freebsd-skq/sys/dev/md
Alan Cox e340fc602b 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.
2005-02-13 21:51:50 +00:00
..
md.c Request a CPU private mapping from sf_buf_alloc(). If the swap-backed 2005-02-13 21:51:50 +00:00