freebsd-dev/sys/arm
Attilio Rao 89f6b8632c Switch the vm_object mutex to be a rwlock. This will enable in the
future further optimizations where the vm_object lock will be held
in read mode most of the time the page cache resident pool of pages
are accessed for reading purposes.

The change is mostly mechanical but few notes are reported:
* The KPI changes as follow:
  - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK()
  - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK()
  - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK()
  - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED()
    (in order to avoid visibility of implementation details)
  - The read-mode operations are added:
    VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(),
    VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED()
* The vm/vm_pager.h namespace pollution avoidance (forcing requiring
  sys/mutex.h in consumers directly to cater its inlining functions
  using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h
  consumers now must include also sys/rwlock.h.
* zfs requires a quite convoluted fix to include FreeBSD rwlocks into
  the compat layer because the name clash between FreeBSD and solaris
  versions must be avoided.
  At this purpose zfs redefines the vm_object locking functions
  directly, isolating the FreeBSD components in specific compat stubs.

The KPI results heavilly broken by this commit.  Thirdy part ports must
be updated accordingly (I can think off-hand of VirtualBox, for example).

Sponsored by:	EMC / Isilon storage division
Reviewed by:	jeff
Reviewed by:	pjd (ZFS specific review)
Discussed with:	alc
Tested by:	pho
2013-03-09 02:32:23 +00:00
..
allwinner Enable uart driver for A10. 2013-03-01 01:47:11 +00:00
arm Switch the vm_object mutex to be a rwlock. This will enable in the 2013-03-09 02:32:23 +00:00
at91 Eliminate a redundant #include: machine/pmap.h is already included 2013-02-26 07:41:34 +00:00
broadcom/bcm2835 - Reset DMA channel if error occured 2013-03-05 20:00:11 +00:00
compile
conf Build the Raspberry Pi dtb file when building the kernel so we can copy it 2013-03-02 03:23:14 +00:00
econa Eliminate a redundant #include: machine/pmap.h is already included 2013-03-01 19:02:41 +00:00
include Fix stack alignment in the kernel to be on an 8 byte boundary as required 2013-03-06 06:19:56 +00:00
lpc MFcalloutng: 2013-02-28 13:46:03 +00:00
mv MFcalloutng: 2013-02-28 13:46:03 +00:00
s3c2xx0 Eliminate a redundant #include: machine/pmap.h is already included 2013-03-01 19:02:41 +00:00
sa11x0 Eliminate a redundant #include: machine/pmap.h is already included 2013-02-26 07:41:34 +00:00
tegra Merge the FDT versions of initarm. 2012-11-03 22:39:07 +00:00
ti MFcalloutng: 2013-02-28 13:46:03 +00:00
versatile MFcalloutng: 2013-02-28 13:46:03 +00:00
xscale Eliminate a redundant #include: machine/pmap.h is already included 2013-03-01 19:02:41 +00:00