can do 64 bytes at a time and don't allocate lines in the L2 cache. These
assume that everything is 64 byte aligned, and that there's more than 128
bytes of data (best for whole pages). The block load and store instructions
don't follow normal memory ordering rules and require either a memory barrier
or move between registers before the data can actually be used. This
implementation correctly shuffles around 3 out of the 4 sets of registers
in order to avoid memory barriers expect for the last 2 blocks.
will be saved if we context switch as a result of an interrupt which occured
while using the floating point registers in the kernel (which actually can't
happen right now). This allows fp disabled traps in the kernel, which
normally shouldn't happen, so make sure the trapping code is what we expect
it is.
used to support block copy and zero operations in the kernel which use the
floating point registers.
- While I'm changing the size, improve the layout of struct pcb, sort by size,
then alphabetical etc.
- Add some assertions to validate assumptions made about how the pcb is
allocated.
for temporaries relating to the state of the new process instead of the
outs, so that functions can be called without fear of clobbering them.
- Use savefpctx instead of rolling our own.
- Treat each class specially in kseq_{choose,add,rem}. Let the rest of the
code be less aware of scheduling classes.
- Skip the interactivity calculation for non TIMESHARE ksegrps.
- Move slice and runq selection into kseq_add(). Uninline it now that it's
big.
as it could be and can do with some more cleanup. Currently its under
options LAZY_SWITCH. What this does is avoid %cr3 reloads for short
context switches that do not involve another user process. ie: we can
take an interrupt, switch to a kthread and return to the user without
explicitly flushing the tlb. However, this isn't as exciting as it could
be, the interrupt overhead is still high and too much blocks on Giant
still. There are some debug sysctls, for stats and for an on/off switch.
The main problem with doing this has been "what if the process that you're
running on exits while we're borrowing its address space?" - in this case
we use an IPI to give it a kick when we're about to reclaim the pmap.
Its not compiled in unless you add the LAZY_SWITCH option. I want to fix a
few more things and get some more feedback before turning it on by default.
This is NOT a replacement for Bosko's lazy interrupt stuff. This was more
meant for the kthread case, while his was for interrupts. Mine helps a
little for interrupts, but his helps a lot more.
The stats are enabled with options SWTCH_OPTIM_STATS - this has been a
pseudo-option for years, I just added a bunch of stuff to it.
One non-trivial change was to select a new thread before calling
cpu_switch() in the first place. This allows us to catch the silly
case of doing a cpu_switch() to the current process. This happens
uncomfortably often. This simplifies a bit of the asm code in cpu_switch
(no longer have to call choosethread() in the middle). This has been
implemented on i386 and (thanks to jake) sparc64. The others will come
soon. This is actually seperate to the lazy switch stuff.
Glanced at by: jake, jhb
event posting functions varargs to fill these.
Attribute g_call_me() to appropriate g_geom's where necessary.
Add a flag argument to g_call_me() methods which will be used to signal
cancellation of events in the future.
This commit should be a no-op.
This patch is rather big because I had to significantly redesign
the driver to make the busdma conversion possible. Most notably,
hardware and software structures were carefully splitted to get
rid of all the structs overlapping evilness.
Special thanks to phk and Richard Puga <puga@mauibuilt.com> for
providing me with fxp(4) hardware to do this work.
Thanks to marcel for testing this on ia64, and to Fred Clift
<fclift@verio.net> for testing this on alpha.
Tested on: i386, ia64, alpha
KASSERT the race between close and strategy, it is an error in the upper
echelons if this happens,
Add XXX: comment explaining why the ioctl/orphan race is not closed.
to select a KSE with a slice of 0 we will update its slice and insert it
onto the next queue.
- Pass the KSE instead of the ksegrp into sched_slice(). This more
accurately reflects the behavior of the code. Slices are granted to kses.
- Add a function kseq_nice_min() which finds the smallest nice value
assigned to the kseg of any KSE on the queue.
- Rewrite the logic in sched_slice(). Add a large comment describing the
new slice selection scheme. To summarize, slices are assigned based on
the nice value. Priorities are still calculated based on the nice and
interactivity of a process. Slice sizes of 0 may be granted for KSEs
whos nice is 20 or futher away from the lowest nice on the run queue.
Other nice values are scaled across the range [min, min+20]. This fixes
ULEs bad behavior with positively niced processes.
set_mcontext.
- Don't make assumptions about the alignment of the mcontext inside of the
ucontext; we have to save the floating point registers to the pcb and then
copy to the mcontext.
doing Limited Transmit. Only artificially inflate the congestion
window by 1 segment instead of the usual 3 to take into account
the 2 already sent by Limited Transmit.
Approved in principle by: Mark Allman <mallman@grc.nasa.gov>,
Hari Balakrishnan <hari@nms.lcs.mit.edu>, Sally Floyd <floyd@icir.org>
