This allocator uses a binary buddy system with a twist. First and
foremost, this allocator is required to support the implementation of
superpages. As a side effect, it enables a more robust implementation
of contigmalloc(9). Moreover, this reimplementation of
contigmalloc(9) eliminates the acquisition of Giant by
contigmalloc(..., M_NOWAIT, ...).
The twist is that this allocator tries to reduce the number of TLB
misses incurred by accesses through a direct map to small, UMA-managed
objects and page table pages. Roughly speaking, the physical pages
that are allocated for such purposes are clustered together in the
physical address space. The performance benefits vary. In the most
extreme case, a uniprocessor kernel running on an Opteron, I measured
an 18% reduction in system time during a buildworld.
This allocator does not implement page coloring. The reason is that
superpages have much the same effect. The contiguous physical memory
allocation necessary for a superpage is inherently colored.
Finally, the one caveat is that this allocator does not effectively
support prezeroed pages. I hope this is temporary. On i386, this is
a slight pessimization. However, on amd64, the beneficial effects of
the direct-map optimization outweigh the ill effects. I speculate
that this is true in general of machines with a direct map.
Approved by: re
more exposure. The current state of SCTP implementation is
considered to be ready for 32-bit platforms, but still need some
work/testing on 64-bit platforms.
Approved by: re (kensmith)
Discussed with: rrs
making the relevant files standard. This avoids duplication and
makes it easier to override/disable unwanted schemes. Since ARM
doesn't have a DEFAULTS configuration file, leave the source
files for the BSD and MBR partitioning schemes in files.arm for
now.
caches with data caches after writing to memory. This typically
is required to make breakpoints work on ia64 and powerpc. For
those architectures the function is implemented.
- Use sched_throw() rather than replicating the same cpu_throw() code for
each architecture. This also allows the scheduler to use any locking it
may want to.
- Use the thread_lock() rather than sched_lock when preempting.
- The scheduler lock is not required to synchronize release_aps.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
- Rename PCPU_LAZY_INC into PCPU_INC
- Add the PCPU_ADD interface which just does an add on the pcpu member
given a specific value.
Note that for most architectures PCPU_INC and PCPU_ADD are not safe.
This is a point that needs some discussions/work in the next days.
Reviewed by: alc, bde
Approved by: jeff (mentor)
Probabilly, a general approach is not the better solution here, so we should
solve the sched_lock protection problems separately.
Requested by: alc
Approved by: jeff (mentor)
handler is wrapped in a couple of functions - a filter wrapper and an
ithread wrapper. In this case (and just in this case), the filter
wrapper could ask the system to schedule the ithread and mask the
interrupt source if the wrapped handler is composed of just an ithread
handler: modify the "old" interrupt code to make it support
this situation, while the "new" interrupt code is already ok.
Discussed with: jhb
used to return PAGE_SIZE without respect to restrictions of a DMA tag.
This affected all of the busdma load functions that use
_bus_dmamap_loader_buffer() as their back-end.
Reviewed by: scottl
in the sun4v source in order to be able to compile the source which
is shared between sparc64 and sun4v just #include the sparc64
version here instead of duplicating it.
This is based on the approach taken by pc98 headers in order to
compile the source shared between i386 and pc98.
iommureg.h (which already began to bitrot) and iommuvar.h from the
sun4v source and adjust some of the source which is shared between
sparc64 and sun4v as appropriate.
vmcnts. This can be used to abstract away pcpu details but also changes
to use atomics for all counters now. This means sched lock is no longer
responsible for protecting counts in the switch routines.
Contributed by: Attilio Rao <attilio@FreeBSD.org>
VM_PHYSSEG_SPARSE depending on whether the physical address space is
densely or sparsely populated with memory. The effect of this
definition is to determine which of two implementations of
vm_page_array and PHYS_TO_VM_PAGE() is used. The legacy
implementation is obtained by defining VM_PHYSSEG_DENSE, and a new
implementation that trades off time for space is obtained by defining
VM_PHYSSEG_SPARSE. For now, all architectures except for ia64 and
sparc64 define VM_PHYSSEG_DENSE. Defining VM_PHYSSEG_SPARSE on ia64
allows the entirety of my Itanium 2's memory to be used. Previously,
only the first 1 GB could be used. Defining VM_PHYSSEG_SPARSE on
sparc64 allows USIIIi-based systems to boot without crashing.
This change is a combination of Nathan Whitehorn's patch and my own
work in perforce.
Discussed with: kmacy, marius, Nathan Whitehorn
PR: 112194
vm.kmem_size_min. Useful when using ZFS to make sure that vm.kmem size will
be at least 256mb (for example) without forcing a particular value via vm.kmem_size.
Approved by: njl (mentor)
Reviewed by: alc
partitioning class that supports multiple schemes. Current
schemes supported are APM (Apple Partition Map) and GPT.
Change all GEOM_APPLE anf GEOM_GPT options into GEOM_PART_APM
and GEOM_PART_GPT (resp).
The ctlreq interface supports verbs to create and destroy
partitioning schemes on a disk; to add, delete and modify
partitions; and to commit or undo changes made.
headers in .S directly rather than getting to their macros through
genassym.c/assym.s so there are less headers genassym.c has to be
kept in sync with.
While at it fix some stytle(9) bugs (indentation, prototype format,
sort headers, etc) and remove trailing whitespace.
may also reflect a Fireplane/Safari or JBus bus (or a virtual bus which
in turn reflects a JBus bus or something like that...).
- In the both the sparc64 and sun4v bus_machdep.c use __FBSDID.
- Spell SBus the official way in comments.
- Replace hardcoded function names (all of which were actually outdated)
in panic and status strings with __func__.
- Fix whitespace nits.
and friends along with all hacks required to implement them. None of
the drivers currently built (as part of GENERIC, LINT or modules) on
sparc64 or sun4v and none of those we might want to use there in
future uses them, AFAICT there actually never was a driver hooked up
to the sparc64 or sun4v build that correctly used these functions
(and it looks like that due to a bug read{b,w,l}()/write{b,w,l}() and
the other functions working on a memory handle never actually worked on
sun4v). All they ever were good for on sparc64 and sun4v was erroneously
dragging in dependencies on isa(4) in drivers like f.e. dpt(4), si(4)
and syscons(4) in source files that supposedly were bus-neutral and
hiding issues with drivers like f.e. ng_bt3c(4) that used these
functions with busses other than isa(4) and therefore couldn't work on
these platforms.
pmap on i386
- check for change in executable status in pmap_enter
- pmap_qenter and pmap_qremove only need to invalidate the range if one
of the pages has been referenced
- remove pmap_kenter/pmap_kremove as they were only used by pmap_qenter
and pmap_qremove
- in pmap_copy don't copy wired bit to destination pmap
- mpte was unused in pmap_enter_object - remove
- pmap_enter_quick_locked is not called on the kernel_pmap, remove check
- move pmap_remove_write specific logic out of tte_clear_phys_bit
- in pmap_protect check for removal of execute bit
- panic in the presence of a wired page in pmap_remove_all
- pmap_zero_range can call hwblkclr if offset is zero and size is PAGE_SIZE
- tte_clear_virt_bit is only used by pmap_change_wiring - thus it can be
greatly simplified
- pmap_invalidate_page need only be called in tte_clear_phys_bit if there
is a match with flags
- lock the pmap in tte_clear_phys_bit so that clearing the page bits is
atomic with invalidating the page
- these changes result in 100s reduction in buildworld from a malloc backed
disk to a malloc backed disk - ~2.5%
