Commit Graph

5 Commits

Author SHA1 Message Date
John Baldwin
5813dc03bd - Don't call clear_resched() in userret(), instead, clear the resched flag
in mi_switch() just before calling cpu_switch() so that the first switch
  after a resched request will satisfy the request.
- While I'm at it, move a few things into mi_switch() and out of
  cpu_switch(), specifically set the p_oncpu and p_lastcpu members of
  proc in mi_switch(), and handle the sched_lock state change across a
  context switch in mi_switch().
- Since cpu_switch() no longer handles the sched_lock state change, we
  have to setup an initial state for sched_lock in fork_exit() before we
  release it.
2001-02-20 05:26:15 +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
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Doug Rabson
5b38fe900d Implement 'software completion' for floating point arithmetic. On the
alpha, operations involving non-finite numbers or denormalised numbers
or operations which should generate such numbers will cause an arithmetic
exception.  For programs which follow some strict code generation rules,
the kernel trap handler can then 'complete' the operation by emulating
the faulting instruction.

To use software completion, a program must be compiled with the arguments
'-mtrap-precision=i' and '-mfp-trap-mode=su' or '-mfp-trap-mode=sui'.
Programs compiled in this way can use non-finite and denormalised numbers
at the expense of slightly less efficient code generation of floating
point instructions.  Programs not compiled with these options will receive
a SIGFPE signal when non-finite or denormalised numbers are used or
generated.

Reviewed by: John Polstra <jdp@polstra.com>
1998-12-04 10:52:48 +00:00
John Birrell
74712ec974 Import NetBSD/Alpha headers needed to get the FreeBSD userland to compile
(and even run). These files don't necessarily make sense for a
FreeBSD/Alpha kernel build. That will come later and these files
will be changed accordingly.
1998-03-09 05:43:16 +00:00