cvs commit: src/sys/dev/mpt mpt_user.c

[John Baldwin]

jhb         2008-07-01 19:48:15 UTC

  FreeBSD src repository

  Modified files:
    sys/dev/mpt          mpt_user.c 
  Log:
  SVN rev 180153 on 2008-07-01 19:48:15Z by jhb
  
  Rework how the mpt_user personality handles buffers for config pages.
  Previously we reused the space in the request buffer after the request
  header to hold config pages during a transaction.  This does not work when
  reading large pages however.  Also, we were already malloc'ing a buffer to
  do a copyin/copyout w/o holding locks that was then copied into/out of the
  request buffer.  Instead, go ahead and use bus dma to alloc a buffer for
  each config page request (and RAID actions that have an associated
  ActionSGE).  This results in fewer data copies and allows for larger sized
  requests.  For now the maximum size of a request is arbitrarily limited to
  16 MB.
  
  MFC after:      2 weeks
  
  Revision  Changes    Path
  1.2       +105 -67   src/sys/dev/mpt/mpt_user.c