linux-stable/include/net/pie.h
Mohit P. Tahiliani b42a3d7c7c pie: improve comments and commenting style
Improve the comments along with the commenting style used to
describe the members of the structures and their initial values
in the init functions.

Signed-off-by: Mohit P. Tahiliani <tahiliani@nitk.edu.in>
Signed-off-by: Leslie Monis <lesliemonis@gmail.com>
Signed-off-by: Gautam Ramakrishnan <gautamramk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-23 11:38:31 +01:00

127 lines
3.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef __NET_SCHED_PIE_H
#define __NET_SCHED_PIE_H
#include <linux/ktime.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#include <net/inet_ecn.h>
#include <net/pkt_sched.h>
#define MAX_PROB U64_MAX
#define DTIME_INVALID U64_MAX
#define QUEUE_THRESHOLD 16384
#define DQCOUNT_INVALID -1
#define PIE_SCALE 8
/**
* struct pie_params - contains pie parameters
* @target: target delay in pschedtime
* @tudpate: interval at which drop probability is calculated
* @limit: total number of packets that can be in the queue
* @alpha: parameter to control drop probability
* @beta: parameter to control drop probability
* @ecn: is ECN marking of packets enabled
* @bytemode: is drop probability scaled based on pkt size
* @dq_rate_estimator: is Little's law used for qdelay calculation
*/
struct pie_params {
psched_time_t target;
u32 tupdate;
u32 limit;
u32 alpha;
u32 beta;
u8 ecn;
u8 bytemode;
u8 dq_rate_estimator;
};
/**
* struct pie_vars - contains pie variables
* @qdelay: current queue delay
* @qdelay_old: queue delay in previous qdelay calculation
* @burst_time: burst time allowance
* @dq_tstamp: timestamp at which dq rate was last calculated
* @prob: drop probability
* @accu_prob: accumulated drop probability
* @dq_count: number of bytes dequeued in a measurement cycle
* @avg_dq_rate: calculated average dq rate
* @qlen_old: queue length during previous qdelay calculation
* @accu_prob_overflows: number of times accu_prob overflows
*/
struct pie_vars {
psched_time_t qdelay;
psched_time_t qdelay_old;
psched_time_t burst_time;
psched_time_t dq_tstamp;
u64 prob;
u64 accu_prob;
u64 dq_count;
u32 avg_dq_rate;
u32 qlen_old;
u8 accu_prob_overflows;
};
/**
* struct pie_stats - contains pie stats
* @packets_in: total number of packets enqueued
* @dropped: packets dropped due to pie action
* @overlimit: packets dropped due to lack of space in queue
* @ecn_mark: packets marked with ECN
* @maxq: maximum queue size
*/
struct pie_stats {
u32 packets_in;
u32 dropped;
u32 overlimit;
u32 ecn_mark;
u32 maxq;
};
/**
* struct pie_skb_cb - contains private skb vars
* @enqueue_time: timestamp when the packet is enqueued
*/
struct pie_skb_cb {
psched_time_t enqueue_time;
};
static inline void pie_params_init(struct pie_params *params)
{
params->target = PSCHED_NS2TICKS(15 * NSEC_PER_MSEC); /* 15 ms */
params->tupdate = usecs_to_jiffies(15 * USEC_PER_MSEC); /* 15 ms */
params->limit = 1000;
params->alpha = 2;
params->beta = 20;
params->ecn = false;
params->bytemode = false;
params->dq_rate_estimator = false;
}
static inline void pie_vars_init(struct pie_vars *vars)
{
vars->burst_time = PSCHED_NS2TICKS(150 * NSEC_PER_MSEC); /* 150 ms */
vars->dq_tstamp = DTIME_INVALID;
vars->accu_prob = 0;
vars->dq_count = DQCOUNT_INVALID;
vars->avg_dq_rate = 0;
vars->accu_prob_overflows = 0;
}
static inline struct pie_skb_cb *get_pie_cb(const struct sk_buff *skb)
{
qdisc_cb_private_validate(skb, sizeof(struct pie_skb_cb));
return (struct pie_skb_cb *)qdisc_skb_cb(skb)->data;
}
static inline psched_time_t pie_get_enqueue_time(const struct sk_buff *skb)
{
return get_pie_cb(skb)->enqueue_time;
}
static inline void pie_set_enqueue_time(struct sk_buff *skb)
{
get_pie_cb(skb)->enqueue_time = psched_get_time();
}
#endif