The optional mask which may be added to int values is considered by the
kernel only if it is non-zero, therefore tc should only then also print
it.
Without this, not passing a mask value like so:
| # tc filter add dev d0 parent 8001: \
| basic match meta\(vlan eq 1\) \
| classid 8001:1
Would lead to tc printing an all-zero mask later:
| # tc filter show dev d0
| filter parent 8001: protocol all pref 49151 basic
| filter parent 8001: protocol all pref 49151 basic handle 0x1 flowid 8001:1
| meta(vlan mask 0x00000000 eq 1)
This is obviously confusing as an all-zero mask strictly means to
eliminate all bits from the value, but the opposite is the case.
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Kernel code and interface.
--------------------------
* Compile time switches
There is only one, but very important, compile time switch.
It is not settable by "make config", but should be selected
manually and after a bit of thinking in <include/net/pkt_sched.h>
PSCHED_CLOCK_SOURCE can take three values:
PSCHED_GETTIMEOFDAY
PSCHED_JIFFIES
PSCHED_CPU
PSCHED_GETTIMEOFDAY
Default setting is the most conservative PSCHED_GETTIMEOFDAY.
It is very slow both because of weird slowness of do_gettimeofday()
and because it forces code to use unnatural "timeval" format,
where microseconds and seconds fields are separate.
Besides that, it will misbehave, when delays exceed 2 seconds
(f.e. very slow links or classes bounded to small slice of bandwidth)
To resume: as only you will get it working, select correct clock
source and forget about PSCHED_GETTIMEOFDAY forever.
PSCHED_JIFFIES
Clock is derived from jiffies. On architectures with HZ=100
granularity of this clock is not enough to make reasonable
bindings to real time. However, taking into account Linux
architecture problems, which force us to use artificial
integrated clock in any case, this switch is not so bad
for schduling even on high speed networks, though policing
is not reliable.
PSCHED_CPU
It is available only for alpha and pentiums with correct
CPU timestamp. It is the fastest way, use it when it is available,
but remember: not all pentiums have this facility, and
a lot of them have clock, broken by APM etc. etc.
247ace6115