b39b673d37
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.
138 lines
4.7 KiB
C
138 lines
4.7 KiB
C
/*-
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* William Jolitz.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)cpu.h 5.4 (Berkeley) 5/9/91
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* $Id: cpu.h,v 1.17 1994/11/26 09:27:58 phk Exp $
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*/
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#ifndef _MACHINE_CPU_H_
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#define _MACHINE_CPU_H_
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/*
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* Definitions unique to i386 cpu support.
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*/
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#include <machine/frame.h>
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#include <machine/segments.h>
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/*
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* definitions of cpu-dependent requirements
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* referenced in generic code
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*/
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#undef COPY_SIGCODE /* don't copy sigcode above user stack in exec */
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#define cpu_exec(p) /* nothing */
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#define cpu_swapin(p) /* nothing */
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#define cpu_setstack(p, ap) (p)->p_md.md_regs = ap
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#define cpu_set_init_frame(p, fp) (p)->p_md.md_regs = fp
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#define CLKF_USERMODE(framep) (ISPL((framep)->cf_cs) == SEL_UPL)
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#define CLKF_INTR(framep) (intr_nesting_level >= 2)
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#if 1
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/*
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* XXX splsoftclock() is very broken and barely worth fixing. It doesn't
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* turn off the clock bit in imen or in the icu. (This is not a serious
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* problem at 100 Hz but it is serious at 16000 Hz for pcaudio. softclock()
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* can take more than 62.5 usec so clock interrupts are lost.) It doesn't
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* check for pending interrupts being unmasked. clkintr() and Xintr0()
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* assume that the ipl is high when hardclock() returns. Our SWI_AST
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* handling is efficient enough that little is gained by calling
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* softclock() directly.
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*/
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#define CLKF_BASEPRI(framep) (((framep)->cf_ppl & ~SWI_AST_MASK) == 0)
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#else
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#define CLKF_BASEPRI(framep) (0)
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#endif
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#define CLKF_PC(framep) ((framep)->cf_eip)
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/*
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* Preempt the current process if in interrupt from user mode,
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* or after the current trap/syscall if in system mode.
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*/
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#define need_resched() { want_resched = 1; aston(); }
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/*
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* Give a profiling tick to the current process from the softclock
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* interrupt. On tahoe, request an ast to send us through trap(),
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* marking the proc as needing a profiling tick.
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*/
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#define need_proftick(p) { (p)->p_flag |= P_OWEUPC; aston(); }
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/*
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* Notify the current process (p) that it has a signal pending,
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* process as soon as possible.
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*/
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#define signotify(p) aston()
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#define aston() setsoftast()
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#define astoff()
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/*
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* pull in #defines for kinds of processors
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*/
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#include <machine/cputypes.h>
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struct cpu_nameclass {
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char *cpu_name;
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int cpu_class;
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};
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/*
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* CTL_MACHDEP definitions.
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*/
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#define CPU_CONSDEV 1 /* dev_t: console terminal device */
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#define CPU_ADJKERNTZ 2 /* int: timezone offset for resettodr() */
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#define CPU_DISRTCSET 3 /* int: disable resettodr() call */
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#define CPU_MAXID 4 /* number of valid machdep ids */
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#define CTL_MACHDEP_NAMES { \
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{ 0, 0 }, \
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{ "console_device", CTLTYPE_STRUCT }, \
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{ "adjkerntz", CTLTYPE_INT }, \
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{ "disable_rtc_set", CTLTYPE_INT }, \
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}
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#ifdef KERNEL
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extern int bootverbose;
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extern int cpu;
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extern int cpu_class;
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extern u_char intr_nesting_level;
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extern struct cpu_nameclass i386_cpus[];
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extern int want_resched; /* resched was called */
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int cpu_fork __P((struct proc *, struct proc *));
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#endif
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#endif /* !_MACHINE_CPU_H_ */
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