critical_enter() and critical_exit() are now solely a mechanism for
deferring kernel preemptions. They no longer have any affect on
interrupts. This means that standalone critical sections are now very
cheap as they are simply unlocked integer increments and decrements for the
common case.
Spin mutexes now use a separate KPI implemented in MD code: spinlock_enter()
and spinlock_exit(). This KPI is responsible for providing whatever MD
guarantees are needed to ensure that a thread holding a spin lock won't
be preempted by any other code that will try to lock the same lock. For
now all archs continue to block interrupts in a "spinlock section" as they
did formerly in all critical sections. Note that I've also taken this
opportunity to push a few things into MD code rather than MI. For example,
critical_fork_exit() no longer exists. Instead, MD code ensures that new
threads have the correct state when they are created. Also, we no longer
try to fixup the idlethreads for APs in MI code. Instead, each arch sets
the initial curthread and adjusts the state of the idle thread it borrows
in order to perform the initial context switch.
This change is largely a big NOP, but the cleaner separation it provides
will allow for more efficient alternative locking schemes in other parts
of the kernel (bare critical sections rather than per-CPU spin mutexes
for per-CPU data for example).
Reviewed by: grehan, cognet, arch@, others
Tested on: i386, alpha, sparc64, powerpc, arm, possibly more
to see what features they may support before calling identify/probe/attach.
This is necessary because the ACPI 3.0 spec requires driver support be
advertised before running any methods. For now, the flags are as specified
in for the _PDC and _OSC methods but we can support private flags as needed.
Add an implementation of this for acpi_cpu. It checks all its children
(notably cpufreq drivers) and calls the _PDC method to report the results.
instances in a given devclass. This is useful for systems that want to
call code in driver static methods, similar to device_identify().
Reviewed by: dfr
MFC after: 2 weeks
one to become available for one second and then return ENFILE. We
can run out of vnodes, and there must be a hard limit because without
one we can quickly run out of KVA on x86. Presently the system can
deadlock if there are maxvnodes directories in the namecache. The
original 4.x BSD behavior was to return ENFILE if we reached the max,
but 4.x BSD did not have the vnlru proc so it was less profitable to
wait.
down. If we have dirty pages, the putpages routine will need to know
what the vnode's object is so that it may write out dirty pages.
Pointy hat: phk
Found by: obrien
in a devclass. All the other uses of maxunit are correct and this one was
safe since it checks the return value of devclass_get_device(), which would
always say that the highest unit device doesn't exist.
Reviewed by: dfr
MFC after: 3 days
completed I/O requests here.
- First allocate all needed bios, so if any of allocations fail, we can
free memory before sending any I/O requests down.
Reported by: Pawel Malachowski
MFC after: 3 days
- Don't intermingle direct calls to lockmgr and indirect calls through
VOPs. This will be important in the future.
- Dont lock the devvp's interlock just to release it on the next line by
passing LK_INTERLOCK to lockmgr.
- Restructure ffs_snapshot_unmount so we don't call free() with the
devvp's interlock locked.
because it may change identities while we're sleeping on the lock.
Otherwise we may bail out of ffs_sync() early due to an error from
deadfs.
- Collapse a VOP_UNLOCK, vrele into a single vput().
two bugs.
- ffs_disk_prewrite was pulling the vp from the buf and checking for
COPYONWRITE, when really it wanted the vp from the bufobj that we're
writing to, which is the devvp. This lead to us skipping the copy on
write to all file data, which significantly broke snapshots for the
last few months.
- When the SOFTUPDATES option was not included in the kernel config we
would also skip the copy on write check, which would effectively disable
snapshots.
- Remove an invalid mp_fixme().
Debugging tips from: mckusick
Reported by: iedowse, others
Discussed with: phk
generate dirty bufs even with a locked vnode, 100 retries is not that
many. This should probably change from a retry count to an abort when
we are no longer cleaning any buffers.
- Don't call vprint() while we still hold the vnode locked. Move the call
to later in the function.
- Clean up a comment.
implementations inspired by the ones in DragonFly. Unlike the
DragonFly versions, these have a small data cache footprint, and my
tests show that they're never slower than the old code except when the
charset or the span is 0 or 1 characters. This implementation is
generally faster than DragonFly until either the charset or the span
gets in the ballpark of 32 to 64 characters.
compiler features tests. This is ok, since machine/ieeefp.h is an internal
interface. But floatingpoint.h is a public interface and some ports use it,
so include sys/cdefs.h in the amd64 and i386 version of floatingpoint.h.
Note: some architectures don't provide recursive inclusion protection in
floatingpoint.h, namely alpha and ia64. Except for this part and now the
include of sys/cdefs.h, all those files are equal (from a compiler POV),
so they could be moved to only one version in src/include/.
Approved by: joerg
these at the moment, but applications that test for them will now
have a better chance of compiling.
I have intentionally omitted errnos that are only good for STREAMS,
since apps that use STREAMS won't compile anyway. The exception is
EPROTO, which was apparently intended for STREAMS, but worth having
anyway because Linux (mis)uses it for other things.
specific code will migrate to these files to augment or replace the
version in i386/include and/or i386/linux. This should, in the
fullness of time, allow many of the #ifdef PC98 in the tree.
# These files are in the public domain because there is insufficient
# creative content in them. When you customize them, please add a
# copyright notice and license.
OK'd in principle by: nyan@
creating the /dev/dpti%d entry that the software expects. This is just
a band-aid until either someone (hopefully) rewrites the utilities, or all
asr/dpt cards in existance get blasted into the sun.
the type of object represented by the handle argument.
- Allow vm_mmap() to map device memory via cdev objects in addition to
vnodes and anonymous memory. Note that mmaping a cdev directly does not
currently perform any MAC checks like mapping a vnode does.
- Unbreak the DRM getbufs ioctl by having it call vm_mmap() directly on the
cdev the ioctl is acting on rather than trying to find a suitable vnode
to map from.
Reviewed by: alc, arch@
