decode. This is to accomodate hardware assist implementations that do not
provide the 'guest linear address' as part of nested page fault collateral.
Submitted by: Anish Gupta (akgupt3 at gmail dot com)
do not map the b_pages pages into buffer_map KVA. The use of the
unmapped buffers eliminate the need to perform TLB shootdown for
mapping on the buffer creation and reuse, greatly reducing the amount
of IPIs for shootdown on big-SMP machines and eliminating up to 25-30%
of the system time on i/o intensive workloads.
The unmapped buffer should be explicitely requested by the GB_UNMAPPED
flag by the consumer. For unmapped buffer, no KVA reservation is
performed at all. The consumer might request unmapped buffer which
does have a KVA reserve, to manually map it without recursing into
buffer cache and blocking, with the GB_KVAALLOC flag.
When the mapped buffer is requested and unmapped buffer already
exists, the cache performs an upgrade, possibly reusing the KVA
reservation.
Unmapped buffer is translated into unmapped bio in g_vfs_strategy().
Unmapped bio carry a pointer to the vm_page_t array, offset and length
instead of the data pointer. The provider which processes the bio
should explicitely specify a readiness to accept unmapped bio,
otherwise g_down geom thread performs the transient upgrade of the bio
request by mapping the pages into the new bio_transient_map KVA
submap.
The bio_transient_map submap claims up to 10% of the buffer map, and
the total buffer_map + bio_transient_map KVA usage stays the
same. Still, it could be manually tuned by kern.bio_transient_maxcnt
tunable, in the units of the transient mappings. Eventually, the
bio_transient_map could be removed after all geom classes and drivers
can accept unmapped i/o requests.
Unmapped support can be turned off by the vfs.unmapped_buf_allowed
tunable, disabling which makes the buffer (or cluster) creation
requests to ignore GB_UNMAPPED and GB_KVAALLOC flags. Unmapped
buffers are only enabled by default on the architectures where
pmap_copy_page() was implemented and tested.
In the rework, filesystem metadata is not the subject to maxbufspace
limit anymore. Since the metadata buffers are always mapped, the
buffers still have to fit into the buffer map, which provides a
reasonable (but practically unreachable) upper bound on it. The
non-metadata buffer allocations, both mapped and unmapped, is
accounted against maxbufspace, as before. Effectively, this means that
the maxbufspace is forced on mapped and unmapped buffers separately.
The pre-patch bufspace limiting code did not worked, because
buffer_map fragmentation does not allow the limit to be reached.
By Jeff Roberson request, the getnewbuf() function was split into
smaller single-purpose functions.
Sponsored by: The FreeBSD Foundation
Discussed with: jeff (previous version)
Tested by: pho, scottl (previous version), jhb, bf
MFC after: 2 weeks
"index". The content of a radix tree leaf, or at least its "key", is not
opaque to the other radix tree operations. Specifically, they know how to
extract the "key" from a leaf. So, eliminating the parameter "index" isn't
breaking the abstraction. Moreover, eliminating the parameter "index"
effectively prevents the caller from passing an inconsistent "index" and
leaf to vm_radix_insert().
Reviewed by: attilio
Sponsored by: EMC / Isilon Storage Division
This can be done by using the new macros VMM_STAT_INTEL() and VMM_STAT_AMD().
Statistic counters that are common across the two are defined using VMM_STAT().
Suggested by: Anish Gupta
Discussed with: grehan
Obtained from: NetApp
pages around, taking array of vm_page_t both for source and
destination. Starting offsets and total transfer size are specified.
The function implements optimal algorithm for copying using the
platform-specific optimizations. For instance, on the architectures
were the direct map is available, no transient mappings are created,
for i386 the per-cpu ephemeral page frame is used. The code was
typically borrowed from the pmap_copy_page() for the same
architecture.
Only i386/amd64, powerpc aim and arm/arm-v6 implementations were
tested at the time of commit. High-level code, not committed yet to
the tree, ensures that the use of the function is only allowed after
explicit enablement.
For sparc64, the existing code has known issues and a stab is added
instead, to allow the kernel linking.
Sponsored by: The FreeBSD Foundation
Tested by: pho (i386, amd64), scottl (amd64), ian (arm and arm-v6)
MFC after: 2 weeks
mapping replaces is added to an ordered collection of page table pages.
Rather than preserving the code that implements the splay tree of pages
in the pmap for just this one purpose, use the new MI radix tree. The
extra overhead of using a radix tree for this purpose is small enough,
about 4% added run-time to pmap_promote_pde(), that I don't see the point
of preserving the splay tree code.
will prevent the kernel from linking if the device driver are included
without the virtio module. Remove pci and scbus for the same reason.
Also explain the relationship and necessity of the virtio and virtio_pci
modules. Currently in FreeBSD, we only support VirtIO PCI, but it could
be replaced with a different interface (like MMIO) and the device
(network, block, etc) will still function.
Requested by: luigi
Approved by: grehan (mentor)
MFC after: 3 days
tunable by default.
This will allow GENERIC configurations to boot on small memory boxes, but
not require end users who want to use CTL to recompile their kernel. They
can simply set kern.cam.ctl.disable=0 in loader.conf.
The eventual solution to the memory usage problem is to change the way
CTL allocates memory to be more configurable, but this should fix things
for small memory situations in the mean time.
UPDATING: Explain the change in the CTL configuration, and
how users can enable CTL if they would like to use
it.
sys/conf/options: Add a new option, CTL_DISABLE, that prevents CTL
from initializing.
ctl.c: If CTL_DISABLE is turned on, don't initialize.
i386/conf/GENERIC,
amd64/conf/GENERIC: Re-enable device ctl, and add the CTL_DISABLE
option.
Rename the pv_entry_t iterator from pv_list to pv_next.
Besides being more correct technically (as the name seems to suggest
this is a list while it is an iterator), it will also be needed by
vm_radix work to avoid a nameclash on macro expansions.
Sponsored by: EMC / Isilon storage division
Reviewed by: alc, jeff
Tested by: flo, pho, jhb, davide
It unfortunately steals a fair chunk of RAM at startup even if it's not
actively used, which prevents FreeBSD VMs of 128MB from successfully
booting and running.
When CPU becomes idle, cpu_idleclock() calculates time to the next timer
event in order to reprogram hw timer. Return that time in sbintime_t to
the caller and pass it to acpi_cpu_idle(), where it can be used as one
more factor (quite precise) to extimate furter sleep time and choose
optimal sleep state. This is a preparatory change for further callout
improvements will be committed in the next days.
The commmit is not targeted for MFC.
VM_OBJECT_LOCKED() macro is only used to implement a custom version
of lock assertions right now (which likely spread out thanks to
copy and paste).
Remove it and implement actual assertions.
Sponsored by: EMC / Isilon storage division
Reviewed by: alc
Tested by: pho
machine/signal.h and machine/ucontext.h into common x86 includes,
copying from amd64 and merging with i386.
Kernel-only compat definitions are kept in the i386/include/sigframe.h
and i386/include/signal.h, to reduce amd64 kernel namespace pollution.
The amd64 compat uses its own definitions so far.
The _MACHINE_ELF_WANT_32BIT definition is to allow the
sys/boot/userboot/userboot/elf32_freebsd.c to use i386 ELF definitions
on the amd64 compile host. The same hack could be usefully abused by
other code too.
* VM_OBJECT_LOCK and VM_OBJECT_UNLOCK are mapped to write operations
* VM_OBJECT_SLEEP() is introduced as a general purpose primitve to
get a sleep operation using a VM_OBJECT_LOCK() as protection
* The approach must bear with vm_pager.h namespace pollution so many
files require including directly rwlock.h
Prior to this change pinning was implemented via an ioctl (VM_SET_PINNING)
that called 'sched_bind()' on behalf of the user thread.
The ULE implementation of 'sched_bind()' bumps up 'td_pinned' which in turn
runs afoul of the assertion '(td_pinned == 0)' in userret().
Using the cpuset affinity to implement pinning of the vcpu threads works with
both 4BSD and ULE schedulers and has the happy side-effect of getting rid
of a bunch of code in vmm.ko.
Discussed with: grehan
This eliminates the need to recompile the kernel when the default value
of NKPT is not big enough - for e.g. when loading large kernel modules
or memory disk images from the loader.
If NKPT is defined in the kernel configuration file then it overrides the
dynamic calculation.
Reviewed by: alc, kib
- change 'pics' from STAILQ to TAILQ
- ensure that Local APIC is always first in 'pics'
Reviewed by: jhb
Tested by: Sergey V. Dyatko <sergey.dyatko@gmail.com>,
KAHO Toshikazu <kaho@elam.kais.kyoto-u.ac.jp>
MFC after: 12 days
can only be located at the beginning or the end of the BAR.
If the MSI-table is located in the middle of a BAR then we will split the
BAR into two and create two mappings - one before the table and one after
the table - leaving a hole in place of the table so accesses to it can be
trapped and emulated.
Obtained from: NetApp
The maximum length of an environment variable puts a limitation on the
number of passthru devices that can be specified via a single variable.
The workaround is to allow user to specify passthru devices via multiple
environment variables instead of a single one.
Obtained from: NetApp
FreeBSD TCP-level socket options (only the first two are). Instead,
using a mapping function and fail unsupported options as we do for other
socket option levels.
MFC after: 2 weeks
