Commit Graph

17 Commits

Author SHA1 Message Date
Jake Burkholder
03cd4c2029 Implement optimized PCPU accessors. These are necessary to support a
pre-emptable kernel.  For variables of size 4 bytes or less they compile
to a single instruction, which does not allow a process to migrate cpus
in the middle, and get the value for the "wrong" cpu.
2001-01-21 03:11:03 +00:00
Jake Burkholder
df729d6f00 - Remove compatibility macros for accessing per-cpu variables.
__FreeBSD_version 500015 can be used to detect their disappearance.
- Move the symbols for SMP_prvspace and lapic from globals.s to
  locore.s.
- Remove globals.s with extreme prejudice.
2001-01-11 14:46:26 +00:00
Jake Burkholder
f8761e53a7 Implement accessors for per-cpu variables which don't depend on the
symbols in globals.s.

	PCPU_GET(name) returns the value of the per-cpu variable
	PCPU_PTR(name) returns a pointer to the per-cpu variable
	PCPU_SET(name, val) sets the value of the per-cpu variable

In general these are not yet used, compatibility macros remain.

Unifdef SMP struct globaldata, this makes variables such as cpuid
available for UP as well.

Rebuilding modules is probably a good idea, but I believe old
modules will still work, as most of the old infrastructure
remains.
2001-01-06 19:55:42 +00:00
Jake Burkholder
41ed17bfec Use %fs to access per-cpu variables in uni-processor kernels the same
as multi-processor kernels.  The old way made it difficult for kernel
modules to be portable between uni-processor and multi-processor
kernels.  It is no longer necessary to jump through hoops.

- always load %fs with the private segment on entry to the kernel
- change the type of the self referntial pointer from struct privatespace
  to struct globaldata
- make the globaldata symbol have value 0 in all cases, so the symbols
  in globals.s are always offsets, not aliases for fields in globaldata
- define the globaldata space used for uniprocessor kernels in C, rather
  than assembler
- change the assmebly language accessors to use %fs, add a macro
  PCPU_ADDR(member, reg), which loads the register reg with the address
  of the per-cpu variable member
2001-01-06 17:40:04 +00:00
John Baldwin
59f857e4ea Declare the 'witness_spin_check' properly as a per-CPU variable in the
non-SMP case.
2000-11-15 22:02:05 +00:00
Bruce Evans
4a3bb59944 Declare or #define per-cpu globals in <machine/globals.h> in all cases.
The i386 UP case was messily different.
2000-10-27 08:30:59 +00:00
Matt Jacob
eb661345a9 Move bogus proc reference stuff into <machine/globals.h>. There is no
more include file including <sys/proc.h>, but there still is this wonky
and (causes warnings on i386) reference in globals.h.

CURTHD is now defined in <machine/globals.h> as well. The correct thing
to do is provide a platform function for this.
2000-10-23 18:36:03 +00:00
Poul-Henning Kamp
416282b562 Get rid of the last traces of ACTUALLY_LKM_NOT_KERNEL 2000-10-23 08:35:41 +00:00
Bruce Evans
1676212c30 Moved the declaration of astpending to the correct place.
This shouldn't affect the alpha or ia64, since they don't have a
variable named astpending.  The alpha still has 2 declarations of
this nonexistent variable.
2000-10-12 13:02:13 +00:00
John Baldwin
6c56727456 - Change fast interrupts on x86 to push a full interrupt frame and to
return through doreti to handle ast's.  This is necessary for the
  clock interrupts to work properly.
- Change the clock interrupts on the x86 to be fast instead of threaded.
  This is needed because both hardclock() and statclock() need to run in
  the context of the current process, not in a separate thread context.
- Kill the prevproc hack as it is no longer needed.
- We really need Giant when we call psignal(), but we don't want to block
  during the clock interrupt.  Instead, use two p_flag's in the proc struct
  to mark the current process as having a pending SIGVTALRM or a SIGPROF
  and let them be delivered during ast() when hardclock() has finished
  running.
- Remove CLKF_BASEPRI, which was #ifdef'd out on the x86 anyways.  It was
  broken on the x86 if it was turned on since cpl is gone.  It's only use
  was to bogusly run softclock() directly during hardclock() rather than
  scheduling an SWI.
- Remove the COM_LOCK simplelock and replace it with a clock_lock spin
  mutex.  Since the spin mutex already handles disabling/restoring
  interrupts appropriately, this also lets us axe all the *_intr() fu.
- Back out the hacks in the APIC_IO x86 cpu_initclocks() code to use
  temporary fast interrupts for the APIC trial.
- Add two new process flags P_ALRMPEND and P_PROFPEND to mark the pending
  signals in hardclock() that are to be delivered in ast().

Submitted by:	jakeb (making statclock safe in a fast interrupt)
Submitted by:	cp (concept of delaying signals until ast())
2000-10-06 02:20:21 +00:00
Jason Evans
0384fff8c5 Major update to the way synchronization is done in the kernel. Highlights
include:

* Mutual exclusion is used instead of spl*().  See mutex(9).  (Note: The
  alpha port is still in transition and currently uses both.)

* Per-CPU idle processes.

* Interrupts are run in their own separate kernel threads and can be
  preempted (i386 only).

Partially contributed by:	BSDi (BSD/OS)
Submissions by (at least):	cp, dfr, dillon, grog, jake, jhb, sheldonh
2000-09-07 01:33:02 +00:00
Matthew Dillon
36e9f877df Commit major SMP cleanups and move the BGL (big giant lock) in the
syscall path inward.  A system call may select whether it needs the MP
    lock or not (the default being that it does need it).

    A great deal of conditional SMP code for various deadended experiments
    has been removed.  'cil' and 'cml' have been removed entirely, and the
    locking around the cpl has been removed.  The conditional
    separately-locked fast-interrupt code has been removed, meaning that
    interrupts must hold the CPL now (but they pretty much had to anyway).
    Another reason for doing this is that the original separate-lock for
    interrupts just doesn't apply to the interrupt thread mechanism being
    contemplated.

    Modifications to the cpl may now ONLY occur while holding the MP
    lock.  For example, if an otherwise MP safe syscall needs to mess with
    the cpl, it must hold the MP lock for the duration and must (as usual)
    save/restore the cpl in a nested fashion.

    This is precursor work for the real meat coming later: avoiding having
    to hold the MP lock for common syscalls and I/O's and interrupt threads.
    It is expected that the spl mechanisms and new interrupt threading
    mechanisms will be able to run in tandem, allowing a slow piecemeal
    transition to occur.

    This patch should result in a moderate performance improvement due to
    the considerable amount of code that has been removed from the critical
    path, especially the simplification of the spl*() calls.  The real
    performance gains will come later.

Approved by: jkh
Reviewed by: current, bde (exception.s)
Some work taken from: luoqi's patch
2000-03-28 07:16:37 +00:00
Peter Wemm
664a31e496 Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot).  This is consistant with the other
BSD's who made this change quite some time ago.  More commits to come.
1999-12-29 04:46:21 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Jonathan Lemon
eb9d435ae7 Unifdef VM86.
Reviewed by:	silence on on -current
1999-06-01 18:20:36 +00:00
Luoqi Chen
0f0fe5a4c5 Unbreak VESA on SMP. 1999-05-12 21:39:07 +00:00
Luoqi Chen
5206bca10a Enable vmspace sharing on SMP. Major changes are,
- %fs register is added to trapframe and saved/restored upon kernel entry/exit.
- Per-cpu pages are no longer mapped at the same virtual address.
- Each cpu now has a separate gdt selector table. A new segment selector
  is added to point to per-cpu pages, per-cpu global variables are now
  accessed through this new selector (%fs). The selectors in gdt table are
  rearranged for cache line optimization.
- fask_vfork is now on as default for both UP and SMP.
- Some aio code cleanup.

Reviewed by:	Alan Cox	<alc@cs.rice.edu>
		John Dyson	<dyson@iquest.net>
		Julian Elischer	<julian@whistel.com>
		Bruce Evans	<bde@zeta.org.au>
		David Greenman	<dg@root.com>
1999-04-28 01:04:33 +00:00