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>
The RED statistics structure includes backlog field which is not
set or used by any code.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This cleanup patch puts struct/union/enum opening braces,
in first line to ease grep games.
struct something
{
becomes :
struct something {
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Overflow can occur very easily with 32 bits, e.g., with 1 second
us_idle is approx. 2^20, which leaves only 11-Wlog bits for queue
length. Since the EWMA exponent is typically around 9, queue
lengths larger than 2^2 cause overflow. Whether the affected
branch is taken when us_idle is as high as 1 second, depends on
Scell_log, but with rather reasonable configuration Scell_log is
large enough to cause p->Stab to have zero index, which always
results zero shift (typically also few other small indices result
in zero shift).
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Extracts the RED algorithm from sch_red.c and puts it into include/net/red.h
for use by other RED based modules. The statistics are extended to be more
fine grained in order to differ between probability/forced marks/drops.
We now reset the average queue length when setting new parameters, leaving
it might result in an unreasonable qavg for a while depending on the value of W.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Eric Dumazet
stephen hemminger
Patrick McHardy
Ilpo Järvinen
David Woodhouse
Thomas Graf