If possible, avoid having to do a transmit softirq when a qdisc
watchdog decides to re-enable. The watchdog routine runs off
a timer, so it is already in the same effective context as
the softirq.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The netem code would call getnstimeofday() and dequeue/requeue after
every packet, even if it was waiting. Avoid this overhead by using
the throttled flag.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In most cases, the next packet will be sent after the
last one. So optimize that case.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The random number generator always generates 32 bit values.
The time values are limited by psched_tdiff_t
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If you setup netem to just delay packets; "tc qdisc ls" will report
the reordering as 100%. Well it's a lie, reorder isn't used unless
gap is set, so just set value to 0 so the output of utility
is correct.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use willy's work in optimizing cube root by having table for small values.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Minor optimization of div64_64. do_div() already does optimization
for the case of 32 by 32 divide, so no need to do it here.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implements a unified, protocol independant rules dumping function
which is capable of both, dumping a specific protocol family or
all of them. This speeds up dumping as less lookups are required.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a new interface to register rtnetlink message
handlers replacing the exported rtnl_links[] array which
required many message handlers to be exported unnecessarly.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
The patch follows the following recommendation made in an erratum to RFC 4342:
"Senders MAY additionally make use of other available RTT measurements,
including those from the initial Request-Response packet exchange."
It implements larger initial windows with regard to this inital RTT measurement,
using the mechanism suggested in draft-ietf-dccp-rfc3448bis, section 4.2.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This replaces the existing occurrences of RTT sampling with
the use of the new function dccp_sample_rtt.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A recurring problem, in particular in the CCID code, is that RTT samples
from packets with timestamp echo and elapsed time options need to be taken.
This service is provided via a new function dccp_sample_rtt in this patch.
Furthermore, to protect against `insane' RTT samples, the sampled value
is bounded between 100 microseconds and 4 seconds - for which u32 is sufficient.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The CCID 3 and TFRC specs (RFC 4342, RFC 3448, draft-3448bis) make frequent
reference to the computation of the RFC-3390 initial sending rate:
1. Initial sending rate when RTT is known (RFC 4342, p. 6)
2. Response to Idle/Application-Limited periods (RFC 4342, 5.1)
This warrants putting the code into its own function, for later code reuse.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This clears the following sparc64 build warnings:
1) warning: format "%ld" expects type "long int", but argument 3 has type "suseconds_t"
2) warning: format "%llu" expects type "long long unsigned int", but argument 3 has type "__u64"
Fixed by using typecast to unsigned. This is argued to be safe, since the quantities, after
de-scaling (factor 2^6) fit all in u32.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds a few more fields of interest to /proc/net/dccpprobe, the following output ensues:
1 2 3 4 5 6 7 8 9 10 11
sec.usec src:sport dst:dport size s rtt p X_calc X_recv X t_ipi
Also made the formatting consistent.
Scripts that go with this can be downloaded from http://139.133.210.30/users/gerrit/dccp/dccp_probe/
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This updates the documentation on CCID3-specific options.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds more detail in the wait_for_ccid packet scheduling loop.
In particular, it informs about (i) when delay is used and (ii) why
a packet is discarded.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently debugging output (when configured) is automatically enabled when
DCCP modules are compiled into the kernel rather than built as loadable modules.
This is not necessary, since the module parameters in this case become kernel
commandline parameters, e.g. DCCP or CCID3 debug output can be enabled for a
static build by appending the following at the boot prompt:
dccp.dccp_debug=1 dccp_ccid3.ccid3_debug=1
This patch therefore does away with the more complicated way of always enabling
debug output for static builds
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This:
1. removes a race condition in the access to the scheduled send time t_nom which
results from allowing asynchronous r/w access to t_nom without locks;
2. updates the inter-packet interval t_ipi = s/X when `s' changes, following a
suggestion by Ian McDonald.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds a few debugging statements to ccid3.c
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This fixes a bug which uses an invalid comparison.
The bug resulted in the use of invalid loss intervals.
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This improves the slow-start phase by using the MSS
(as suggested in RFC 4342, sec. 5) instead of the packet size s.
Also figured out that __u32 is ample resource enough.
After applying, I got the following in the logs:
ccid3_hc_tx_packet_recv: client(f7421700), s=6, MSS=1424, w_init=4380, R_sample=176us, X=24886363
Had the previous variant been used, w_init would have been as low as 24.
Committer note: removed unneeded cast to unsigned long long that was
causing a compiler warning on 64bit architectures.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
No code change at all.
This splits ccid3.c into a RX and a TX section, so that the file has an
organisation similar to the other ones (e.g. packet_history.{h,c}).
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since CCID3 avoids sending 0-byte data packets (cf. ccid3_hc_tx_send_packet),
testing for zero-payload length, as performed by ccid3_hc_tx_update_s, is
redundant - hence removed by this patch.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This removes two ambiguities in employing the new definition of before48,
following the analysis on http://www.mail-archive.com/dccp@vger.kernel.org/msg01295.html
(1) Updating GSR when P.seqno >= S.SWL
With the old definition we did not update when P.seqno and S.SWL are 2^47 apart. To
ensure the same behaviour as with the old definition, this is replaced with the
equivalent condition dccp_delta_seqno(S.SWL, P.seqno) >= 0
(2) Sending SYNC when P.seqno >= S.OSR
Here it is debatable whether the new definition causes an ambiguity: the case is
similar to (1); and to have consistency with the case (1), we use the equivalent
condition dccp_delta_seqno(S.OSR, P.seqno) >= 0
Detailed Justification
The follows48 relation identifies whether 48-bit sequence number
x is the direct successor of y. Currently, it does not handle cases
of the following type correctly:
follows48(0x(prefix)10000LL, 0x(prefix)0FFFFLL)
where prefix is an arbitrary hex sequence of up to 7 digits.
This is fixed by reusing the new dccp_delta_seqno function.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch
* organizes the sequence arithmetic functions into one corner of dccp.h
* performs a small modification of dccp_set_seqno to make it more widely reusable
(now it is safe to use any number, since it performs modulo-2^48 assignment)
* adds functions and generic macros for 48-bit sequence arithmetic:
--48 bit complement
--modulo-48 addition and modulo-48 subtraction
--dccp_inc_seqno now a special case of add48
Constants renamed following a suggestion by Arnaldo.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reducing the number of skb->data direct accesses.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
At that point it is equivalent to what was being used, skb->end - skb->data,
and the need is clearly the one skb_tailroom satisfies.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
