01 Nov, 2011

1 commit


09 Sep, 2010

5 commits

  • The trivial amount of memory saved isn't worth the cost of dealing with section
    mismatches.

    Signed-off-by: Zach Brown

    Zach Brown
     
  • We were seeing very nasty bugs due to fundamental assumption the current code
    makes about concurrent work struct processing. The code simpy isn't able to
    handle concurrent connection shutdown work function execution today, for
    example, which is very much possible once a multi-threaded krdsd was
    introduced. The problem compounds as additional work structs are added to the
    mix.

    krdsd is no longer perforance critical now that send and receive posting and
    FMR flushing are done elsewhere, so the safest fix is to move back to the
    single threaded krdsd that the current code was built around.

    Signed-off-by: Zach Brown

    Zach Brown
     
  • rds_send_xmit() was changed to hold an interrupt masking spinlock instead of a
    mutex so that it could be called from the IB receive tasklet path. This broke
    the TCP transport because its xmit method can block and masks and unmasks
    interrupts.

    This patch serializes callers to rds_send_xmit() with a simple bit instead of
    the current spinlock or previous mutex. This enables rds_send_xmit() to be
    called from any context and to call functions which block. Getting rid of the
    c_send_lock exposes the bare c_lock acquisitions which are changed to block
    interrupts.

    A waitqueue is added so that rds_conn_shutdown() can wait for callers to leave
    rds_send_xmit() before tearing down partial send state. This lets us get rid
    of c_senders.

    rds_send_xmit() is changed to check the conn state after acquiring the
    RDS_IN_XMIT bit to resolve races with the shutdown path. Previously both
    worked with the conn state and then the lock in the same order, allowing them
    to race and execute the paths concurrently.

    rds_send_reset() isn't racing with rds_send_xmit() now that rds_conn_shutdown()
    properly ensures that rds_send_xmit() can't start once the conn state has been
    changed. We can remove its previous use of the spinlock.

    Finally, c_send_generation is redundant. Callers can race to test the c_flags
    bit by simply retrying instead of racing to test the c_send_generation atomic.

    Signed-off-by: Zach Brown

    Zach Brown
     
  • Favor "if (foo)" style over "if (foo != NULL)".

    Signed-off-by: Andy Grover

    Andy Grover
     
  • This fits better in connection.c, rather than threads.c.

    Signed-off-by: Andy Grover

    Andy Grover
     

17 Mar, 2010

1 commit


30 Nov, 2009

1 commit


24 Aug, 2009

1 commit


27 Feb, 2009

1 commit

  • While arguably the fact that the underlying transport needs a
    connection to convey RDS's datagrame reliably is not important
    to rds proper, the transports implemented so far (IB and TCP)
    have both been connection-oriented, and so the connection
    state machine-related code is in the common rds code.

    This patch also includes several work items, to handle connecting,
    sending, receiving, and shutdown.

    Signed-off-by: Andy Grover
    Signed-off-by: David S. Miller

    Andy Grover