2006-08-02 19:58:43

by Jeff Dike

[permalink] [raw]
Subject: [PATCH 3/4] UML - timer cleanups

set_interval returns an error instead of panicing if setitimer fails.
Some of its callers now check the return.

enable_timer is largely tt-mode-specific, so it is marked as such, and
the only skas-mode caller is made to call set-interval instead.

user_time_init was a no-value-added wrapper around set_interval, so it
is gone.

Since set_interval is now called from kernel code, callers no longer
pass ITIMER_* to it. Instead, they pass a flag which is converted
into ITIMER_REAL or ITIMER_VIRTUAL.

Signed-off-by: Jeff Dike <[email protected]>

Index: linux-2.6.18-rc2-mm1/arch/um/os-Linux/time.c
===================================================================
--- linux-2.6.18-rc2-mm1.orig/arch/um/os-Linux/time.c 2006-08-02 15:53:39.000000000 -0400
+++ linux-2.6.18-rc2-mm1/arch/um/os-Linux/time.c 2006-08-02 15:53:41.000000000 -0400
@@ -17,20 +17,25 @@
#include "kern_constants.h"
#include "os.h"

-static void set_interval(int timer_type)
+int set_interval(int is_virtual)
{
int usec = 1000000/hz();
+ int timer_type = is_virtual ? ITIMER_VIRTUAL : ITIMER_REAL;
struct itimerval interval = ((struct itimerval) { { 0, usec },
{ 0, usec } });

if(setitimer(timer_type, &interval, NULL) == -1)
- panic("setitimer failed - errno = %d\n", errno);
+ return -errno;
+
+ return 0;
}

+#ifdef CONFIG_MODE_TT
void enable_timer(void)
{
- set_interval(ITIMER_VIRTUAL);
+ set_interval(1);
}
+#endif

void disable_timer(void)
{
@@ -74,7 +79,7 @@ void uml_idle_timer(void)

set_handler(SIGALRM, (__sighandler_t) alarm_handler,
SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
- set_interval(ITIMER_REAL);
+ set_interval(0);
}
#endif

@@ -94,8 +99,3 @@ void idle_sleep(int secs)
ts.tv_nsec = 0;
nanosleep(&ts, NULL);
}
-
-void user_time_init(void)
-{
- set_interval(ITIMER_VIRTUAL);
-}
Index: linux-2.6.18-rc2-mm1/arch/um/include/os.h
===================================================================
--- linux-2.6.18-rc2-mm1.orig/arch/um/include/os.h 2006-08-02 15:53:09.000000000 -0400
+++ linux-2.6.18-rc2-mm1/arch/um/include/os.h 2006-08-02 15:53:41.000000000 -0400
@@ -276,9 +276,11 @@ extern int setjmp_wrapper(void (*proc)(v

extern void switch_timers(int to_real);
extern void idle_sleep(int secs);
+extern int set_interval(int is_virtual);
+#ifdef CONFIG_MODE_TT
extern void enable_timer(void);
+#endif
extern void disable_timer(void);
-extern void user_time_init(void);
extern void uml_idle_timer(void);
extern unsigned long long os_nsecs(void);

Index: linux-2.6.18-rc2-mm1/arch/um/os-Linux/skas/process.c
===================================================================
--- linux-2.6.18-rc2-mm1.orig/arch/um/os-Linux/skas/process.c 2006-08-02 15:53:39.000000000 -0400
+++ linux-2.6.18-rc2-mm1/arch/um/os-Linux/skas/process.c 2006-08-02 15:53:41.000000000 -0400
@@ -155,11 +155,15 @@ extern int __syscall_stub_start;
static int userspace_tramp(void *stack)
{
void *addr;
+ int err;

ptrace(PTRACE_TRACEME, 0, 0, 0);

init_new_thread_signals();
- enable_timer();
+ err = set_interval(1);
+ if(err)
+ panic("userspace_tramp - setting timer failed, errno = %d\n",
+ err);

if(!proc_mm){
/* This has a pte, but it can't be mapped in with the usual
Index: linux-2.6.18-rc2-mm1/arch/um/kernel/time.c
===================================================================
--- linux-2.6.18-rc2-mm1.orig/arch/um/kernel/time.c 2006-08-02 15:53:09.000000000 -0400
+++ linux-2.6.18-rc2-mm1/arch/um/kernel/time.c 2006-08-02 15:53:41.000000000 -0400
@@ -113,12 +113,15 @@ static void register_timer(void)

err = request_irq(TIMER_IRQ, um_timer, IRQF_DISABLED, "timer", NULL);
if(err != 0)
- printk(KERN_ERR "timer_init : request_irq failed - "
+ printk(KERN_ERR "register_timer : request_irq failed - "
"errno = %d\n", -err);

timer_irq_inited = 1;

- user_time_init();
+ err = set_interval(1);
+ if(err != 0)
+ printk(KERN_ERR "register_timer : set_interval failed - "
+ "errno = %d\n", -err);
}

extern void (*late_time_init)(void);