git: kernel - Improve netbooted root NFS mounts and allow tunable overrides.

[Matthew Dillon]

commit 46bd500112aaa7b655f13023d190d2cdf2d31d44
Author: Matthew Dillon <dillon at apollo.backplane.com>
Date:   Tue Nov 17 18:46:11 2015 -0800

    kernel - Improve netbooted root NFS mounts and allow tunable overrides.
    
    * Add two tunables and set the default read-ahead for netbooted root
      mounts to 4.
    
      nfsroot.iosize	defaults to 8192
      nfsroot.rahead	defaults to 4
    
    * The default iosize must remain 8192 as many NFS servers can't handle
      32768, but if your nfs server is on a DragonFly box you can override it
      in your /boot/loader.conf, setting it to 32768.
    
      With the improved read-ahead default, read performance should improve
      significantly on netbooted root mounts.  With the combination of the new
      default read ahead and nfsroot.iosize=32768, read performance should be
      able to max-out a GigE link (100+ MBytes/sec) (assuming the originating
      storage can push that rate).
    
    * Does not effect add-on nfs mounts in /etc/fstab which already used a
      reasonable read-ahead setting.

Summary of changes:
 sys/platform/pc64/x86_64/autoconf.c      | 20 +++++++++++++++++---
 sys/platform/vkernel64/x86_64/autoconf.c | 20 +++++++++++++++++---
 2 files changed, 34 insertions(+), 6 deletions(-)

http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/46bd500112aaa7b655f13023d190d2cdf2d31d44


-- 
DragonFly BSD source repository