[PATCH] shrink mmtimer memory size
This greatly reduces the amount of memory used by mmtimer on smaller
machines with large values of MAX_COMPACT_NODES.
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/char/mmtimer.c b/drivers/char/mmtimer.c
index 78c89a3..c923781 100644
--- a/drivers/char/mmtimer.c
+++ b/drivers/char/mmtimer.c
@@ -1,11 +1,11 @@
/*
- * Intel Multimedia Timer device implementation for SGI SN platforms.
+ * Timer device implementation for SGI SN platforms.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
- * Copyright (c) 2001-2004 Silicon Graphics, Inc. All rights reserved.
+ * Copyright (c) 2001-2006 Silicon Graphics, Inc. All rights reserved.
*
* This driver exports an API that should be supportable by any HPET or IA-PC
* multimedia timer. The code below is currently specific to the SGI Altix
@@ -45,7 +45,7 @@
/* name of the device, usually in /dev */
#define MMTIMER_NAME "mmtimer"
#define MMTIMER_DESC "SGI Altix RTC Timer"
-#define MMTIMER_VERSION "2.0"
+#define MMTIMER_VERSION "2.1"
#define RTC_BITS 55 /* 55 bits for this implementation */
@@ -227,10 +227,7 @@
struct tasklet_struct tasklet;
} mmtimer_t;
-/*
- * Total number of comparators is comparators/node * MAX nodes/running kernel
- */
-static mmtimer_t timers[NUM_COMPARATORS*MAX_COMPACT_NODES];
+static mmtimer_t ** timers;
/**
* mmtimer_ioctl - ioctl interface for /dev/mmtimer
@@ -441,29 +438,29 @@
mmtimer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
int i;
- mmtimer_t *base = timers + cpu_to_node(smp_processor_id()) *
- NUM_COMPARATORS;
unsigned long expires = 0;
int result = IRQ_NONE;
+ unsigned indx = cpu_to_node(smp_processor_id());
/*
* Do this once for each comparison register
*/
for (i = 0; i < NUM_COMPARATORS; i++) {
+ mmtimer_t *base = timers[indx] + i;
/* Make sure this doesn't get reused before tasklet_sched */
- spin_lock(&base[i].lock);
- if (base[i].cpu == smp_processor_id()) {
- if (base[i].timer)
- expires = base[i].timer->it.mmtimer.expires;
+ spin_lock(&base->lock);
+ if (base->cpu == smp_processor_id()) {
+ if (base->timer)
+ expires = base->timer->it.mmtimer.expires;
/* expires test won't work with shared irqs */
if ((mmtimer_int_pending(i) > 0) ||
(expires && (expires < rtc_time()))) {
mmtimer_clr_int_pending(i);
- tasklet_schedule(&base[i].tasklet);
+ tasklet_schedule(&base->tasklet);
result = IRQ_HANDLED;
}
}
- spin_unlock(&base[i].lock);
+ spin_unlock(&base->lock);
expires = 0;
}
return result;
@@ -523,7 +520,7 @@
{
int i = timr->it.mmtimer.clock;
cnodeid_t nodeid = timr->it.mmtimer.node;
- mmtimer_t *t = timers + nodeid * NUM_COMPARATORS +i;
+ mmtimer_t *t = timers[nodeid] + i;
unsigned long irqflags;
if (i != TIMER_OFF) {
@@ -609,11 +606,11 @@
preempt_disable();
nodeid = cpu_to_node(smp_processor_id());
- base = timers + nodeid * NUM_COMPARATORS;
retry:
/* Don't use an allocated timer, or a deleted one that's pending */
for(i = 0; i< NUM_COMPARATORS; i++) {
- if (!base[i].timer && !base[i].tasklet.state) {
+ base = timers[nodeid] + i;
+ if (!base->timer && !base->tasklet.state) {
break;
}
}
@@ -623,14 +620,14 @@
return -EBUSY;
}
- spin_lock_irqsave(&base[i].lock, irqflags);
+ spin_lock_irqsave(&base->lock, irqflags);
- if (base[i].timer || base[i].tasklet.state != 0) {
- spin_unlock_irqrestore(&base[i].lock, irqflags);
+ if (base->timer || base->tasklet.state != 0) {
+ spin_unlock_irqrestore(&base->lock, irqflags);
goto retry;
}
- base[i].timer = timr;
- base[i].cpu = smp_processor_id();
+ base->timer = timr;
+ base->cpu = smp_processor_id();
timr->it.mmtimer.clock = i;
timr->it.mmtimer.node = nodeid;
@@ -645,11 +642,11 @@
}
} else {
timr->it.mmtimer.expires -= period;
- if (reschedule_periodic_timer(base+i))
+ if (reschedule_periodic_timer(base))
err = -EINVAL;
}
- spin_unlock_irqrestore(&base[i].lock, irqflags);
+ spin_unlock_irqrestore(&base->lock, irqflags);
preempt_enable();
@@ -675,6 +672,7 @@
static int __init mmtimer_init(void)
{
unsigned i;
+ cnodeid_t node, maxn = -1;
if (!ia64_platform_is("sn2"))
return -1;
@@ -691,14 +689,6 @@
mmtimer_femtoperiod = ((unsigned long)1E15 + sn_rtc_cycles_per_second /
2) / sn_rtc_cycles_per_second;
- for (i=0; i< NUM_COMPARATORS*MAX_COMPACT_NODES; i++) {
- spin_lock_init(&timers[i].lock);
- timers[i].timer = NULL;
- timers[i].cpu = 0;
- timers[i].i = i % NUM_COMPARATORS;
- tasklet_init(&timers[i].tasklet, mmtimer_tasklet, (unsigned long) (timers+i));
- }
-
if (request_irq(SGI_MMTIMER_VECTOR, mmtimer_interrupt, SA_PERCPU_IRQ, MMTIMER_NAME, NULL)) {
printk(KERN_WARNING "%s: unable to allocate interrupt.",
MMTIMER_NAME);
@@ -712,6 +702,40 @@
return -1;
}
+ /* Get max numbered node, calculate slots needed */
+ for_each_online_node(node) {
+ maxn = node;
+ }
+ maxn++;
+
+ /* Allocate list of node ptrs to mmtimer_t's */
+ timers = kmalloc(sizeof(mmtimer_t *)*maxn, GFP_KERNEL);
+ if (timers == NULL) {
+ printk(KERN_ERR "%s: failed to allocate memory for device\n",
+ MMTIMER_NAME);
+ return -1;
+ }
+
+ /* Allocate mmtimer_t's for each online node */
+ for_each_online_node(node) {
+ timers[node] = kmalloc_node(sizeof(mmtimer_t)*NUM_COMPARATORS, GFP_KERNEL, node);
+ if (timers[node] == NULL) {
+ printk(KERN_ERR "%s: failed to allocate memory for device\n",
+ MMTIMER_NAME);
+ return -1;
+ }
+ for (i=0; i< NUM_COMPARATORS; i++) {
+ mmtimer_t * base = timers[node] + i;
+
+ spin_lock_init(&base->lock);
+ base->timer = NULL;
+ base->cpu = 0;
+ base->i = i;
+ tasklet_init(&base->tasklet, mmtimer_tasklet,
+ (unsigned long) (base));
+ }
+ }
+
sgi_clock_period = sgi_clock.res = NSEC_PER_SEC / sn_rtc_cycles_per_second;
register_posix_clock(CLOCK_SGI_CYCLE, &sgi_clock);