1. 15 5月, 2015 7 次提交
    • J
      tipc: improve link congestion algorithm · f21e897e
      Jon Paul Maloy 提交于
      The link congestion algorithm used until now implies two problems.
      
      - It is too generous towards lower-level messages in situations of high
        load by giving "absolute" bandwidth guarantees to the different
        priority levels. LOW traffic is guaranteed 10%, MEDIUM is guaranted
        20%, HIGH is guaranteed 30%, and CRITICAL is guaranteed 40% of the
        available bandwidth. But, in the absence of higher level traffic, the
        ratio between two distinct levels becomes unreasonable. E.g. if there
        is only LOW and MEDIUM traffic on a system, the former is guaranteed
        1/3 of the bandwidth, and the latter 2/3. This again means that if
        there is e.g. one LOW user and 10 MEDIUM users, the  former will have
        33.3% of the bandwidth, and the others will have to compete for the
        remainder, i.e. each will end up with 6.7% of the capacity.
      
      - Packets of type MSG_BUNDLER are created at SYSTEM importance level,
        but only after the packets bundled into it have passed the congestion
        test for their own respective levels. Since bundled packets don't
        result in incrementing the level counter for their own importance,
        only occasionally for the SYSTEM level counter, they do in practice
        obtain SYSTEM level importance. Hence, the current implementation
        provides a gap in the congestion algorithm that in the worst case
        may lead to a link reset.
      
      We now refine the congestion algorithm as follows:
      
      - A message is accepted to the link backlog only if its own level
        counter, and all superior level counters, permit it.
      
      - The importance of a created bundle packet is set according to its
        contents. A bundle packet created from messges at levels LOW to
        CRITICAL is given importance level CRITICAL, while a bundle created
        from a SYSTEM level message is given importance SYSTEM. In the latter
        case only subsequent SYSTEM level messages are allowed to be bundled
        into it.
      
      This solves the first problem described above, by making the bandwidth
      guarantee relative to the total number of users at all levels; only
      the upper limit for each level remains absolute. In the example
      described above, the single LOW user would use 1/11th of the bandwidth,
      the same as each of the ten MEDIUM users, but he still has the same
      guarantee against starvation as the latter ones.
      
      The fix also solves the second problem. If the CRITICAL level is filled
      up by bundle packets of that level, no lower level packets will be
      accepted any more.
      Suggested-by: NGergely Kiss <gergely.kiss@ericsson.com>
      Reviewed-by: NYing Xue <ying.xue@windriver.com>
      Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f21e897e
    • J
      tipc: simplify link supervision checkpointing · cd4eee3c
      Jon Paul Maloy 提交于
      We change the sequence number checkpointing that is performed
      by the timer in order to discover if the peer is active. Currently,
      we store a checkpoint of the next expected sequence number "rcv_nxt"
      at each timer expiration, and compare it to the current expected
      number at next timeout expiration. Instead, we now use the already
      existing field "silent_intv_cnt" for this task. We step the counter
      at each timeout expiration, and zero it at each valid received packet.
      If no valid packet has been received from the peer after "abort_limit"
      number of silent timer intervals, the link is declared faulty and reset.
      
      We also remove the multiple instances of timer activation from inside
      the FSM function "link_state_event()", and now do it at only one place;
      at the end of the timer function itself.
      Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
      Reviewed-by: NYing Xue <ying.xue@windriver.com>
      Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      cd4eee3c
    • J
      tipc: rename fields in struct tipc_link · a97b9d3f
      Jon Paul Maloy 提交于
      We rename some fields in struct tipc_link, in order to give them more
      descriptive names:
      
      next_in_no -> rcv_nxt
      next_out_no-> snd_nxt
      fsm_msg_cnt-> silent_intv_cnt
      cont_intv  -> keepalive_intv
      last_retransmitted -> last_retransm
      
      There are no functional changes in this commit.
      Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
      Reviewed-by: NYing Xue <ying.xue@windriver.com>
      Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a97b9d3f
    • J
      tipc: simplify packet sequence number handling · e4bf4f76
      Jon Paul Maloy 提交于
      Although the sequence number in the TIPC protocol is 16 bits, we have
      until now stored it internally as an unsigned 32 bits integer.
      We got around this by always doing explicit modulo-65535 operations
      whenever we need to access a sequence number.
      
      We now make the incoming and outgoing sequence numbers to unsigned
      16-bit integers, and remove the modulo operations where applicable.
      
      We also move the arithmetic inline functions for 16 bit integers
      to core.h, and the function buf_seqno() to msg.h, so they can easily
      be accessed from anywhere in the code.
      Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
      Reviewed-by: NYing Xue <ying.xue@windriver.com>
      Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      e4bf4f76
    • J
      tipc: simplify include dependencies · a6bf70f7
      Jon Paul Maloy 提交于
      When we try to add new inline functions in the code, we sometimes
      run into circular include dependencies.
      
      The main problem is that the file core.h, which really should be at
      the root of the dependency chain, instead is a leaf. I.e., core.h
      includes a number of header files that themselves should be allowed
      to include core.h. In reality this is unnecessary, because core.h does
      not need to know the full signature of any of the structs it refers to,
      only their type declaration.
      
      In this commit, we remove all dependencies from core.h towards any
      other tipc header file.
      
      As a consequence of this change, we can now move the function
      tipc_own_addr(net) from addr.c to addr.h, and make it inline.
      
      There are no functional changes in this commit.
      Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
      Reviewed-by: NYing Xue <ying.xue@windriver.com>
      Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a6bf70f7
    • J
      tipc: simplify link timer handling · 75b44b01
      Jon Paul Maloy 提交于
      Prior to this commit, the link timer has been running at a "continuity
      interval" of configured link tolerance/4. When a timer wakes up and
      discovers that there has been no sign of life from the peer during the
      previous interval, it divides its own timer interval by another factor
      four, and starts sending one probe per new interval. When the configured
      link tolerance time has passed without answer, i.e. after 16 unacked
      probes, the link is declared faulty and reset.
      
      This is unnecessary complex. It is sufficient to continue with the
      original continuity interval, and instead reset the link after four
      missed probe responses. This makes the timer handling in the link
      simpler, and opens up for some planned later changes in this area.
      This commit implements this change.
      Reviewed-by: NRichard Alpe <richard.alpe@ericsson.com>
      Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
      Reviewed-by: NYing Xue <ying.xue@windriver.com>
      Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      75b44b01
    • J
      tipc: simplify resetting and disabling of bearers · b1c29f6b
      Jon Paul Maloy 提交于
      Since commit 4b475e3f2f8e4e241de101c8240f1d74d0470494
      ("tipc: eliminate delayed link deletion at link failover") the extra
      boolean parameter "shutting_down" is not any longer needed for the
      functions bearer_disable() and tipc_link_delete_list().
      
      Furhermore, the function tipc_link_reset_links(), called from
      bearer_reset()  is now unnecessary. We can just as well delete
      all the links, as we do in bearer_disable(), and start over with
      creating new links.
      
      This commit introduces those changes.
      Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
      Reviewed-by: NYing Xue <ying.xue@windriver.com>
      Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b1c29f6b
  2. 14 5月, 2015 32 次提交
  3. 13 5月, 2015 1 次提交