use pmap_is_referenced rather than pmap_clear_reference.
we don't need to clear the bit here as we'll do so when
moving pages back to inactive queue again. pointed by Chuck Silvers.
already-copied pages are paged out. anons that have already been copied
will have refcount == 1, whereas anons that still need to be copied will
have refcount > 1. fixes PR 25392, PR 30257, PR 31924.
not running on the same CPU as the swapper. l_stat is protected by
sched_lock, which isn't held here, so we can race with that lwp
starting to run and see its l_cpu not updated yet, as in PR 31870.
we check l_stat again in uvm_swapout() while holding sched_lock,
so the race itself is harmless.
- rather than embedding bufq_state in driver softc,
have a pointer to the former.
- move bufq related functions from kern/subr_disk.c to kern/subr_bufq.c.
- rename method to strategy for consistency.
- move some definitions which don't need to be exposed to the rest of kernel
from sys/bufq.h to sys/bufq_impl.h.
(is it better to move it to kern/ or somewhere?)
- fix some obvious breakage in dev/qbus/ts.c. (not tested)
- genfs_putpages: wait for i/o completion of PG_RELEASED/PG_PAGEOUT pages by
setting "wasclean" false when encountering them.
suggested by Stephan Uphoff in PR/24596 (1).
- genfs_putpages: write protect pages when cleaning out, if
we're going to take the vnode off the syncer's queue.
uvm_fault: don't write-map pages unless its vnode is already on
the syncer's queue.
fix PR/24596 (3) but in the different way from the suggested fix.
(to keep our current behaviour, ie. not to require explicit msync.
discussed on tech-kern@.)
- genfs_putpages: don't mistakenly take a vnode off the queue
by introducing a generation number in genfs_node.
genfs_getpages: increment the generation number.
suggested by Stephan Uphoff in PR/24596 (2).
- add some assertions.
to prevent unnecessary block allocations in the case that
page size > block size.
- ufs_balloc_range: use VM_PROT_WRITE+PGO_NOBLOCKALLOC rather than
VM_PROT_READ.
i/o is done. Instead, pass an opaque cookie which is then passed to a
new routine, coredump_write, which does the actual i/o. This allows the
method of doing i/o to change without affecting any future MD code.
Also, make netbsd32_core.c [re]use core_netbsd.c (in a similar manner that
core_elf64.c uses core_elf32.c) and eliminate that code duplication.
cpu_coredump{,32} is now called twice, first with a NULL iocookie to fill
the core structure and a second to actually write md parts of the coredump.
All i/o is nolonger random access and is suitable for shipping over a stream.
protection does not include VM_PROT_READ, so that the core dumping
doesn't error out with EFAULT when trying to write that region.
Addresses PR kern/30143; approach suggested by chs@.
little or no swap.
- even on a severe swap shortage, if we have some amount of file-backed pages,
don't bother to kill processes.
- if all pages in queue will be likely reactivated, just give up
page type balancing rather than spinning unnecessarily.
fix "warning: resource shortage: %d pages of swap lost".
extent(9) has some undesirable characteristics for swap allocation:
- it involves alloc-to-free.
- its operational cost is O(n*n) where n is number of entries.
- don't use managed mappings/backing objects for wired memory allocations.
save some resources like pv_entry. also fix (most of) PR/27030.
- simplify kernel memory management API.
- simplify pmap bootstrap of some ports.
- some related cleanups.
* For sparc64 and amd64, define *SIZ32 VM constants.
* Add a new function pointer to struct emul, pointing at a function
that will return the default VM map address. The default function
is uvm_map_defaultaddr, which just uses the VM_DEFAULT_ADDRESS
macro. This gives emulations control over the default map address,
and allows things to be mapped at the right address (in 32bit range)
for COMPAT_NETBSD32.
* Add code to adjust the data and stack limits when a COMPAT_NETBSD32
or COMPAT_SVR4_32 binary is executed.
* Don't use USRSTACK in kern_resource.c, use p_vmspace->vm_minsaddr
instead (emulations might have set it differently)
* Since this changes struct emul, bump kernel version to 3.99.2
Tested on amd64, compile-tested on sparc64.
define and use vm_map_set{min,max}() for modifying these values.
remove the {min,max}_offset aliases for these vm_map fields to be more
namespace-friendly. PR 26475.
to four (adding size and direction).
In order for topdown uvm to be an option on ports using PMAP_PREFER,
they will need to "prefer" lower addresses if topdown is being used.
Additionally, at least one port also needs to know the size.
yamt