dect
/
linux-2.6
Archived
13
0
Fork 0
Code Releases Activity

sch_red: fix red_calc_qavg_from_idle_time 

Since commit a4a710c4a7 (pkt_sched: Change PSCHED_SHIFT from 10 to
6) it seems RED/GRED are broken.

red_calc_qavg_from_idle_time() computes a delay in us units, but this
delay is now 16 times bigger than real delay, so the final qavg result
smaller than expected.

Use standard kernel time services since there is no need to obfuscate
them.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2011-11-30 12:10:53 +00:00 committed by David S. Miller
parent 917fbdb32f
commit ea6a5d3b97
1 changed files with 6 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
include/net/red.h
View File

@ -116,7 +116,7 @@ struct red_parms {
u32 qR; /* Cached random number */
unsigned long qavg; /* Average queue length: A scaled */
psched_time_t qidlestart; /* Start of current idle period */
ktime_t qidlestart; /* Start of current idle period */
};
static inline u32 red_rmask(u8 Plog)
@ -148,17 +148,17 @@ static inline void red_set_parms(struct red_parms *p,
static inline int red_is_idling(struct red_parms *p)
{
return p->qidlestart != PSCHED_PASTPERFECT;
return p->qidlestart.tv64 != 0;
}
static inline void red_start_of_idle_period(struct red_parms *p)
{
p->qidlestart = psched_get_time();
p->qidlestart = ktime_get();
}
static inline void red_end_of_idle_period(struct red_parms *p)
{
p->qidlestart = PSCHED_PASTPERFECT;
p->qidlestart.tv64 = 0;
}
static inline void red_restart(struct red_parms *p)
@ -170,13 +170,10 @@ static inline void red_restart(struct red_parms *p)
static inline unsigned long red_calc_qavg_from_idle_time(struct red_parms *p)
{
psched_time_t now;
long us_idle;
s64 delta = ktime_us_delta(ktime_get(), p->qidlestart);
long us_idle = min_t(s64, delta, p->Scell_max);
int shift;
now = psched_get_time();
us_idle = psched_tdiff_bounded(now, p->qidlestart, p->Scell_max);
/*
* The problem: ideally, average length queue recalcultion should
* be done over constant clock intervals. This is too expensive, so