DragonFly-2.3.2.83.gf8565 master sys/vfs/nfs nfs.h nfs_bio.c nfs_iod.c nfs_socket.c nfs_vfsops.c nfsm_subs.c nfsm_subs.h nfsmount.h

[Matthew Dillon]

commit f8565b0fd3905ebd9fb24ff83243c0b4cb3c0ea9
Author: Matthew Dillon <dillon at apollo.backplane.com>
Date:   Fri Jul 17 18:25:05 2009 -0700

    NFS - Rewrite the RTT code and the request flags & low level state machine
    
    * The RTT code basically did not work with UDP, and never has very well.
      Use a somewhat different algorithm and make more of an assumption that
      the network is either reliable, or if it isn't reliable that the sysad
      is using a reliable protocol (such as TCP).
    
      The new RTT code should do a better job, though there will still
      be significant stalling on a lossy network if using UDP (too bad!).
    
    * Replace the congestion control code.  Instead of trying to defer
      packet transmission to the nfs_timer, which we no longer run at
      insane rates, we instead limit the number of async BIOs we allow
      to be queued at any given moment.
    
    * Redo the req->r_flags flags and the low level RPC interlocks between
      the various consumers and producers.  Add additional flags that
      can be tested in assertions to validate expectations.
    
      Use R_LOCKED for more then just the nfs_timer code.
    
    * Close a memory hole.
    
    * Hold critical sections to close races that could result in a
      thread deadlocking in soreceive waiting for a reply that another
      thread already processed.
    
    * Add two sysctls to aid in testing.
    
        vfs.nfs.showrexmit	- Causes "X" to be printed on the console whenever
    			  NFS feels that it must retransmit a RPC.  Only
    			  occurs with UDP mounts.
    
        vfs.nfs.showrtt	- Causes NFS to print out the SRTT, SDRTT, and
    			  converted timeout calculation once a second
    			  while NFS requests are active.
    
    * Increase the asynchronous BIO limits.  Because we only need two helper
      threads and no longer depend on dozens of synchronous-rpc threads
      (the old nfsiod's), there is no practical limit to the number of
      requests we can have active.
    
      Reformulate how asynchronous BIOs are accounted for.  They are now
      accounted for from the moment they are queued to the very end where
      they are biodone()'d.

Summary of changes:
 sys/vfs/nfs/nfs.h        |   32 +++-
 sys/vfs/nfs/nfs_bio.c    |   11 +-
 sys/vfs/nfs/nfs_iod.c    |   31 ++-
 sys/vfs/nfs/nfs_socket.c |  548 ++++++++++++++++++++++++++--------------------
 sys/vfs/nfs/nfs_vfsops.c |    3 +-
 sys/vfs/nfs/nfsm_subs.c  |    2 -
 sys/vfs/nfs/nfsm_subs.h  |    2 +-
 sys/vfs/nfs/nfsmount.h   |    7 +-
 8 files changed, 376 insertions(+), 260 deletions(-)

http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/f8565b0fd3905ebd9fb24ff83243c0b4cb3c0ea9


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