diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-07-03 08:29:37 -0500 |
---|---|---|
committer | Anders Roxell <anders.roxell@linaro.org> | 2015-05-08 22:30:46 +0200 |
commit | a2938e1239adf14f07fe0b7512a6c074c69de08f (patch) | |
tree | ca586d782968beb9fb454014ec4d4813779ab154 /mm | |
parent | dbdd18f9e462b1e3478a65b7f16f29a3d0359e05 (diff) |
mm: page_alloc: rt-friendly per-cpu pages
rt-friendly per-cpu pages: convert the irqs-off per-cpu locking
method into a preemptible, explicit-per-cpu-locks method.
Contains fixes from:
Peter Zijlstra <a.p.zijlstra@chello.nl>
Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/page_alloc.c | 53 |
1 files changed, 37 insertions, 16 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 7e3f1634389c..fe0b95e8320d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -59,6 +59,7 @@ #include <linux/page-debug-flags.h> #include <linux/hugetlb.h> #include <linux/sched/rt.h> +#include <linux/locallock.h> #include <asm/sections.h> #include <asm/tlbflush.h> @@ -230,6 +231,18 @@ EXPORT_SYMBOL(nr_node_ids); EXPORT_SYMBOL(nr_online_nodes); #endif +static DEFINE_LOCAL_IRQ_LOCK(pa_lock); + +#ifdef CONFIG_PREEMPT_RT_BASE +# define cpu_lock_irqsave(cpu, flags) \ + spin_lock_irqsave(&per_cpu(pa_lock, cpu).lock, flags) +# define cpu_unlock_irqrestore(cpu, flags) \ + spin_unlock_irqrestore(&per_cpu(pa_lock, cpu).lock, flags) +#else +# define cpu_lock_irqsave(cpu, flags) local_irq_save(flags) +# define cpu_unlock_irqrestore(cpu, flags) local_irq_restore(flags) +#endif + int page_group_by_mobility_disabled __read_mostly; void set_pageblock_migratetype(struct page *page, int migratetype) @@ -773,11 +786,11 @@ static void __free_pages_ok(struct page *page, unsigned int order) return; migratetype = get_pfnblock_migratetype(page, pfn); - local_irq_save(flags); + local_lock_irqsave(pa_lock, flags); __count_vm_events(PGFREE, 1 << order); set_freepage_migratetype(page, migratetype); free_one_page(page_zone(page), page, pfn, order, migratetype); - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); } void __init __free_pages_bootmem(struct page *page, unsigned int order) @@ -1253,14 +1266,14 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) unsigned long flags; int to_drain, batch; - local_irq_save(flags); + local_lock_irqsave(pa_lock, flags); batch = ACCESS_ONCE(pcp->batch); to_drain = min(pcp->count, batch); if (to_drain > 0) { free_pcppages_bulk(zone, to_drain, pcp); pcp->count -= to_drain; } - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); } #endif @@ -1280,7 +1293,7 @@ static void drain_pages(unsigned int cpu) struct per_cpu_pageset *pset; struct per_cpu_pages *pcp; - local_irq_save(flags); + cpu_lock_irqsave(cpu, flags); pset = per_cpu_ptr(zone->pageset, cpu); pcp = &pset->pcp; @@ -1288,7 +1301,7 @@ static void drain_pages(unsigned int cpu) free_pcppages_bulk(zone, pcp->count, pcp); pcp->count = 0; } - local_irq_restore(flags); + cpu_unlock_irqrestore(cpu, flags); } } @@ -1341,7 +1354,12 @@ void drain_all_pages(void) else cpumask_clear_cpu(cpu, &cpus_with_pcps); } +#ifndef CONFIG_PREEMPT_RT_BASE on_each_cpu_mask(&cpus_with_pcps, drain_local_pages, NULL, 1); +#else + for_each_cpu(cpu, &cpus_with_pcps) + drain_pages(cpu); +#endif } #ifdef CONFIG_HIBERNATION @@ -1397,7 +1415,7 @@ void free_hot_cold_page(struct page *page, bool cold) migratetype = get_pfnblock_migratetype(page, pfn); set_freepage_migratetype(page, migratetype); - local_irq_save(flags); + local_lock_irqsave(pa_lock, flags); __count_vm_event(PGFREE); /* @@ -1428,7 +1446,7 @@ void free_hot_cold_page(struct page *page, bool cold) } out: - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); } /* @@ -1558,7 +1576,7 @@ again: struct per_cpu_pages *pcp; struct list_head *list; - local_irq_save(flags); + local_lock_irqsave(pa_lock, flags); pcp = &this_cpu_ptr(zone->pageset)->pcp; list = &pcp->lists[migratetype]; if (list_empty(list)) { @@ -1590,13 +1608,15 @@ again: */ WARN_ON_ONCE(order > 1); } - spin_lock_irqsave(&zone->lock, flags); + local_spin_lock_irqsave(pa_lock, &zone->lock, flags); page = __rmqueue(zone, order, migratetype); - spin_unlock(&zone->lock); - if (!page) + if (!page) { + spin_unlock(&zone->lock); goto failed; + } __mod_zone_freepage_state(zone, -(1 << order), get_freepage_migratetype(page)); + spin_unlock(&zone->lock); } __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order)); @@ -1606,7 +1626,7 @@ again: __count_zone_vm_events(PGALLOC, zone, 1 << order); zone_statistics(preferred_zone, zone, gfp_flags); - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); VM_BUG_ON_PAGE(bad_range(zone, page), page); if (prep_new_page(page, order, gfp_flags)) @@ -1614,7 +1634,7 @@ again: return page; failed: - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); return NULL; } @@ -5565,6 +5585,7 @@ static int page_alloc_cpu_notify(struct notifier_block *self, void __init page_alloc_init(void) { hotcpu_notifier(page_alloc_cpu_notify, 0); + local_irq_lock_init(pa_lock); } /* @@ -6459,7 +6480,7 @@ void zone_pcp_reset(struct zone *zone) struct per_cpu_pageset *pset; /* avoid races with drain_pages() */ - local_irq_save(flags); + local_lock_irqsave(pa_lock, flags); if (zone->pageset != &boot_pageset) { for_each_online_cpu(cpu) { pset = per_cpu_ptr(zone->pageset, cpu); @@ -6468,7 +6489,7 @@ void zone_pcp_reset(struct zone *zone) free_percpu(zone->pageset); zone->pageset = &boot_pageset; } - local_irq_restore(flags); + local_unlock_irqrestore(pa_lock, flags); } #ifdef CONFIG_MEMORY_HOTREMOVE |