nagai/kernel
3
0
Fork 0
forked from mirrors/linux
Code Pull requests Activity

pie: improve comments and commenting style

Browse source 
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>
This commit is contained in:
Mohit P. Tahiliani 2020-01-22 23:52:29 +05:30 committed by David S. Miller
parent 2dfb1952a9
commit b42a3d7c7c
1 changed files with 58 additions and 27 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

85
include/net/pie.h
View file

@ -14,42 +14,74 @@
#define DQCOUNT_INVALID -1 #define DQCOUNT_INVALID -1
#define PIE_SCALE 8 #define PIE_SCALE 8
/* parameters used */ /**
* 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 { struct pie_params {
psched_time_t target; /* user specified target delay in pschedtime */ psched_time_t target;
u32 tupdate; /* timer frequency (in jiffies) */ u32 tupdate;
u32 limit; /* number of packets that can be enqueued */ u32 limit;
u32 alpha; /* alpha and beta are between 0 and 32 */ u32 alpha;
u32 beta; /* and are used for shift relative to 1 */ u32 beta;
u8 ecn; /* true if ecn is enabled */ u8 ecn;
u8 bytemode; /* to scale drop early prob based on pkt size */ u8 bytemode;
u8 dq_rate_estimator; /* to calculate delay using Little's law */ u8 dq_rate_estimator;
}; };
/* variables used */ /**
* 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 { struct pie_vars {
psched_time_t qdelay; psched_time_t qdelay;
psched_time_t qdelay_old; psched_time_t qdelay_old;
psched_time_t burst_time; psched_time_t burst_time;
psched_time_t dq_tstamp; /* drain rate */ psched_time_t dq_tstamp;
u64 prob; /* probability but scaled by u64 limit. */ u64 prob;
u64 accu_prob; /* accumulated drop probability */ u64 accu_prob;
u64 dq_count; /* measured in bytes */ u64 dq_count;
u32 avg_dq_rate; /* bytes per pschedtime tick,scaled */ u32 avg_dq_rate;
u32 qlen_old; /* in bytes */ u32 qlen_old;
u8 accu_prob_overflows; /* overflows of accu_prob */ u8 accu_prob_overflows;
}; };
/* statistics gathering */ /**
* 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 { struct pie_stats {
u32 packets_in; /* total number of packets enqueued */ u32 packets_in;
u32 dropped; /* packets dropped due to pie_action */ u32 dropped;
u32 overlimit; /* dropped due to lack of space in queue */ u32 overlimit;
u32 ecn_mark; /* packets marked with ECN */ u32 ecn_mark;
u32 maxq; /* maximum queue size */ u32 maxq;
}; };
/* private skb vars */ /**
* struct pie_skb_cb - contains private skb vars
* @enqueue_time: timestamp when the packet is enqueued
*/
struct pie_skb_cb { struct pie_skb_cb {
psched_time_t enqueue_time; psched_time_t enqueue_time;
}; };
@ -58,7 +90,7 @@ static inline void pie_params_init(struct pie_params *params)
{ {
params->target = PSCHED_NS2TICKS(15 * NSEC_PER_MSEC); /* 15 ms */ params->target = PSCHED_NS2TICKS(15 * NSEC_PER_MSEC); /* 15 ms */
params->tupdate = usecs_to_jiffies(15 * USEC_PER_MSEC); /* 15 ms */ params->tupdate = usecs_to_jiffies(15 * USEC_PER_MSEC); /* 15 ms */
params->limit = 1000; /* default of 1000 packets */ params->limit = 1000;
params->alpha = 2; params->alpha = 2;
params->beta = 20; params->beta = 20;
params->ecn = false; params->ecn = false;
@ -68,8 +100,7 @@ static inline void pie_params_init(struct pie_params *params)
static inline void pie_vars_init(struct pie_vars *vars) static inline void pie_vars_init(struct pie_vars *vars)
{ {
/* default of 150 ms in pschedtime */ vars->burst_time = PSCHED_NS2TICKS(150 * NSEC_PER_MSEC); /* 150 ms */
vars->burst_time = PSCHED_NS2TICKS(150 * NSEC_PER_MSEC);
vars->dq_tstamp = DTIME_INVALID; vars->dq_tstamp = DTIME_INVALID;
vars->accu_prob = 0; vars->accu_prob = 0;
vars->dq_count = DQCOUNT_INVALID; vars->dq_count = DQCOUNT_INVALID;