This is in preparation for merging the new rx history code written by Gerrit Renker.
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>
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 patch changes the tfrc_lib module in the following manner:
(1) a dedicated tfrc source file to call the packet history &
loss interval init/exit functions.
(2) a dedicated tfrc_pr_debug macro with toggle switch `tfrc_debug'.
Commiter note: renamed tfrc_module.c to tfrc.c, and made CONFIG_IP_DCCP_CCID3
select IP_DCCP_TFRC_LIB.
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>
Based on a previous patch by Gerrit Renker.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch was based on another made by Gerrit Renker, his changelog was:
------------------------------------------------------
The patch set migrates TFRC TX history to a singly-linked list.
The details are:
* use of a consistent naming scheme (all TFRC functions now begin with `tfrc_');
* allocation and cleanup are taken care of internally;
* provision of a lookup function, which is used by the CCID TX infrastructure
to determine the time a packet was sent (in turn used for RTT sampling);
* integration of the new interface with the present use in CCID3.
------------------------------------------------------
Simplifications I did:
. removing the tfrc_tx_hist_head that had a pointer to the list head and
another for the slabcache.
. No need for creating a slabcache for each CCID that wants to use the TFRC
tx history routines, create a single slabcache when the dccp_tfrc_lib module
init routine is called.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This removes a comment which identifies an `issue' with dccp_write_xmit() where there is none.
The comment assumes it is possible that a packet is sent between the calls to
ccid_hc_tx_send_packet(),
dccp_transmit_skb(),
ccid_hc_tx_packet_sent()
(in the above order) in dccp_write_xmit().
I think that this is impossible, since dccp_write_xmit() is always called under lock:
* when called as dccp_write_xmit(sk, 1) from dccp_send_close(), the socket is locked
(see code comment above dccp_send_close());
* when called as dccp_write_xmit(sk, 0) from dccp_send_msg(), it is after lock_sock() has been called;
* when called as dccp_write_xmit(sk, 0) from dccp_write_xmit_timer(), bh_lock_sock() has been called
and the if/else statement has made sure that sk_lock.owner is not set;
* there are no other places where dccp_write_xmit() is called.
Furthermore, the debug statement for printing the sequence number of the packet just sent has been
removed, since the entire list is being printed anyway and so the entry of that number appears last.
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>
The code used two different variables to count Acks, one of them redundant.
This patch reduces the number of Ack counters to one.
The type of the Ack counter has also been changed to u32 (twice the range of int);
and the variable has been renamed into `packets_acked' - for consistency with
RFC 3465 (and similarly named variables are used by TCP and SCTP).
Lastly, a slightly less aggressive `maxincr' increment is used (for even Ack Ratios,
maxincr was Ack Ratio/2 + 1 instead of Ack Ratio/2).
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 the synchronisation variable `ccid2hctx_sendwait', which is set to 1
when the CCID2 sender may send a new packet, and which is set to 0 otherwise
The variable is redundant, since it is only used in combination with the hc_tx_send_packet/
hc_tx_packet_sent function pair. Both functions are called under socket lock, so the
following happens when the CCID2 may send a new packet:
* it sets sendwait = 1 in tx_send_packet and returns 0;
* the subsequent call to tx_packet_sent clears the sendwait flag;
* since tx_send_packet returns 0 if and only if sendwait == 1, the BUG_ON condition
in tx_packet_sent is never satisfied, since that function is never called when
tx_send_packet returns a value different from 0 (cf. dccp_write_xmit);
* the call to tx_packet_sent clears the flag so that the condition "!sendwait" is
true the next time tx_packet_sent is called.
In other words, it is sufficient to just return 0 / not-0 to synchronise tx_send_packet
and tx_packet_sent -- which is what the patch does.
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 reduces the amount of redundant debugging messages:
* pipe/cwnd are printed in both tx_send_packet() and tx_packet_sent().
Both functions are called immediately after one another, so one occurrence is sufficient.
* Since tx_packet_sent() prints pipe/cwnd already, the second printk for pipe is redundant.
* In tx_packet_sent() the check_sanity function is called twice (at the begin and at the end).
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>
The function ccid2_change_pipe only does an assignment. This patch simplifies the code by
replacing the function with the assignment it performs.
Furthermore, the type of pipe is promoted from `signed' to unsigned (increasing the range).
As a result, a BUG_ON test for negative values now becomes obsolete (for safety not removed,
but replaced with a less annoying `DCCP_BUG').
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 current function ccid2_change_cwnd in effect makes only an assignment, as
the test whether cwnd has reached 0 is only required when cwnd is halved.
This patch simplifies the code by replacing the function with the assignment
it performs.
Furthermore, since ssthresh derives from cwnd and appears in many assignments and
comparisons, the type of ssthresh has also been changed to match that of cwnd.
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 field member `numdupack', which was used as a read-only
constant in the code, with a #define.
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 removes a variable `ccid2hctx_sent' which is incremented but
never referenced/read (i.e., dead code).
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 comments out a problematic section comprising a half-finished algorithm:
- The variable `ccid2hctx_ackloss' is never initialised to a value different from 0 and
hence in fact is a read-only constant.
- The `arsent' variable counts packets other than Acks (it is incremented for every packet),
and there is no test for Ack Loss.
- The concept of counting Acks as such leads to a complex calculation, and the calculation
at the moment is inconsistent with this concept.
The problem is that the number of Acks - rather than the number of windows - is counted,
which leads to a complex (cubic/quadratic) expression - this is not even implemented.
In its current state, the commented-out algorithm interfers with normal processing by
changing Ack Ratio incorrectly, and at the wrong times.
A new algorithm is necessary, which will not necessarily use the same variables as used by
the unfinished one; hence the old variables have been removed.
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>
RFC 4341, sec. 5 states that "The cwnd parameter is initialized to at most
four packets for new connections, following the rules from [RFC3390]", which
is implemented 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 patch removes a bug in the current code. I agree with Andrea's comment
that there is a problem here but the way it is treated does not fix it.
The problem is that whenever Ack Ratio > cwnd, starvation/deadlock occurs:
* the receiver will not send an Ack until (Ack Ratio - cwnd) data packets
have arrived;
* the sender will not send any data packet before the receipt of an Ack
advances the send window.
The only way that the connection then progresses was via RTO timeout. In one
extreme case (bulk transfer), it was observed that this happened for every single
packet; i.e. hundreds of packets, each a RTO timeout of 1..3 seconds apart:
a transfer which normally would take a fraction of a second thus grew to
several minutes.
The solution taken by this approach is to observe the relation
"Ack Ratio <= cwnd"
by using the constraint (1) from RFC 4341, 6.1.2; i.e. set
Ack Ratio = ceil(cwnd / 2)
and update it whenever either Ack Ratio or cwnd change. This ensures that
the deadlock problem can not arise.
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 it makes not sense to assign negative values to Ack Ratio, this
patch disallows this possibility.
As a consequence, a Bug test for negative Ack Ratio values becomes obsolete.
Furthermore, a check against overflow (as Ack Ratio may not exceed 2 bytes,
due to RFC 4340, 11.3) has been added.
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 replaces use of normal subtraction with modulo-48 subtraction.
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>
In CCID2 the receiver-history is sorted in ascending order of sequence number,
but the processing of received Ack Vectors requires the list traversal in the
opposite direction.
The current code has a bug in this regard: the list traversal is upwards. As a
consequence, only Ack Vectors with a run length of 1 will pass, in all other
Ack Vectors the remaining (acked) sequence numbers are missed, and may later
falsely be identified as lost.
Note: This bug is only visible when Ack Ratio > 1, since otherwise the run
lengths of Ack Vectors are 0.
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 cleans up the consequences of an earlier patch which
introduced the `if IP_DCCP' clause into net/dccp/Kconfig.
The CCID Kconfig menu is sourced within this clause; as a
consequence, all tests of type `depends on IP_DCCP' are now
redundant.
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 patch addresses the following problems:
1. DCCP relies for its proper functioning on having at least one CCID module
enabled (as in TCP plugable congestion control). Currently it is possible to
disable both CCIDs and thus leave the DCCP module in a compiled, but entirely
non-functional state: no sockets can be created when no CCID is available.
Furthermore, the protocol is (again like TCP) not intended to be used without
CCIDs. Last, a non-empty CCID list is needed for doing CCID feature negotiation.
2. Internally the default CCID that is advertised by the Linux host is set to CCID2
(DCCPF_INITIAL_CCID in include/linux/dccp.h). Disabling CCID2 in the Kconfig
menu without changing the defaults leads to a failure `module not found' when
trying to load the dccp module (which internally tries to load the default CCID).
3. The specification (RFC 4340, sec. 10) treats CCID2 somewhat like a
`minimum common denominator'; the specification says that:
* "New connections start with CCID 2 for both endpoints"
* "A DCCP implementation intended for general use, such as an implementation in a
general-purpose operating system kernel, SHOULD implement at least CCID 2.
The intent is to make CCID 2 broadly available for interoperability [...]"
Providing CCID2 as minimum-required CCID (like Reno/Cubic in TCP) thus seems reasonable.
Hence this patch automatically selects CCID2 when DCCP is enabled. Documentation also added.
Discussions with Ian McDonald on this subject are gratefully acknowledged.
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 moving average computation occurs so frequently in the CCID 3 code that
it merits an inline function of its own. This is uses a suggestion by
Arnaldo as per http://www.mail-archive.com/dccp@vger.kernel.org/msg01662.html
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 fixes/updates the handling of idle and application-limited periods in CCID3,
which currently is broken: there is no detection as to how long a sender has been
idle - there is only one flag which is toggled in between function calls.
Being obsolete now, the `idle' flag is removed.
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 patch fixes a previously undiscovered bug; the problem is in computing
the elapsed time as the time between `receiving' the packet (i.e. skb enters
CCID module) and sending feedback:
- there is no layer-processing, queueing, or delay involved,
- hence the elapsed time is in the order of 1 function call
- this is in the dimension of maximally 50..100usec
- which renders the use of elapsed time almost entirely useless.
The fix is simply to ignore such trivial amounts of elapsed time.
As a further advantage, the now useless elapsed_time field can be removed from
the socket, which reduces the socket structure by another four bytes.
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 updates the CCID3 code with regard to two instances of using `MSS' in place of `s':
1. The RFC3390-based initial rate: both rfc3448bis as well as the Faster Restart
draft now consistently use `s' instead of MSS.
2. Now agrees with section 4.2 of rfc3448bis: "If the sender is ready to send data when
it does not yet have a round trip sample, the value of X is set to s bytes per
second, for segment size s [...]"
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>
Many-many code in the kernel initialized the timer->function
and timer->data together with calling init_timer(timer). There
is already a helper for this. Use it for networking code.
The patch is HUGE, but makes the code 130 lines shorter
(98 insertions(+), 228 deletions(-)).
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Assigning initial values of `0' is redundant when loading a new CCID structure,
since in net/dccp/ccid.c the entire CCID structure is zeroed out prior to
initialisation in ccid_new():
struct ccid {
struct ccid_operations *ccid_ops;
char ccid_priv[0];
};
// ...
if (rx) {
memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
goto out_free_ccid;
} else {
memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
/* analogous to the rx case */
}
This patch therefore removes the redundant assignments. Thanks to Arnaldo for
the inspiration.
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>
This fixes `unaligned (read) access' errors of the type
Kernel unaligned access at TPC[100f970c] dccp_parse_options+0x4f4/0x7e0 [dccp]
Kernel unaligned access at TPC[1011f2e4] ccid3_hc_tx_parse_options+0x1ac/0x380 [dccp_ccid3]
Kernel unaligned access at TPC[100f9898] dccp_parse_options+0x680/0x880 [dccp]
by using the get_unaligned macro for parsing options.
Commiter note: Preserved the sparse __be{16,32} annotations.
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>
This replaces several uses of standard arithmetic with the DCCP
sequence number arithmetic functions. The problem here is that the
sequence number wrap-around was not taken into consideration.
* Condition "seqp->ccid2s_seq <= prev->ccid2s_seq" has been replaced
by
dccp_delta_seqno(seqp->ccid2s_seq, prev->ccid2s_seq) >= 0
since if seqp is `before' prev, then the delta_seqno() is positive.
* The test whether sequence numbers `a' and `b' are consecutive has
the form
dccp_delta_seqno(a, b) == 1
* Increment of ccid2hctx_rpseq could be done using dccp_inc_seqno(),
but since here the incremented ccid2hctx_rpseq == seqno, used
assignment instead.
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>
skb's passed to ccid2_hc_tx_send_packet() are headerless, the packet
type is decided later, in dccp_write_xmit(). Therefore the first test
of the switch/case block is always true, the others are never reached.
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 removes a test for `val < 1' which would only have been triggered
when val < 0, due to a preceding test for 0. Fixed by using an
unsigned type for cwnd (as in TCP) instead.
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 removes an ugly BUG_ON which has been pointed out by Arnaldo.
Instead of freezing up the machine, a `critical' message is now issued
to the system log.
There is potential of doing this more gracefully (eg. there are a few
internal variables which could be updated despite the lack of memory),
but that requires more complicated changes to the algorithm; thus a
`FIXME' has been added.
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 patch simplifies the interface of ccid2_hc_tx_alloc_seq():
* ccid2_hc_tx_alloc_seq() is always called with an argument of
CCID2_SEQBUF_LEN;
* other code - ccid2_hc_tx_check_sanity() - even depends on the
assumption that ccid2_hc_tx_alloc_seq() has been called with this
particular size;
* passing the `gfp_t' argument to ccid2_hc_tx_alloc_seq() is
redundant with gfp_any().
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 just sets the parameter to bool, since debugging messages are
either on or off.
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 moves several instances of testing against NULL into the function which is
used to de-reference the CCID-private data.
Committer note: Made the BUG_ON depend on having CONFIG_IP_DCCP_CCID3_DEBUG, as it
is too much to have this on production code. Also made sure that
the macro is used only after checking if sk_state is not LISTEN,
to make it equivalent to what we had before.
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@ghostprotocols.net>
The third parameter of dccp_sample_rtt now becomes useless and is removed.
Also combined the subtraction of the timestamp echo and the elapsed time.
This is safe, since (a) presence of timestamp echo is tested first and (b)
elapsed time is either present and non-zero or it is not set and equals 0
due to the memset in dccp_parse_options.
To avoid measuring option-processing time, the timestamp for measuring the
initial Request/Response RTT sample is taken directly when the function is
called (the Linux implementation always adds a timestamp on the Request,
so there is no loss in doing this).
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@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch reduces the number of timestamps taken in the receive path
for each packet.
The ccid3_hc_tx_update_x() routine is called in
* the receive path for each CCID3-controlled packet
* for the nofeedback timer (if no feedback arrives during 4 RTT)
Currently, when there is no loss, each packet gets timestamped twice.
The patch resolves this by recycling the first timestamp taken on packet
reception for RTT sampling.
When the no_feedback_timer() is called, then the timestamp argument is
simply set to NULL - so that ccid3_hc_tx_update_x() takes care of the logic.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now to convert the ackvec code to ktime_t so that we can get rid of
dccp_timestamp and the epoch thing in dccp_sock.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The code was too complicated, if p > 0 in ccid3_hc_tx_no_feedback_timer the
timestamp was being obtained to be passed to ccid3_hc_tx_update_x, where only
if p > 0 the timestamp was needed, so just leave it to ccid3_hc_tx_update_x to
obtain the timestamp if needed.
This will help in the upcoming changesets where we'll convert t_ld to ktime_t.
We'll eventually try to reuse ktime_get_real() calls again.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.
This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
