run queue for each cpu.
- Introduce kse stealing into the sched_choose() code. This helps balance
cpus better in cases where process turnover is high. This implementation
is fairly trivial and will likely be only a temporary measure until
something more sophisticated has been written.
kind of pseudofs-based filesystem. Fixes (at least) one problem where
when procfs is mounted mupltiple times, trying to unmount one will often
cause the wrong one to get unmounted, and other problem where mounting
one procfs on top of another caused the kernel to lock up.
Reviewed by: des
- Honor the previous behavior of maxfragpackets = 0 or -1
- Take a better stab at fragment statistics
- Move / correct a comment
Suggested by: maxim@
MFC after: 7 days
the sabtty device to create its description so that they will be
unique for machines with multiple sab chips.
This fixes a panic on machines with an rsc card.
Tested by: obrien (e250)
Properly handle the newer Promise SuperSwap 1000 enclosures.
Print out what kind of enclosure was found in the probe.
Misc cleanups in the enclosure handling code.
Sponsored by: Advanis Inc.
devices.
We use the md_pad[] array and if there are more units than its size the
last returned unit number will be -1, but the number of units returned
is correct.
name of the device that it creates. Update /etc/ttys accordingly.
An alias is created for the old name so that old /etc/ttys will continue to
work, but due to aliases being implemented as symlinks in devfs you cannot
login as root when using the alias device.
Discussed with: grehan
labeled disk.
This is complicated by the fact that BBSIZE is greater than the
PAGE_SIZE limit ioctl inflicts on arguments which are automatically
copied in.
As long as we don't need access to userland memory (copyin/out) we
can deal with the ioctl using g_callme() which executes it from the
GEOM event thread.
Once we need copyin/out, we need to return the bio with EDIRIOCTL
in order to make geom_dev call us back in the original process context
where copyin will work.
Unfortunately, that results in us getting called with Giant, so
we have to DROP_GIANT/PICKUP_GIANT around the code where we diddle
GEOMs internals.
Sometimes you just can't win...
... But it does make geom_bsd.c an almost complete example of the
GEOM beastiarium.
data structure called kse_upcall to manage UPCALL. All KSE binding
and loaning code are gone.
A thread owns an upcall can collect all completed syscall contexts in
its ksegrp, turn itself into UPCALL mode, and takes those contexts back
to userland. Any thread without upcall structure has to export their
contexts and exit at user boundary.
Any thread running in user mode owns an upcall structure, when it enters
kernel, if the kse mailbox's current thread pointer is not NULL, then
when the thread is blocked in kernel, a new UPCALL thread is created and
the upcall structure is transfered to the new UPCALL thread. if the kse
mailbox's current thread pointer is NULL, then when a thread is blocked
in kernel, no UPCALL thread will be created.
Each upcall always has an owner thread. Userland can remove an upcall by
calling kse_exit, when all upcalls in ksegrp are removed, the group is
atomatically shutdown. An upcall owner thread also exits when process is
in exiting state. when an owner thread exits, the upcall it owns is also
removed.
KSE is a pure scheduler entity. it represents a virtual cpu. when a thread
is running, it always has a KSE associated with it. scheduler is free to
assign a KSE to thread according thread priority, if thread priority is changed,
KSE can be moved from one thread to another.
When a ksegrp is created, there is always N KSEs created in the group. the
N is the number of physical cpu in the current system. This makes it is
possible that even an userland UTS is single CPU safe, threads in kernel still
can execute on different cpu in parallel. Userland calls kse_create to add more
upcall structures into ksegrp to increase concurrent in userland itself, kernel
is not restricted by number of upcalls userland provides.
The code hasn't been tested under SMP by author due to lack of hardware.
Reviewed by: julian
