IPI_STOP IPIs.
- Change the i386 and amd64 MD IPI code to send an NMI if STOP_NMI is
enabled if an attempt is made to send an IPI_STOP IPI. If the kernel
option is enabled, there is also a sysctl to change the behavior at
runtime (debug.stop_cpus_with_nmi which defaults to enabled). This
includes removing stop_cpus_nmi() and making ipi_nmi_selected() a
private function for i386 and amd64.
- Fix ipi_all(), ipi_all_but_self(), and ipi_self() on i386 and amd64 to
properly handle bitmapped IPIs as well as IPI_STOP IPIs when STOP_NMI is
enabled.
- Fix ipi_nmi_handler() to execute the restart function on the first CPU
that is restarted making use of atomic_readandclear() rather than
assuming that the BSP is always included in the set of restarted CPUs.
Also, the NMI handler didn't clear the function pointer meaning that
subsequent stop and restarts could execute the function again.
- Define a new macro HAVE_STOPPEDPCBS on i386 and amd64 to control the use
of stoppedpcbs[] and always enable it for i386 and amd64 instead of
being dependent on KDB_STOP_NMI. It works fine in both the NMI and
non-NMI cases.
as they are already default for I686_CPU for almost 3 years, and
CPU_DISABLE_SSE always disables it. On the other hand, CPU_ENABLE_SSE
does not work for I486_CPU and I586_CPU.
This commit has:
- Removed the option from conf/options.*
- Removed the option and comments from MD NOTES files
- Simplified the CPU_ENABLE_SSE ifdef's so they don't
deal with CPU_ENABLE_SSE from kernel configuration. (*)
For most users, this commit should be largely no-op. If you used to
place CPU_ENABLE_SSE into your kernel configuration for some reason,
it is time to remove it.
(*) The ifdef's of CPU_ENABLE_SSE are not removed at this point, since
we need to change it to !defined(CPU_DISABLE_SSE) && defined(I686_CPU),
not just !defined(CPU_DISABLE_SSE), if we really want to do so.
Discussed on: -arch
Approved by: re (scottl)
remaining consumers to have the count passed as an option. This is
i4b, pc98/wdc, and coda.
Bump configvers.h from 500013 to 600000.
Remove heuristics that tried to parse "device ed5" as 5 units of the ed
device. This broke things like the snd_emu10k1 device, which required
quotes to make it parse right. The no-longer-needed quotes have been
removed from NOTES, GENERIC etc. eg, I've removed the quotes from:
device snd_maestro
device "snd_maestro3"
device snd_mss
I believe everything will still compile and work after this.
amd64 agp option here in order to let the pc98 kernel build
complete. This doesn't seem right, since there probably aren't
plans to build a pc98 amd64 box; however, it's not clear to me
how to get config to generate an opt_agp.h without an option
defined.
Only cy, bs and wd in the tree still use it. I have a replacement for
cy that I need to test on ISA and PCI cards. bs and wd are pc98 only
drivers that appear to no longer be necessary. I'll be removing them
when I hear back from the pc98 people.
should only be used if they are enabled in the BIOS. Now that we support
enumerating CPUs using the ACPI MADT, any HTT machine using ACPI should
respect the BIOS setting. For HTT machines with ACPI disabled in the
kernel, the MPTABLE_FORCE_HTT kernel option can be used to try to probe HTT
CPUs like have done in the past for the MP Table case. This option should
only be enabled if HTT is enabled in the BIOS.
This keeps the logical cpu's halted in the idle loop. By default
the logical cpu's are halted at startup. It is also possible to
halt any cpu in the idle loop now using machdep.hlt_cpus.
Examples of how to use this:
machdep.hlt_cpus=1 halt cpu0
machdep.hlt_cpus=2 halt cpu1
machdep.hlt_cpus=4 halt cpu2
machdep.hlt_cpus=3 halt cpu0,cpu1
Reviewed by: jhb, peter
support this, we do have MI code that references it and is otherwise
unaware of an override. The alternative is to put knowledge in these
MI files about which platforms have the opt_kstack_pages.h option file.
It is more likely that other platforms will gain the ability to tune the
kstack size.
if compiling with I686_CPU as a target. CPU_DISABLE_SSE will prevent
this from happening and will guarantee the code is not compiled in.
I am still not happy with this, but gcc is now generating code that uses
these instructions if you set CPUTYPE to p3/p4 or athlon-4/mp/xp or higher.
- It actually works this time, honest!
- Fine grained TLB shootdowns for SMP on i386. IPI's are very expensive,
so try and optimize things where possible.
- Introduce ranged shootdowns that can be done as a single IPI.
- PG_G support for i386
- Specific-cpu targeted shootdowns. For example, there is no sense in
globally purging the TLB cache for where we are stealing a page from
the local unshared process on the local cpu. Use pm_active to track
this.
- Add some instrumentation for the tlb shootdown code.
- Rip out SMP code from <machine/cpufunc.h>
- Try and fix some very bogus PG_G and PG_PS interactions that were bad
enough to cause vm86 bios calls to break. vm86 depended on our existing
bugs and this was the cause of the VESA panics last time.
- Fix the silly one-line error that caused the 'panic: bad pte' last time.
- Fix a couple of other silly one-line errors that should have caused more
pain than they did.
Some more work is needed:
- pmap_{zero,copy}_page[_idle]. These can be done without IPI's if we
have a hook in cpu_switch.
- The IPI handlers need some cleanup. I have a bogus %ds load that can
be avoided.
- APTD handling is rather bogus and appears to be a large source of
global TLB IPI shootdowns for no really good reason.
I see speedups of between 1.5% and ~4% on buildworlds in a while 1 loop.
I expect to see a bigger difference when there is significant pageout
activity or the system otherwise has memory shortages.
I have backed out a few optimizations that I had been using over the last
few days in order to be a little more conservative. I'll revisit these
again over the next few days as the dust settles.
New option: DISABLE_PG_G - In case I missed something.
This facilitates the use in circumstances where you are using a serial
console as well. GDB doesn't support anything higher than 9600 baud (19k2
if you are lucky), but the console does.
There is some unresolved badness that has been eluding me, particularly
affecting uniprocessor kernels. Turning off PG_G helped (which is a bad
sign) but didn't solve it entirely. Userland programs still crashed.
on for a while:
- fine grained TLB shootdown for SMP on i386
- ranged TLB shootdowns.. eg: specify a range of pages to shoot down with
a single IPI, since the IPI is very expensive. Adjust some callers
that used to trigger this inside tight loops to do a ranged shootdown
at the end instead.
- PG_G support for SMP on i386 (options ENABLE_PG_G)
- defer PG_G activation till after we decide what we are going to do with
PSE and the 4MB pages at the start of the kernel. This should solve
some rumored strangeness about stale PG_G entries getting stuck
underneath the 4MB pages.
- add some instrumentation for the fine TLB shootdown
- convert some asm instruction wrappers from functions to inlines. gcc
seems to do a fair bit better with this.
- [temporarily!] pessimize the tlb shootdown IPI handlers. I will fix
this again shortly.
This has been working fairly well for me for a while, but I have tweaked
it again prior to commit since my last major testing round. The only
outstanding problem that I know of is PG_G related, which is why there
is an option for it (not on by default for SMP). I have seen a world
speedups by a few percent (as much as 4 or 5% in one case) but I have
*not* accurately measured this - I am a bit sceptical of these numbers.
