there as "kern.ipc.sendfile.readahead".
- Push all nsfbuf related tunables into MD code. Don't move them
to new namespace in favor of POLA.
Reviewed by: scottl
Approved by: re (gjb)
Previous change applied in r255613 fixed build for ARMv6 but
broke it for previous architecture revisions. This commit
eventually fixes GCC build for all ARM revisions.
Approved by: cognet (mentor)
Approved by: re (kib)
pmap_clear_reference() has had exactly one caller in the kernel for
several years, more precisely, since FreeBSD 8. Now, that call no
longer exists.
Approved by: re (kib)
Sponsored by: EMC / Isilon Storage Division
While here, correct all consumers to pass NULL instead of 0 as we pass
capability rights as pointers now, not uint64_t.
Reported by: Daniel Peyrolon
Tested by: Daniel Peyrolon
Approved by: re (marius)
Apply the given advice to the specified range of addresses within the
given pmap. Depending on the advice, clear the referenced and/or
modified flags in each mapping. Superpage within the given range will
be demoted or destroyed.
Reviewed by: alc
Approved by: cognet (mentor)
Approved by: re
When clearing the modification status of the superpage, one of the
base pages produced during demotion should be marked as write disabled.
The intention is that subsequent write access may repromote.
In the current implementation this was done wrong as write permission was
granted instead of forbidden.
Approved by: cognet (mentor)
Approved by: re
for ARM.
This is quite ugly, because it has to work around a clang bug that does not
allow built-in functions to be defined, even when they're ones that are
expected to be built as part of a library.
Reviewed by: ed
MADV_DONTNEED) and madvise(..., MADV_FREE). Specifically, introduce a new
pmap function, pmap_advise(), that operates on a range of virtual addresses
within the specified pmap, allowing for a more efficient implementation of
MADV_DONTNEED and MADV_FREE. Previously, the implementation of
MADV_DONTNEED and MADV_FREE relied on per-page pmap operations, such as
pmap_clear_reference(). Intuitively, the problem with this implementation
is that the pmap-level locks are acquired and released and the page table
traversed repeatedly, once for each resident page in the range
that was specified to madvise(2). A more subtle flaw with the previous
implementation is that pmap_clear_reference() would clear the reference bit
on all mappings to the specified page, not just the mapping in the range
specified to madvise(2).
Since our malloc(3) makes heavy use of madvise(2), this change can have a
measureable impact. For example, the system time for completing a parallel
"buildworld" on a 6-core amd64 machine was reduced by about 1.5% to 2.0%.
Note: This change only contains pmap_advise() implementations for a subset
of our supported architectures. I will commit implementations for the
remaining architectures after further testing. For now, a stub function is
sufficient because of the advisory nature of pmap_advise().
Discussed with: jeff, jhb, kib
Tested by: pho (i386), marcel (ia64)
Sponsored by: EMC / Isilon Storage Division
Promoting base pages to superpages can increase TLB coverage and allow for
efficient use of page table entries. This development provides FreeBSD/ARM
with superpages management mechanism roughly equivalent to what we have for
i386 and amd64 architectures.
1. Add mechanism for automatic promotion of 4KB page mappings to 1MB section
mappings (and demotion when not needed, respectively).
2. Managed and non-kernel mappings are now superpages-aware.
3. The functionality can be enabled by setting "vm.pmap.sp_enabled" tunable to
a non-zero value (either in loader.conf or by modifying "sp_enabled"
variable in pmap-v6.c file). By default, automatic promotion is currently
disabled.
Submitted by: Zbigniew Bodek <zbb@semihalf.com>
Reviewed by: alc
Sponsored by: The FreeBSD Foundation, Semihalf
This allows for enabling and configuring superpages reservation mechanism in
order to allocate and populate 256 4KB base pages (for the purpose of
promotion to a 1MB superpage).
Submitted by: Zbigniew Bodek <zbb@semihalf.com>
Reviewed by: alc
Sponsored by: The FreeBSD Foundation, Semihalf
which is the part of struct vmspace, allocated from UMA_ZONE_NOFREE
zone. Initialize the pmap lock in the vmspace zone init function, and
remove pmap lock initialization and destruction from pmap_pinit() and
pmap_release().
Suggested and reviewed by: alc (previous version)
Tested by: pho
Sponsored by: The FreeBSD Foundation
The TI uart hardware is ns16550-compatible, except that before it can
be used the clocks and power have to be enabled and a non-standard
mode control register has to be set to put the device in uart mode
(as opposed to irDa or other serial protocols). This adds the extra
code in an extension to the standard ns8250 probe routine, and the
rest of the driver is just the standard ns8250 code.
The MMCHS hardware is pretty much a standard SDHCI v2.0 controller with a
couple quirks, which are now supported by sdhci(4) as of r254507.
This should work for all TI SoCs that use the MMCHS hardware, but it has
only been tested on AM335x right now, so this enables it on those platforms
but leaves the existing ti_mmchs driver in place for other OMAP variants
until they can be tested.
This initial incarnation lacks DMA support (coming soon). Even without it
this improves performance pretty noticibly over the ti_mmchs driver,
primarily because it now does multiblock IO.
There is no need for calling vm_page_dirty() when clearing "modified" flag as
it is already set for that page in pmap_fault_fixup() or pmap_enter() thanks
to "modified" bit emulation.
Also, there is no need for checking PTE "referenced" or "writeable" flags. If
there is a request to clear a particular flag we should just do it.
Submitted by: Zbigniew Bodek <zbb@semihalf.com>
Reviewed by: gber
Sponsored by: The FreeBSD Foundation, Semihalf
Last input argument in pmap_modify_pv() should be a mask of flags to be set.
In pmap_change_wiring() however, the straight wired status was used, which
does not represent valid flags (and is of type boolean).
This commit fixes the issue so that wired flag is passed to pmap_modify_pv()
properly.
Submitted by: Zbigniew Bodek <zbb@semihalf.com>
Reviewed by: gber
Sponsored by: The FreeBSD Foundation, Semihalf
Revise L2_S_PROT_MASK to include all of the protection bits. Notice that
clearing these bits does not always take away the corresponding permissions
(for example, permission is granted when the bit is cleared). The bits are
cleared but are to be set or left cleared accordingly in pmap_set_prot(),
pmap_enter_locked(), etc.
Clear L2_XN along with L2_S_PROT_MASK in pmap_set_prot() so that all
permissions related bits are cleared before actual configuration.
Submitted by: Zbigniew Bodek <zbb@semihalf.com>
Reviewed by: gber
Sponsored by: The FreeBSD Foundation, Semihalf
- PGA_WRITEABLE indicates that there *might be* a writable mapping for the
particular page, so to avoid frequent sweeping of the pv_entries whenever
pmap_nuke_pv(), pmap_modify_pv(), etc. is called, it is sufficient to
clear that flag if there are no managed mappings for that page anymore
(notice that only pmap_enter is authorized to set this flag).
- Avoid redundant checking for PVF_WIRED flag when this flag cannot be set
anyway.
- Clear PGA_WRITEABLE only once for each vm_page instead of multiple,
redundant clearing it in loop when there are no writeable mappings
to that page anymore.
Submitted by: Zbigniew Bodek <zbb@semihalf.com>
Reviewed by: gber
Sponsored by: The FreeBSD Foundation, Semihalf
