From: Dimitri Sivanich Date: Fri, 6 Jan 2006 17:33:41 +0000 (-0600) Subject: [PATCH] shrink mmtimer memory size X-Git-Tag: v2.6.16-rc1~935^2~6 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=76832c28de4fabbf32fe1e5a25194724a3430070;p=linux-2.6-omap-h63xx.git [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 Signed-off-by: Christoph Lameter Signed-off-by: Linus Torvalds --- diff --git a/drivers/char/mmtimer.c b/drivers/char/mmtimer.c index 78c89a3e782..c92378121b4 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 @@ MODULE_LICENSE("GPL"); /* 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 @@ typedef struct mmtimer { 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 @@ static irqreturn_t 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 @@ static int sgi_timer_del(struct k_itimer *timr) { 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 @@ static int sgi_timer_set(struct k_itimer *timr, int flags, 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 @@ retry: 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 @@ retry: } } 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 struct k_clock sgi_clock = { static int __init mmtimer_init(void) { unsigned i; + cnodeid_t node, maxn = -1; if (!ia64_platform_is("sn2")) return -1; @@ -691,14 +689,6 @@ static int __init mmtimer_init(void) 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 @@ static int __init mmtimer_init(void) 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);