linux/arch/um/os-Linux/time.c
Jeff Dike 5cb38bc47b [PATCH] uml: fix wall_to_monotonic initialization
From: Jeff Dike <jdike@addtoit.com>

Initialize wall_to_monotonic correctly.  This fixes a problem where sleeps
lasted about one secone less than they should.  This also called for a bit of
code restructuring, following a patch which Blaisorblade had been keeping.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-05 12:29:17 -07:00

121 lines
2.8 KiB
C

/*
* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>
#include <signal.h>
#include <errno.h>
#include "user_util.h"
#include "kern_util.h"
#include "user.h"
#include "process.h"
#include "kern_constants.h"
#include "os.h"
/* XXX This really needs to be declared and initialized in a kernel file since
* it's in <linux/time.h>
*/
extern struct timespec wall_to_monotonic;
static void set_interval(int timer_type)
{
int usec = 1000000/hz();
struct itimerval interval = ((struct itimerval) { { 0, usec },
{ 0, usec } });
if(setitimer(timer_type, &interval, NULL) == -1)
panic("setitimer failed - errno = %d\n", errno);
}
void enable_timer(void)
{
set_interval(ITIMER_VIRTUAL);
}
void disable_timer(void)
{
struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
(setitimer(ITIMER_REAL, &disable, NULL) < 0))
printk("disnable_timer - setitimer failed, errno = %d\n",
errno);
/* If there are signals already queued, after unblocking ignore them */
set_handler(SIGALRM, SIG_IGN, 0, -1);
set_handler(SIGVTALRM, SIG_IGN, 0, -1);
}
void switch_timers(int to_real)
{
struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
{ 0, 1000000/hz() }});
int old, new;
if(to_real){
old = ITIMER_VIRTUAL;
new = ITIMER_REAL;
}
else {
old = ITIMER_REAL;
new = ITIMER_VIRTUAL;
}
if((setitimer(old, &disable, NULL) < 0) ||
(setitimer(new, &enable, NULL)))
printk("switch_timers - setitimer failed, errno = %d\n",
errno);
}
void uml_idle_timer(void)
{
if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
panic("Couldn't unset SIGVTALRM handler");
set_handler(SIGALRM, (__sighandler_t) alarm_handler,
SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
set_interval(ITIMER_REAL);
}
void time_init(void)
{
if(signal(SIGVTALRM, boot_timer_handler) == SIG_ERR)
panic("Couldn't set SIGVTALRM handler");
set_interval(ITIMER_VIRTUAL);
time_init_kern();
}
unsigned long long os_nsecs(void)
{
struct timeval tv;
gettimeofday(&tv, NULL);
return((unsigned long long) tv.tv_sec * BILLION + tv.tv_usec * 1000);
}
void idle_sleep(int secs)
{
struct timespec ts;
ts.tv_sec = secs;
ts.tv_nsec = 0;
nanosleep(&ts, NULL);
}
/* XXX This partly duplicates init_irq_signals */
void user_time_init(void)
{
set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
SIGALRM, SIGUSR2, -1);
set_handler(SIGALRM, (__sighandler_t) alarm_handler,
SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
SIGVTALRM, SIGUSR2, -1);
set_interval(ITIMER_VIRTUAL);
}