cvs commit: src/sys/dev/md md.c

[Alan Cox]

alc         2005-02-13 21:51:50 UTC

  FreeBSD src repository

  Modified files:
    sys/dev/md           md.c 
  Log:
  Request a CPU private mapping from sf_buf_alloc().  If the swap-backed
  memory disk is larger than the number of available sf_bufs, this improves
  performance on SMPs by eliminating interprocessor TLB shootdowns.  For
  example, with 6656 sf_bufs, the default on my test machine, and a 256MB
  swap-backed memory disk, I see the command
  "dd if=/dev/md0 of=/dev/null bs=64k" achieve ~489MB/sec with the default,
  shared mappings, and ~587MB/sec with CPU private mappings.
  
  Revision  Changes    Path
  1.153     +6 -1      src/sys/dev/md/md.c