status of autotuning freebsd for 9.2

Andre Oppermann andre at
Mon Jul 8 14:37:09 UTC 2013

On 07.07.2013 20:24, Alfred Perlstein wrote:
> On 7/7/13 1:34 AM, Andre Oppermann wrote:
>> Can you help me with with testing?
> Yes.  Please give me your proposed changes and I'll stand up a machine and give feedback.

This is functional bundle MFC of these original commits:

MFC r242029 (alfred):

  Allow autotune maxusers > 384 on 64 bit machines.

MFC r242847 (alfred):

  Allow maxusers to scale on machines with large address space.

MFC r243631 (andre):

  Base the mbuf related limits on the available physical memory or
  kernel memory, whichever is lower.  The overall mbuf related memory
  limit must be set so that mbufs (and clusters of various sizes)
  can't exhaust physical RAM or KVM.

  At the same time divorce maxfiles from maxusers and set maxfiles to
  physpages / 8 with a floor based on maxusers.  This way busy servers
  can make use of the significantly increased mbuf limits with a much
  larger number of open sockets.

MFC r243639 (andre):

  Complete r243631 by applying the remainder of kern_mbuf.c that got
  lost while merging into the commit tree.

MFC r243668 (andre):

  Using a long is the wrong type to represent the realmem and maxmbufmem
  variable as they may overflow on i386/PAE and i386 with > 2GB RAM.

MFC r243995, r243996, r243997 (pjd):

  Style cleanups, Make use of the fact that uma_zone_set_max(9) already
  returns actual limit set.

MFC r244080 (andre):

  Prevent long type overflow of realmem calculation on ILP32 by forcing
  calculation to be in quad_t space.  Fix style issue with second parameter
  to qmin().

MFC r245469 (alfred):

  Do not autotune ncallout to be greater than 18508.

MFC r245575 (andre):

  Move the mbuf memory limit calculations from init_param2() to
  tunable_mbinit() where it is next to where it is used later.

MFC r246207 (andre):

  Remove unused VM_MAX_AUTOTUNE_NMBCLUSTERS define.

MFC r249843 (andre):

  Base the calculation of maxmbufmem in part on kmem_map size
  instead of kernel_map size to prevent kernel memory exhaustion
  by mbufs and a subsequent panic on physical page allocation


More information about the freebsd-stable mailing list