freebsd with flexible iflib nic queues
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Brian Behlendorf ae6ba3dbe6 Improve meta data performance
Profiling the system during meta data intensive workloads such
as creating/removing millions of files, revealed that the system
was cpu bound.  A large fraction of that cpu time was being spent
waiting on the virtual address space spin lock.

It turns out this was caused by certain heavily used kmem_caches
being backed by virtual memory.  By default a kmem_cache will
dynamically determine the type of memory used based on the object
size.  For large objects virtual memory is usually preferable
and for small object physical memory is a better choice.  See
the spl_slab_alloc() function for a longer discussion on this.

However, there is a certain amount of gray area when defining a
'large' object.  For the following caches it turns out they were
just over the line:

  * dnode_cache
  * zio_cache
  * zio_link_cache
  * zio_buf_512_cache
  * zfs_data_buf_512_cache

Now because we know there will be a lot of churn in these caches,
and because we know the slabs will still be reasonably sized.
We can safely request with the KMC_KMEM flag that the caches be
backed with physical memory addresses.  This entirely avoids the
need to serialize on the virtual address space lock.

As a bonus this also reduces our vmalloc usage which will be good
for 32-bit kernels which have a very small virtual address space.
It will also probably be good for interactive performance since
unrelated processes could also block of this same global lock.
Finally, we may see less cpu time being burned in the arc_reclaim
and txg_sync_threads.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #258
2011-11-03 10:19:21 -07:00
cmd Change sun.com URLs to zfsonlinux.org 2011-10-24 09:52:21 -07:00
config Convert 'if' statements to AS_IF in kernel.m4 2011-09-06 13:20:48 -07:00
dracut Synchronize initramfs and system hostid 2011-09-30 13:31:00 -07:00
etc Use automatic variable in Makefile 2011-09-26 09:22:30 -07:00
include Improve meta data performance 2011-11-03 10:19:21 -07:00
lib Make libefi-created GPT compatible with gptfdisk 2011-09-26 09:44:43 -07:00
man Autogen refresh for udev changes 2011-08-08 16:30:27 -07:00
module Improve meta data performance 2011-11-03 10:19:21 -07:00
patches Add build system 2010-08-31 13:41:27 -07:00
scripts Disable 90-zfs.rules for test suite 2011-10-11 14:45:37 -07:00
udev Move 90-zfs udev rule from dracut to udev/rules.d 2011-08-19 16:26:13 -07:00
.gitignore Ignore unsigned module build products 2010-03-09 14:14:09 -08:00
AUTHORS Add "ashift" property to zpool create 2011-06-17 16:35:49 -07:00
autogen.sh Make autogen.sh executable 2011-07-26 10:15:35 -07:00
ChangeLog Add build system 2010-08-31 13:41:27 -07:00
configure Convert 'if' statements to AS_IF in kernel.m4 2011-09-06 13:20:48 -07:00
configure.ac Fix autoconf variable substitution in init scripts. 2011-08-19 16:26:14 -07:00
COPYING Relocate COPYING+COPYRIGHT, remove README cruft 2008-12-01 15:34:53 -08:00
COPYRIGHT Update COPYRIGHT to reference zpios CDDL exceptions. 2010-05-18 14:25:28 -07:00
DISCLAIMER Update COPYRIGHT and DISCLAIMER. 2010-05-18 10:32:23 -07:00
Makefile.am Move udev rules from /etc/udev to /lib/udev 2011-08-08 16:21:10 -07:00
Makefile.in Autogen refresh for udev changes 2011-08-08 16:30:27 -07:00
META Prep zfs-0.6.0-rc6 tag 2011-10-06 14:10:45 -07:00
OPENSOLARIS.LICENSE Add CDDL license file 2008-12-01 14:49:34 -08:00
README.markdown Fix markdown rendering 2010-09-15 09:09:37 -07:00
zfs_config.h.in Add backing_device_info per-filesystem 2011-08-04 13:37:38 -07:00
zfs-modules.spec.in Include distribution in release 2011-10-19 11:43:27 -07:00
zfs-script-config.sh.in Unconditionally load core kernel modules 2010-11-11 11:38:25 -08:00
ZFS.RELEASE Update to onnv_147 2010-08-26 14:24:34 -07:00
zfs.spec.in Include distribution in release 2011-10-19 11:43:27 -07:00

Native ZFS for Linux! ZFS is an advanced file system and volume manager which was originally developed for Solaris. It has been successfully ported to FreeBSD and now there is a functional Linux ZFS kernel port too. The port currently includes a fully functional and stable SPA, DMU, and ZVOL with a ZFS Posix Layer (ZPL) on the way!

$ ./configure
$ make pkg

Full documentation for building, configuring, and using ZFS can be found at: http://zfsonlinux.org