- v_vflag is protected by the vnode lock and is used when synchronization
with VOP calls is needed.
- v_iflag is protected by interlock and is used for dealing with vnode
management issues. These flags include X/O LOCK, FREE, DOOMED, etc.
- All accesses to v_iflag and v_vflag have either been locked or marked with
mp_fixme's.
- Many ASSERT_VOP_LOCKED calls have been added where the locking was not
clear.
- Many functions in vfs_subr.c were restructured to provide for stronger
locking.
Idea stolen from: BSD/OS
by pmap_qenter() and pmap_qremove() is pointless. In fact, it probably
leads to unnecessary pmap_page_protect() calls if one of these pages is
paged out after unwiring.
Note: setting PG_MAPPED asserts that the page's pv list may be
non-empty. Since checking the status of the page's pv list isn't any
harder than checking this flag, the flag should probably be eliminated.
Alternatively, PG_MAPPED could be set by pmap_enter() exclusively
rather than various places throughout the kernel.
vm_page_sleep_busy() with vm_page_sleep_if_busy(). At the same time,
increase the scope of the page queues lock. (This should significantly
reduce the locking overhead in vm_object_page_remove().)
o Apply some style fixes.
swapped in, we do not have to ask for the scheduler thread to do
that.
- Assert that a process is not swapped out in runq functions and
swapout().
- Introduce thread_safetoswapout() for readability.
- In swapout_procs(), perform a test that may block (check of a
thread working on its vm map) first. This lets us call swapout()
with the sched_lock held, providing a better atomicity.
except for the fact tha they are presently swapped out. Also add a process
flag to indicate that the process has started the struggle to swap
back in. This will be needed for the case where multiple threads
start the swapin action top a collision. Also add code to stop
a process fropm being swapped out if one of the threads in this
process is actually off running on another CPU.. that might hurt...
Submitted by: Seigo Tanimura <tanimura@r.dl.itc.u-tokyo.ac.jp>
vm_page_rename() from vm_object_backing_scan(). vm_page_rename()
also performs vm_page_deactivate() on pages in the cache queues,
making the removed vm_page_deactivate() redundant.
handler in the kernel at the same time. Also, allow for the
exec_new_vmspace() code to build a different sized vmspace depending on
the executable environment. This is a big help for execing i386 binaries
on ia64. The ELF exec code grows the ability to map partial pages when
there is a page size difference, eg: emulating 4K pages on 8K or 16K
hardware pages.
Flesh out the i386 emulation support for ia64. At this point, the only
binary that I know of that fails is cvsup, because the cvsup runtime
tries to execute code in pages not marked executable.
Obtained from: dfr (mostly, many tweaks from me).
the loadav. This is not real load. If you have a nice process running in
the background, pagezero may sit in the run queue for ages and add one to
the loadav, and thereby affecting other scheduling decisions.
when VM_ALLOC_WIRED is specified: set the PG_MAPPED bit in flags.
o In both vm_page_wire() and vm_page_allocate() add a comment saying
that setting PG_MAPPED does not belong there.
that pre-zeroes free pages.
o Remove GIANT_REQUIRED from some low-level page queue functions. (Instead
assertions on the page queue lock are being added to the higher-level
functions, like vm_page_wire(), etc.)
In collaboration with: peter
Use lmin(long, long), not min(u_int, u_int). This is a problem here on
ia64 which has *way* more than 2^32 pages of KVA. 281474976710655 pages
to be precice.
to return a wired page.
o Use VM_ALLOC_WIRED within Alpha's pmap_growkernel(). Also, because
Alpha's pmap_growkernel() calls vm_page_alloc() from within a critical
section, specify VM_ALLOC_INTERRUPT instead of VM_ALLOC_SYSTEM. (Only
VM_ALLOC_INTERRUPT is implemented entirely with a spin mutex.)
o Assert that the page queues mutex is held in vm_page_wire()
on Alpha, just like the other platforms.
vm_page_zero_idle() instead of partially duplicated implementations.
In particular, this change guarantees that the number of free pages
in the free queue(s) matches the global free page count when Giant
is released.
Submitted by: peter (via his p4 "pmap" branch)
