Some proc cleanup, moving some of copyproc into allocproc.
Also, an experiment: use "thread-local" storage for c and cp instead of the #define macro for curproc[cpu()].
This commit is contained in:
rsc
parent
0c7f483838
commit
19333efb9e
9 changed files with 147 additions and 118 deletions
4
Makefile
4
Makefile
|
|
@ -23,6 +23,7 @@ OBJS = \
|
|||
timer.o\
|
||||
trapasm.o\
|
||||
trap.o\
|
||||
uart.o\
|
||||
vectors.o\
|
||||
|
||||
# Cross-compiling (e.g., on Mac OS X)
|
||||
|
|
@ -139,6 +140,9 @@ bochs : fs.img xv6.img
|
|||
qemu: fs.img xv6.img
|
||||
qemu -parallel stdio -hdb fs.img xv6.img
|
||||
|
||||
qemutty: fs.img xv6.img
|
||||
qemu -nographic -smp 2 -hdb fs.img xv6.img
|
||||
|
||||
# CUT HERE
|
||||
# prepare dist for students
|
||||
# after running make dist, probably want to
|
||||
|
|
|
|||
11
defs.h
11
defs.h
|
|
@ -73,6 +73,7 @@ extern volatile uint* lapic;
|
|||
void lapiceoi(void);
|
||||
void lapicinit(int);
|
||||
void lapicstartap(uchar, uint);
|
||||
void microdelay(int);
|
||||
|
||||
// mp.c
|
||||
extern int ismp;
|
||||
|
|
@ -92,14 +93,14 @@ int pipewrite(struct pipe*, char*, int);
|
|||
|
||||
// proc.c
|
||||
struct proc* copyproc(struct proc*);
|
||||
struct proc* curproc(void);
|
||||
void exit(void);
|
||||
int growproc(int);
|
||||
int kill(int);
|
||||
void pinit(void);
|
||||
void procdump(void);
|
||||
void scheduler(void) __attribute__((noreturn));
|
||||
void setupsegs(struct proc*);
|
||||
void ksegment(void);
|
||||
void usegment(void);
|
||||
void sleep(void*, struct spinlock*);
|
||||
void userinit(void);
|
||||
int wait(void);
|
||||
|
|
@ -144,6 +145,12 @@ extern int ticks;
|
|||
void tvinit(void);
|
||||
extern struct spinlock tickslock;
|
||||
|
||||
// uart.c
|
||||
void uartinit(void);
|
||||
void uartintr(void);
|
||||
void uartputc(int);
|
||||
|
||||
|
||||
// number of elements in fixed-size array
|
||||
#define NELEM(x) (sizeof(x)/sizeof((x)[0]))
|
||||
|
||||
|
|
|
|||
2
exec.c
2
exec.c
|
|
@ -104,7 +104,7 @@ exec(char *path, char **argv)
|
|||
cp->sz = sz;
|
||||
cp->tf->eip = elf.entry; // main
|
||||
cp->tf->esp = sp;
|
||||
setupsegs(cp);
|
||||
usegment();
|
||||
return 0;
|
||||
|
||||
bad:
|
||||
|
|
|
|||
2
lapic.c
2
lapic.c
|
|
@ -121,7 +121,7 @@ lapiceoi(void)
|
|||
|
||||
// Spin for a given number of microseconds.
|
||||
// On real hardware would want to tune this dynamically.
|
||||
static void
|
||||
void
|
||||
microdelay(int us)
|
||||
{
|
||||
volatile int j = 0;
|
||||
|
|
|
|||
23
main.c
23
main.c
|
|
@ -5,6 +5,9 @@
|
|||
#include "proc.h"
|
||||
#include "x86.h"
|
||||
|
||||
__thread struct cpu *c;
|
||||
__thread struct proc *cp;
|
||||
|
||||
static void bootothers(void);
|
||||
static void mpmain(void) __attribute__((noreturn));
|
||||
|
||||
|
|
@ -14,17 +17,19 @@ main(void)
|
|||
{
|
||||
mpinit(); // collect info about this machine
|
||||
lapicinit(mpbcpu());
|
||||
cprintf("\ncpu%d: starting xv6\n\n", cpu());
|
||||
|
||||
pinit(); // process table
|
||||
binit(); // buffer cache
|
||||
ksegment();
|
||||
picinit(); // interrupt controller
|
||||
ioapicinit(); // another interrupt controller
|
||||
consoleinit(); // I/O devices & their interrupts
|
||||
uartinit(); // serial port
|
||||
cprintf("\ncpu%d: starting xv6\n\n", cpu());
|
||||
|
||||
kinit(); // physical memory allocator
|
||||
pinit(); // process table
|
||||
tvinit(); // trap vectors
|
||||
binit(); // buffer cache
|
||||
fileinit(); // file table
|
||||
iinit(); // inode cache
|
||||
consoleinit(); // I/O devices & their interrupts
|
||||
ideinit(); // disk
|
||||
if(!ismp)
|
||||
timerinit(); // uniprocessor timer
|
||||
|
|
@ -40,12 +45,12 @@ main(void)
|
|||
static void
|
||||
mpmain(void)
|
||||
{
|
||||
cprintf("cpu%d: mpmain\n", cpu());
|
||||
idtinit();
|
||||
if(cpu() != mpbcpu())
|
||||
lapicinit(cpu());
|
||||
setupsegs(0);
|
||||
xchg(&cpus[cpu()].booted, 1);
|
||||
ksegment();
|
||||
cprintf("cpu%d: mpmain\n", cpu());
|
||||
idtinit();
|
||||
xchg(&c->booted, 1);
|
||||
|
||||
cprintf("cpu%d: scheduling\n", cpu());
|
||||
scheduler();
|
||||
|
|
|
|||
148
proc.c
148
proc.c
|
|
@ -36,16 +36,31 @@ allocproc(void)
|
|||
if(p->state == UNUSED){
|
||||
p->state = EMBRYO;
|
||||
p->pid = nextpid++;
|
||||
release(&proc_table_lock);
|
||||
return p;
|
||||
goto found;
|
||||
}
|
||||
}
|
||||
release(&proc_table_lock);
|
||||
return 0;
|
||||
|
||||
found:
|
||||
release(&proc_table_lock);
|
||||
|
||||
// Allocate kernel stack if necessary.
|
||||
if((p->kstack = kalloc(KSTACKSIZE)) == 0){
|
||||
p->state = UNUSED;
|
||||
return 0;
|
||||
}
|
||||
p->tf = (struct trapframe*)(p->kstack + KSTACKSIZE) - 1;
|
||||
|
||||
// Set up new context to start executing at forkret (see below).
|
||||
p->context = (struct context *)p->tf - 1;
|
||||
memset(p->context, 0, sizeof(*p->context));
|
||||
p->context->eip = (uint)forkret;
|
||||
return p;
|
||||
}
|
||||
|
||||
// Grow current process's memory by n bytes.
|
||||
// Return old size on success, -1 on failure.
|
||||
// Return 0 on success, -1 on failure.
|
||||
int
|
||||
growproc(int n)
|
||||
{
|
||||
|
|
@ -59,37 +74,53 @@ growproc(int n)
|
|||
kfree(cp->mem, cp->sz);
|
||||
cp->mem = newmem;
|
||||
cp->sz += n;
|
||||
setupsegs(cp);
|
||||
return cp->sz - n;
|
||||
usegment();
|
||||
return 0;
|
||||
}
|
||||
|
||||
// Set up CPU's segment descriptors and task state for a given process.
|
||||
// If p==0, set up for "idle" state for when scheduler() is running.
|
||||
// Set up CPU's kernel segment descriptors.
|
||||
void
|
||||
setupsegs(struct proc *p)
|
||||
ksegment(void)
|
||||
{
|
||||
struct cpu *c;
|
||||
struct cpu *c1;
|
||||
|
||||
c1 = &cpus[cpu()];
|
||||
c1->gdt[0] = SEG_NULL;
|
||||
c1->gdt[SEG_KCODE] = SEG(STA_X|STA_R, 0, 0x100000 + 64*1024-1, 0);
|
||||
c1->gdt[SEG_KDATA] = SEG(STA_W, 0, 0xffffffff, 0);
|
||||
c1->gdt[SEG_KCPU] = SEG(STA_W, (uint)&c1->tls+sizeof(c1->tls), 0xffffffff, 0);
|
||||
c1->gdt[SEG_UCODE] = SEG_NULL;
|
||||
c1->gdt[SEG_UDATA] = SEG_NULL;
|
||||
c1->gdt[SEG_TSS] = SEG_NULL;
|
||||
lgdt(c1->gdt, sizeof(c1->gdt));
|
||||
|
||||
// Initialize cpu-local variables.
|
||||
setgs(SEG_KCPU << 3);
|
||||
c = c1;
|
||||
cp = 0;
|
||||
}
|
||||
|
||||
// Set up CPU's segment descriptors and task state for the current process.
|
||||
// If cp==0, set up for "idle" state for when scheduler() is running.
|
||||
void
|
||||
usegment(void)
|
||||
{
|
||||
pushcli();
|
||||
c = &cpus[cpu()];
|
||||
c->ts.ss0 = SEG_KDATA << 3;
|
||||
if(p)
|
||||
c->ts.esp0 = (uint)(p->kstack + KSTACKSIZE);
|
||||
if(cp)
|
||||
c->ts.esp0 = (uint)(cp->kstack + KSTACKSIZE);
|
||||
else
|
||||
c->ts.esp0 = 0xffffffff;
|
||||
|
||||
c->gdt[0] = SEG_NULL;
|
||||
c->gdt[SEG_KCODE] = SEG(STA_X|STA_R, 0, 0x100000 + 64*1024-1, 0);
|
||||
c->gdt[SEG_KDATA] = SEG(STA_W, 0, 0xffffffff, 0);
|
||||
c->gdt[SEG_TSS] = SEG16(STS_T32A, (uint)&c->ts, sizeof(c->ts)-1, 0);
|
||||
c->gdt[SEG_TSS].s = 0;
|
||||
if(p){
|
||||
c->gdt[SEG_UCODE] = SEG(STA_X|STA_R, (uint)p->mem, p->sz-1, DPL_USER);
|
||||
c->gdt[SEG_UDATA] = SEG(STA_W, (uint)p->mem, p->sz-1, DPL_USER);
|
||||
if(cp){
|
||||
c->gdt[SEG_UCODE] = SEG(STA_X|STA_R, (uint)cp->mem, cp->sz-1, DPL_USER);
|
||||
c->gdt[SEG_UDATA] = SEG(STA_W, (uint)cp->mem, cp->sz-1, DPL_USER);
|
||||
} else {
|
||||
c->gdt[SEG_UCODE] = SEG_NULL;
|
||||
c->gdt[SEG_UDATA] = SEG_NULL;
|
||||
}
|
||||
c->gdt[SEG_TSS] = SEG16(STS_T32A, (uint)&c->ts, sizeof(c->ts)-1, 0);
|
||||
c->gdt[SEG_TSS].s = 0;
|
||||
|
||||
lgdt(c->gdt, sizeof(c->gdt));
|
||||
ltr(SEG_TSS << 3);
|
||||
|
|
@ -109,40 +140,23 @@ copyproc(struct proc *p)
|
|||
if((np = allocproc()) == 0)
|
||||
return 0;
|
||||
|
||||
// Allocate kernel stack.
|
||||
if((np->kstack = kalloc(KSTACKSIZE)) == 0){
|
||||
np->state = UNUSED;
|
||||
return 0;
|
||||
}
|
||||
np->tf = (struct trapframe*)(np->kstack + KSTACKSIZE) - 1;
|
||||
|
||||
if(p){ // Copy process state from p.
|
||||
np->parent = p;
|
||||
memmove(np->tf, p->tf, sizeof(*np->tf));
|
||||
|
||||
// Copy process state from p.
|
||||
np->sz = p->sz;
|
||||
if((np->mem = kalloc(np->sz)) == 0){
|
||||
kfree(np->kstack, KSTACKSIZE);
|
||||
np->kstack = 0;
|
||||
np->state = UNUSED;
|
||||
np->parent = 0;
|
||||
return 0;
|
||||
}
|
||||
memmove(np->mem, p->mem, np->sz);
|
||||
np->parent = p;
|
||||
*np->tf = *p->tf;
|
||||
|
||||
for(i = 0; i < NOFILE; i++)
|
||||
if(p->ofile[i])
|
||||
np->ofile[i] = filedup(p->ofile[i]);
|
||||
np->cwd = idup(p->cwd);
|
||||
}
|
||||
|
||||
// Set up new context to start executing at forkret (see below).
|
||||
np->context = (struct context *)np->tf - 1;
|
||||
memset(np->context, 0, sizeof(*np->context));
|
||||
np->context->eip = (uint)forkret;
|
||||
|
||||
// Clear %eax so that fork system call returns 0 in child.
|
||||
np->tf->eax = 0;
|
||||
return np;
|
||||
}
|
||||
|
||||
|
|
@ -153,10 +167,14 @@ userinit(void)
|
|||
struct proc *p;
|
||||
extern uchar _binary_initcode_start[], _binary_initcode_size[];
|
||||
|
||||
p = copyproc(0);
|
||||
p = allocproc();
|
||||
initproc = p;
|
||||
|
||||
// Initialize memory from initcode.S
|
||||
p->sz = PAGE;
|
||||
p->mem = kalloc(p->sz);
|
||||
p->cwd = namei("/");
|
||||
memmove(p->mem, _binary_initcode_start, (int)_binary_initcode_size);
|
||||
|
||||
memset(p->tf, 0, sizeof(*p->tf));
|
||||
p->tf->cs = (SEG_UCODE << 3) | DPL_USER;
|
||||
p->tf->ds = (SEG_UDATA << 3) | DPL_USER;
|
||||
|
|
@ -164,30 +182,12 @@ userinit(void)
|
|||
p->tf->ss = p->tf->ds;
|
||||
p->tf->eflags = FL_IF;
|
||||
p->tf->esp = p->sz;
|
||||
p->tf->eip = 0; // beginning of initcode.S
|
||||
|
||||
// Make return address readable; needed for some gcc.
|
||||
p->tf->esp -= 4;
|
||||
*(uint*)(p->mem + p->tf->esp) = 0xefefefef;
|
||||
|
||||
// On entry to user space, start executing at beginning of initcode.S.
|
||||
p->tf->eip = 0;
|
||||
memmove(p->mem, _binary_initcode_start, (int)_binary_initcode_size);
|
||||
safestrcpy(p->name, "initcode", sizeof(p->name));
|
||||
p->cwd = namei("/");
|
||||
|
||||
p->state = RUNNABLE;
|
||||
|
||||
initproc = p;
|
||||
}
|
||||
|
||||
// Return currently running process.
|
||||
struct proc*
|
||||
curproc(void)
|
||||
{
|
||||
struct proc *p;
|
||||
|
||||
pushcli();
|
||||
p = cpus[cpu()].curproc;
|
||||
popcli();
|
||||
return p;
|
||||
}
|
||||
|
||||
//PAGEBREAK: 42
|
||||
|
|
@ -202,10 +202,8 @@ void
|
|||
scheduler(void)
|
||||
{
|
||||
struct proc *p;
|
||||
struct cpu *c;
|
||||
int i;
|
||||
|
||||
c = &cpus[cpu()];
|
||||
for(;;){
|
||||
// Enable interrupts on this processor, in lieu of saving intena.
|
||||
sti();
|
||||
|
|
@ -220,15 +218,15 @@ scheduler(void)
|
|||
// Switch to chosen process. It is the process's job
|
||||
// to release proc_table_lock and then reacquire it
|
||||
// before jumping back to us.
|
||||
c->curproc = p;
|
||||
setupsegs(p);
|
||||
cp = p;
|
||||
usegment();
|
||||
p->state = RUNNING;
|
||||
swtch(&c->context, &p->context);
|
||||
|
||||
// Process is done running for now.
|
||||
// It should have changed its p->state before coming back.
|
||||
c->curproc = 0;
|
||||
setupsegs(0);
|
||||
cp = 0;
|
||||
usegment();
|
||||
}
|
||||
release(&proc_table_lock);
|
||||
|
||||
|
|
@ -236,7 +234,7 @@ scheduler(void)
|
|||
}
|
||||
|
||||
// Enter scheduler. Must already hold proc_table_lock
|
||||
// and have changed curproc[cpu()]->state.
|
||||
// and have changed cp->state.
|
||||
void
|
||||
sched(void)
|
||||
{
|
||||
|
|
@ -248,12 +246,12 @@ sched(void)
|
|||
panic("sched running");
|
||||
if(!holding(&proc_table_lock))
|
||||
panic("sched proc_table_lock");
|
||||
if(cpus[cpu()].ncli != 1)
|
||||
if(c->ncli != 1)
|
||||
panic("sched locks");
|
||||
|
||||
intena = cpus[cpu()].intena;
|
||||
swtch(&cp->context, &cpus[cpu()].context);
|
||||
cpus[cpu()].intena = intena;
|
||||
intena = c->intena;
|
||||
swtch(&cp->context, &c->context);
|
||||
c->intena = intena;
|
||||
}
|
||||
|
||||
// Give up the CPU for one scheduling round.
|
||||
|
|
@ -421,6 +419,7 @@ wait(void)
|
|||
if(p->state == UNUSED)
|
||||
continue;
|
||||
if(p->parent == cp){
|
||||
havekids = 1;
|
||||
if(p->state == ZOMBIE){
|
||||
// Found one.
|
||||
kfree(p->mem, p->sz);
|
||||
|
|
@ -433,7 +432,6 @@ wait(void)
|
|||
release(&proc_table_lock);
|
||||
return pid;
|
||||
}
|
||||
havekids = 1;
|
||||
}
|
||||
}
|
||||
|
||||
|
|
|
|||
37
proc.h
37
proc.h
|
|
@ -1,17 +1,21 @@
|
|||
// Segments in proc->gdt
|
||||
// Segments in proc->gdt.
|
||||
// Also known to bootasm.S and trapasm.S
|
||||
#define SEG_KCODE 1 // kernel code
|
||||
#define SEG_KDATA 2 // kernel data+stack
|
||||
#define SEG_UCODE 3
|
||||
#define SEG_UDATA 4
|
||||
#define SEG_TSS 5 // this process's task state
|
||||
#define NSEGS 6
|
||||
#define SEG_KCPU 3 // kernel per-cpu data
|
||||
#define SEG_UCODE 4
|
||||
#define SEG_UDATA 5
|
||||
#define SEG_TSS 6 // this process's task state
|
||||
#define NSEGS 7
|
||||
|
||||
// Saved registers for kernel context switches.
|
||||
// Don't need to save all the segment registers (%cs, etc),
|
||||
// because they are constant across kernel contexts.
|
||||
// Stack pointer is encoded in the address of context,
|
||||
// which must be placed at the bottom of the stack.
|
||||
// The layout of context must match code in swtch.S.
|
||||
// Don't need to save %eax, %ecx, %edx, because the
|
||||
// x86 convention is that the caller has saved them.
|
||||
// Contexts are stored at the bottom of the stack they
|
||||
// describe; the stack pointer is the address of the context.
|
||||
// The layout of the context must match the code in swtch.S.
|
||||
struct context {
|
||||
uint edi;
|
||||
uint esi;
|
||||
|
|
@ -30,12 +34,12 @@ struct proc {
|
|||
enum proc_state state; // Process state
|
||||
int pid; // Process ID
|
||||
struct proc *parent; // Parent process
|
||||
struct trapframe *tf; // Trap frame for current syscall
|
||||
struct context *context; // Switch here to run process
|
||||
void *chan; // If non-zero, sleeping on chan
|
||||
int killed; // If non-zero, have been killed
|
||||
struct file *ofile[NOFILE]; // Open files
|
||||
struct inode *cwd; // Current directory
|
||||
struct context *context; // Switch here to run process
|
||||
struct trapframe *tf; // Trap frame for current syscall
|
||||
char name[16]; // Process name (debugging)
|
||||
};
|
||||
|
||||
|
|
@ -48,18 +52,23 @@ struct proc {
|
|||
// Per-CPU state
|
||||
struct cpu {
|
||||
uchar apicid; // Local APIC ID
|
||||
struct proc *curproc; // Process currently running.
|
||||
struct context *context; // Switch here to enter scheduler
|
||||
struct taskstate ts; // Used by x86 to find stack for interrupt
|
||||
struct segdesc gdt[NSEGS]; // x86 global descriptor table
|
||||
volatile uint booted; // Has the CPU started?
|
||||
int ncli; // Depth of pushcli nesting.
|
||||
int intena; // Were interrupts enabled before pushcli?
|
||||
void *tls[2];
|
||||
};
|
||||
|
||||
extern struct cpu cpus[NCPU];
|
||||
extern int ncpu;
|
||||
|
||||
// "cp" is a short alias for curproc().
|
||||
// It gets used enough to make this worthwhile.
|
||||
#define cp curproc()
|
||||
// Per-CPU variables, holding pointers to the
|
||||
// current cpu and to the current process.
|
||||
// The __thread prefix tells gcc to refer to them in the segment
|
||||
// pointed at by gs; the name __thread derives from the use
|
||||
// of the same mechanism to provide per-thread storage in
|
||||
// multithreaded user programs.
|
||||
extern __thread struct cpu *c; // This cpu.
|
||||
extern __thread struct proc *cp; // Current process on this cpu.
|
||||
|
|
|
|||
|
|
@ -102,8 +102,8 @@ pushcli(void)
|
|||
|
||||
eflags = readeflags();
|
||||
cli();
|
||||
if(cpus[cpu()].ncli++ == 0)
|
||||
cpus[cpu()].intena = eflags & FL_IF;
|
||||
if(c->ncli++ == 0)
|
||||
c->intena = eflags & FL_IF;
|
||||
}
|
||||
|
||||
void
|
||||
|
|
@ -111,9 +111,9 @@ popcli(void)
|
|||
{
|
||||
if(readeflags()&FL_IF)
|
||||
panic("popcli - interruptible");
|
||||
if(--cpus[cpu()].ncli < 0)
|
||||
if(--c->ncli < 0)
|
||||
panic("popcli");
|
||||
if(cpus[cpu()].ncli == 0 && cpus[cpu()].intena)
|
||||
if(c->ncli == 0 && c->intena)
|
||||
sti();
|
||||
}
|
||||
|
||||
|
|
|
|||
6
x86.h
6
x86.h
|
|
@ -103,6 +103,12 @@ xchg(volatile uint *addr, uint newval)
|
|||
return result;
|
||||
}
|
||||
|
||||
static inline void
|
||||
setgs(ushort gs)
|
||||
{
|
||||
asm volatile("movw %0, %%gs" : : "r" (gs));
|
||||
}
|
||||
|
||||
static inline void
|
||||
cli(void)
|
||||
{
|
||||
|
|
|
|||
Loading…
Reference in a new issue