freebsd-nq/sys/i386/include/pcb.h
Bruce Evans b39b673d37 i386/exception.s,
Keep track of interrupt nesting level.  It is normally 0
	for syscalls and traps, but is fudged to 1 for their exit
	processing in case they metamorphose into an interrupt
	handler.

i386/genassym.c;
	Remove support for the obsolete pcb_iml and pcb_cmap2.

	Add support for pcb_inl.

i386/swtch.s:
	Fudge the interrupt nesting level across context switches and in
	the idle loop so that the work for preemptive context switches
	gets counted as interrupt time, the work for voluntary context
	switches gets counted mostly as system time (the part when
	curproc == 0 gets counted as interrupt time), and only truly idle
	time gets counted as idle time.

	Remove obsolete support (commented out and otherwise) for pcb_iml.

	Load curpcb just before curproc instead of just after so that
	curpcb is always valid if curproc is.  A few more changes like
	this may fix tracing through context switches.

	Remove obsolete function swtch_to_inactive().

include/cpu.h:
	Use the new interrupt nesting level variable to implement a
	non-fake CLF_INTR() so that accounting for the interrupt state
	works.

	You can use top, iostat or (best) an up to date systat to see
	interrupt overheads.  I see the expected huge interrupt overheads
	for ISA devices (on a 486DX/33, about 55% for an IDE drive
	transferring 1250K/sec and the same for a WD8013EBT network card
	transferring 1100K/sec).  The huge interrupt overheads for serial
	devices are unfortunately normally invisible.

include/pcb.h:
	Remove the obsolete pcb_iml and pcb_cmap2.  Replace them by
	padding to preserve binary compatibility.

	Use part of the new padding for pcb_inl.

isa/icu.s:
isa/vector.s:
	Keep track of interrupt nesting level.
1994-12-03 10:03:19 +00:00

95 lines
3.5 KiB
C

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)pcb.h 5.10 (Berkeley) 5/12/91
* $Id: pcb.h,v 1.7 1994/10/08 22:21:33 phk Exp $
*/
#ifndef _I386_PCB_H_
#define _I386_PCB_H_
/*
* Intel 386 process control block
*/
#include <machine/tss.h>
#include <machine/npx.h>
struct pcb {
struct i386tss pcb_tss;
#define pcb_ksp pcb_tss.tss_esp0
#define pcb_ptd pcb_tss.tss_cr3
#define pcb_cr3 pcb_ptd
#define pcb_pc pcb_tss.tss_eip
#define pcb_psl pcb_tss.tss_eflags
#define pcb_usp pcb_tss.tss_esp
#define pcb_fp pcb_tss.tss_ebp
#ifdef notyet
u_char pcb_iomap[NPORT/sizeof(u_char)]; /* i/o port bitmap */
#endif
caddr_t pcb_ldt; /* per process (user) LDT */
int pcb_ldt_len; /* number of LDT entries */
struct save87 pcb_savefpu; /* floating point state for 287/387 */
struct emcsts pcb_saveemc; /* Cyrix EMC state */
/*
* Software pcb (extension)
*/
int pcb_flags;
#ifdef notused
#define FP_WASUSED 0x01 /* process has used fltng pnt hardware */
#define FP_NEEDSSAVE 0x02 /* ... that needs save on next context switch */
#define FP_NEEDSRESTORE 0x04 /* ... that needs restore on next DNA fault */
#endif
#define FP_USESEMC 0x08 /* process uses EMC memory-mapped mode */
#define FP_SOFTFP 0x20 /* process using software fltng pnt emulator */
u_char pcb_inl; /* intr_nesting_level at context switch */
caddr_t pcb_onfault; /* copyin/out fault recovery */
long pcb_sigc[8]; /* XXX signal code trampoline */
int pad2; /* XXX unused - remove it if you change struct */
};
/*
* The pcb is augmented with machine-dependent additional data for
* core dumps. For the i386: ???
*/
struct md_coredump {
};
#ifdef KERNEL
extern struct pcb *curpcb; /* our current running pcb */
int savectx __P((struct pcb*,int));
#endif
#endif /* _I386_PCB_H_ */