linux-toradex.git/include/net/red.h, branch v2.6.19.2 Linux kernel for Apalis and Colibri modules [PKT_SCHED] RED: Fix overflow in calculation of queue average 2006-08-05T05:59:51+00:00 Ilpo Järvinen ilpo.jarvinen@helsinki.fi 2006-08-04T23:36:18+00:00 c4c0ce5c57ef0ca47a4428a14de6b5c8cdf8de8a 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> 
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>
Don't include linux/config.h from anywhere else in include/ 2006-04-26T11:56:16+00:00 David Woodhouse dwmw2@infradead.org 2006-04-26T11:56:16+00:00 62c4f0a2d5a188f73a94f2cb8ea0dba3e7cf0a7f Signed-off-by: David Woodhouse <dwmw2@infradead.org> 
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[PKT_SCHED]: Generic RED layer 2005-11-05T21:02:24+00:00 Thomas Graf tgraf@suug.ch 2005-11-05T20:14:03+00:00 a783474591f2eed0348e08b15934fa9a25e23b3e 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> 
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>