accounting. Use wired memory (which can be limited) for meta-data, and
kmem(9) for string allocations.
Close PR/31944. Fix PR/38361 while here. OK ad@.
These annotations help to mitigate false sharing on multiprocessor
systems.
Variables annotated with __cacheline_aligned are placed into the
.data.cacheline_aligned section in the kernel. Each item in this
section is aligned on a cachline boundary - this avoids false
sharing. Highly contended global locks are a good candidate for
__cacheline_aligned annotation.
Variables annotated with __read_mostly are packed together tightly
into a .data.read_mostly section in the kernel. The idea here is that
we can pack infrequently modified data items into a cacheline and
avoid having to purge the cache, which would happen if read mostly
data and write mostly data shared a cachline. Initialisation variables
are a prime candiate for __read_mostly annotations.
by defining 'options ACPIVERBOSE' in the kernel config file (no change
from current behavior), or it can be loaded at boot time on those
architectures that support the boot loader's "load" command.
ACPIVERBOSE also includes code to dump acpi/wmi data.
by defining 'options MIIVERBOSE' in the kernel config file (no change
from current behavior), or it can be loaded at boot time on those
architectures that support the boot loader's "load" command.
by defining 'options SCSIVERBOSE' in the kernel config file (no change
from current behavior), or it can be loaded at boot time on those
architectures that support the boot loader's "load" command.
The module is built for all architectures, whether or not SCSI or
atapi support exists.
by defining 'options USBVERBOSE' in the kernel config file (no change
from current behavior), or it can be loaded at boot time on those
architectures that support the boot loader's "load" command.
The module is built for all architectures, whether or not USB support
exists.
separate kernel module. Update pci bus attach routine to load the
module (if available) when we're about to start scanning the bus, and
unload the module after the scan is finished.
On architectures which support loading of modules by the boot loader,
the 'pciverbose' module can be loaded and executed without needing to
rebuild the kernel. On all architectures, using 'options PCIVERBOSE'
in the kernel configuration file will create a 'builtin' module which
is functionally equivalent to previous behavior.
XXX Although not nearly as large as the vendor and product tables,
XXX the PCI class and subclass tables might also be offloaded into
XXX the module at a future time.
XXX Cardbus (and possibly other) drivers should also be modified to
XXX load the module before scanning/attaching devices.
Note, config whines about things like:
files.acpi:30: attaching undefined device `apm'
I intentionally was a lazy boy and didn't include a ton of dirt to
keep the hot napalm and riot blasts in the config thread rolling ;)
tested by jruoho (thanks!)
module instruments every function in the kernel with entry and exit
probes. These probes are true zero-effect probes in that they don't
exist in the code until they are enabled. The probes are enabled by
directly patching the function entry and exit points to make jumps into
the dtrace framework.
This gives us over 29,000 trace points in the kernel.
- Separate the suser part of the bsd44 secmodel into its own secmodel
and directory, pending even more cleanups. For revision history
purposes, the original location of the files was
src/sys/secmodel/bsd44/secmodel_bsd44_suser.c
src/sys/secmodel/bsd44/suser.h
- Add a man-page for secmodel_suser(9) and update the one for
secmodel_bsd44(9).
- Add a "secmodel" module class and use it. Userland program and
documentation updated.
- Manage secmodel count (nsecmodels) through the module framework.
This eliminates the need for secmodel_{,de}register() calls in
secmodel code.
- Prepare for secmodel modularization by adding relevant module bits.
The secmodels don't allow auto unload. The bsd44 secmodel depends
on the suser and securelevel secmodels. The overlay secmodel depends
on the bsd44 secmodel. As the module class is only cosmetic, and to
prevent ambiguity, the bsd44 and overlay secmodels are prefixed with
"secmodel_".
- Adapt the overlay secmodel to recent changes (mainly vnode scope).
- Stop using link-sets for the sysctl node(s) creation.
- Keep sysctl variables under nodes of their relevant secmodels. In
other words, don't create duplicates for the suser/securelevel
secmodels under the bsd44 secmodel, as the latter is merely used
for "grouping".
- For the suser and securelevel secmodels, "advertise presence" in
relevant sysctl nodes (sysctl.security.models.{suser,securelevel}).
- Get rid of the LKM preprocessor stuff.
- As secmodels are now modules, there's no need for an explicit call
to secmodel_start(); it's handled by the module framework. That
said, the module framework was adjusted to properly load secmodels
early during system startup.
- Adapt rump to changes: Instead of using empty stubs for securelevel,
simply use the suser secmodel. Also replace secmodel_start() with a
call to secmodel_suser_start().
- 5.99.20.
Testing was done on i386 ("release" build). Spearated module_init()
changes were tested on sparc and sparc64 as well by martin@ (thanks!).
Mailing list reference:
http://mail-index.netbsd.org/tech-kern/2009/09/25/msg006135.html
tested with a DEBUG+DIAGNOSTIC+LOCKDEBUG kernel. To summerise NiLFS, i'll
repeat my posting to tech-kern here:
NiLFS stands for New implementation of Logging File System; LFS done
right they claim :) It is at version 2 now and is being developed by NTT, the
Japanese telecom company and recently put into the linux source tree. See
http://www.nilfs.org. The on-disc format is not completely frozen and i expect
at least one minor revision to come in time.
The benefits of NiLFS are build-in fine-grained checkpointing, persistent
snapshots, multiple mounts and very large file and media support. Every
checkpoint can be transformed into a snapshot and v.v. It is said to perform
very well on flash media since it is not overwriting pieces apart from a
incidental update of the superblock, but that might change. It is accompanied
by a cleaner to clean up the segments and recover lost space.
My work is not a port of the linux code; its a new implementation. Porting the
code would be more work since its very linux oriented and never written to be
ported outside linux. The goal is to be fully interchangable. The code is non
intrusive to other parts of the kernel. It is also very light-weight.
The current state of the code is read-only access to both clean and dirty
NiLFS partitions. On mounting a dirty partition it rolls forward the log to
the last checkpoint. Full read-write support is however planned!
Just as the linux code, mount_nilfs allows for the `head' to be mounted
read/write and allows multiple read-only snapshots/checkpoint mounts next to
it.
By allowing the RW mount at a different snapshot for read-write it should be
possible eventually to revert back to a previous state; i.e. try to upgrade a
system and being able to revert to the exact state prior to the upgrade.
Compared to other FS's its pretty light-weight, suitable for embedded use and
on flash media. The read-only code is currently 17kb object code on
NetBSD/i386. I doubt the read-write code will surpass the 50 or 60. Compared
this to FFS being 156kb, UDF being 84 kb and NFS being 130kb. Run-time memory
usage is most likely not very different from other uses though maybe a bit
higher than FFS.
rmind