIX "net-sch-"
#define MODULE_ALIAS_NET_SCH(id)	MODULE_ALIAS(NET_SCH_ALIAS_PREFIX id)
void qdisc_get_default(char *id, size_t len);
int qdisc_set_default(const char *id);

void qdisc_hash_add(struct Qdisc *q, bool invisible);
void qdisc_hash_del(struct Qdisc *q);
struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle);

Annotation

Implementation Notes