Re: [PATCH 4/7] posix-timers: CPU clock support for POSIX timers
From: George Anzinger
Date: Tue Jan 25 2005 - 18:49:38 EST
Christoph Lameter wrote:
On Mon, 24 Jan 2005, Christoph Lameter wrote:
It would be great to have a kind of private field that other clocks (like
clock drivers) could use for their purposes. mmtimer f.e. does use some
of the fields for the tick based timers for its purposes.
On that note:
Your patch breaks the mmtimer driver because it used k_itimer values for
its own purposes. Here is a fix by defining an additional structure
in k_itimer (same approach for mmtimer as the cpu timers):
I would like to get a read on the following defines...
#define mmclock mmtimer.clock
#define mmnode mmtimer.node
#define mmincr mmtimer.incr
#define mmexpires mmtimer.expires
Then, of course, you would use the defines instead of the "." references. Is
this a big no-no in kernel code. Seems to me it makes things a bit easier to read.
George
Signed-off-by: Christoph Lameter <clameter@xxxxxxx>
Index: linux-2.6.10/include/linux/posix-timers.h
===================================================================
--- linux-2.6.10.orig/include/linux/posix-timers.h 2005-01-25 14:35:11.000000000 -0800
+++ linux-2.6.10/include/linux/posix-timers.h 2005-01-25 14:35:16.000000000 -0800
@@ -57,6 +57,12 @@ struct k_itimer {
unsigned long incr; /* interval in jiffies */
} real;
struct cpu_timer_list cpu;
+ struct {
+ unsigned int clock;
+ unsigned int node;
+ unsigned long incr;
+ unsigned long expires;
+ } mmtimer;
} it;
};
#define mmclock mmtimer.clock
#define mmnode mmtimer.node
#define mmincr mmtimer.incr
#define mmexpires mmtimer.expires
Index: linux-2.6.10/drivers/char/mmtimer.c
===================================================================
--- linux-2.6.10.orig/drivers/char/mmtimer.c 2005-01-25 14:35:09.000000000 -0800
+++ linux-2.6.10/drivers/char/mmtimer.c 2005-01-25 14:34:41.000000000 -0800
@@ -420,19 +420,19 @@ static int inline reschedule_periodic_ti
int n;
struct k_itimer *t = x->timer;
- t->it_timer.magic = x->i;
+ t->it.mmtimer.clock = x->i;
t->it_overrun--;
n = 0;
do {
- t->it_timer.expires += t->it_incr << n;
+ t->it.mmtimer.expires += t->it.mmtimer.incr << n;
t->it_overrun += 1 << n;
n++;
if (n > 20)
return 1;
- } while (mmtimer_setup(x->i, t->it_timer.expires));
+ } while (mmtimer_setup(x->i, t->it.mmtimer.expires));
return 0;
}
@@ -468,7 +468,7 @@ mmtimer_interrupt(int irq, void *dev_id,
spin_lock(&base[i].lock);
if (base[i].cpu == smp_processor_id()) {
if (base[i].timer)
- expires = base[i].timer->it_timer.expires;
+ expires = base[i].timer->it.mmtimer.expires;
/* expires test won't work with shared irqs */
if ((mmtimer_int_pending(i) > 0) ||
(expires && (expires < rtc_time()))) {
@@ -505,7 +505,7 @@ void mmtimer_tasklet(unsigned long data)
t->it_overrun++;
}
- if(t->it_incr) {
+ if(t->it.mmtimer.incr) {
/* Periodic timer */
if (reschedule_periodic_timer(x)) {
printk(KERN_WARNING "mmtimer: unable to reschedule\n");
@@ -513,7 +513,7 @@ void mmtimer_tasklet(unsigned long data)
}
} else {
/* Ensure we don't false trigger in mmtimer_interrupt */
- t->it_timer.expires = 0;
+ t->it.mmtimer.expires = 0;
}
t->it_overrun_last = t->it_overrun;
out:
@@ -524,7 +524,7 @@ out:
static int sgi_timer_create(struct k_itimer *timer)
{
/* Insure that a newly created timer is off */
- timer->it_timer.magic = TIMER_OFF;
+ timer->it.mmtimer.clock = TIMER_OFF;
return 0;
}
@@ -535,8 +535,8 @@ static int sgi_timer_create(struct k_iti
*/
static int sgi_timer_del(struct k_itimer *timr)
{
- int i = timr->it_timer.magic;
- cnodeid_t nodeid = timr->it_timer.data;
+ int i = timr->it.mmtimer.clock;
+ cnodeid_t nodeid = timr->it.mmtimer.node;
mmtimer_t *t = timers + nodeid * NUM_COMPARATORS +i;
unsigned long irqflags;
@@ -544,8 +544,8 @@ static int sgi_timer_del(struct k_itimer
spin_lock_irqsave(&t->lock, irqflags);
mmtimer_disable_int(cnodeid_to_nasid(nodeid),i);
t->timer = NULL;
- timr->it_timer.magic = TIMER_OFF;
- timr->it_timer.expires = 0;
+ timr->it.mmtimer.clock = TIMER_OFF;
+ timr->it.mmtimer.expires = 0;
spin_unlock_irqrestore(&t->lock, irqflags);
}
return 0;
@@ -558,7 +558,7 @@ static int sgi_timer_del(struct k_itimer
static void sgi_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
{
- if (timr->it_timer.magic == TIMER_OFF) {
+ if (timr->it.mmtimer.clock == TIMER_OFF) {
cur_setting->it_interval.tv_nsec = 0;
cur_setting->it_interval.tv_sec = 0;
cur_setting->it_value.tv_nsec = 0;
@@ -566,8 +566,8 @@ static void sgi_timer_get(struct k_itime
return;
}
- ns_to_timespec(cur_setting->it_interval, timr->it_incr * sgi_clock_period);
- ns_to_timespec(cur_setting->it_value, (timr->it_timer.expires - rtc_time())* sgi_clock_period);
+ ns_to_timespec(cur_setting->it_interval, timr->it.mmtimer.incr * sgi_clock_period);
+ ns_to_timespec(cur_setting->it_value, (timr->it.mmtimer.expires - rtc_time())* sgi_clock_period);
return;
}
@@ -640,19 +640,19 @@ retry:
base[i].timer = timr;
base[i].cpu = smp_processor_id();
- timr->it_timer.magic = i;
- timr->it_timer.data = nodeid;
- timr->it_incr = period;
- timr->it_timer.expires = when;
+ timr->it.mmtimer.clock = i;
+ timr->it.mmtimer.node = nodeid;
+ timr->it.mmtimer.incr = period;
+ timr->it.mmtimer.expires = when;
if (period == 0) {
if (mmtimer_setup(i, when)) {
mmtimer_disable_int(-1, i);
posix_timer_event(timr, 0);
- timr->it_timer.expires = 0;
+ timr->it.mmtimer.expires = 0;
}
} else {
- timr->it_timer.expires -= period;
+ timr->it.mmtimer.expires -= period;
if (reschedule_periodic_timer(base+i))
err = -EINVAL;
}
-
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--
George Anzinger george@xxxxxxxxxx
High-res-timers: http://sourceforge.net/projects/high-res-timers/
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