Jetpack/kernel/kernel-4.9/rt-patches/0100-mm-page_alloc-rt-frien...

209 lines
5.9 KiB
Diff

From 4d512a25ca20f3ce37939e91ca1adc75c2b68305 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:29:37 -0500
Subject: [PATCH 100/352] 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>
---
mm/page_alloc.c | 57 +++++++++++++++++++++++++++++++++++++++++----------------
1 file changed, 41 insertions(+), 16 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 26ba311..c717779 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -61,6 +61,7 @@
#include <linux/page_ext.h>
#include <linux/hugetlb.h>
#include <linux/sched/rt.h>
+#include <linux/locallock.h>
#include <linux/page_owner.h>
#include <linux/kthread.h>
#include <linux/memcontrol.h>
@@ -293,6 +294,18 @@ 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;
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
@@ -1276,10 +1289,10 @@ 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);
free_one_page(page_zone(page), page, pfn, order, migratetype);
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
}
static void __init __free_pages_boot_core(struct page *page, unsigned int order)
@@ -2296,14 +2309,14 @@ 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 = READ_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
@@ -2320,7 +2333,7 @@ static void drain_pages_zone(unsigned int cpu, struct zone *zone)
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;
@@ -2328,7 +2341,7 @@ static void drain_pages_zone(unsigned int cpu, struct zone *zone)
free_pcppages_bulk(zone, pcp->count, pcp);
pcp->count = 0;
}
- local_irq_restore(flags);
+ cpu_unlock_irqrestore(cpu, flags);
}
/*
@@ -2415,7 +2428,16 @@ void drain_all_pages(struct zone *zone)
else
cpumask_clear_cpu(cpu, &cpus_with_pcps);
}
+#ifndef CONFIG_PREEMPT_RT_BASE
on_each_cpu_mask(&cpus_with_pcps, drain_local_pages, zone, 1);
+#else
+ for_each_cpu(cpu, &cpus_with_pcps) {
+ if (zone)
+ drain_pages_zone(cpu, zone);
+ else
+ drain_pages(cpu);
+ }
+#endif
}
#ifdef CONFIG_HIBERNATION
@@ -2475,7 +2497,7 @@ void free_hot_cold_page(struct page *page, bool cold)
migratetype = get_pfnblock_migratetype(page, pfn);
set_pcppage_migratetype(page, migratetype);
- local_irq_save(flags);
+ local_lock_irqsave(pa_lock, flags);
__count_vm_event(PGFREE);
/*
@@ -2506,7 +2528,7 @@ void free_hot_cold_page(struct page *page, bool cold)
}
out:
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
}
/*
@@ -2641,7 +2663,7 @@ struct page *buffered_rmqueue(struct zone *preferred_zone,
struct per_cpu_pages *pcp;
struct list_head *list;
- local_irq_save(flags);
+ local_lock_irqsave(pa_lock, flags);
do {
pcp = &this_cpu_ptr(zone->pageset)->pcp;
list = &pcp->lists[migratetype];
@@ -2668,7 +2690,7 @@ struct page *buffered_rmqueue(struct zone *preferred_zone,
* allocate greater than order-1 page units with __GFP_NOFAIL.
*/
WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
- spin_lock_irqsave(&zone->lock, flags);
+ local_spin_lock_irqsave(pa_lock, &zone->lock, flags);
do {
page = NULL;
@@ -2680,22 +2702,24 @@ struct page *buffered_rmqueue(struct zone *preferred_zone,
if (!page)
page = __rmqueue(zone, order, migratetype);
} while (page && check_new_pages(page, order));
- spin_unlock(&zone->lock);
- if (!page)
+ if (!page) {
+ spin_unlock(&zone->lock);
goto failed;
+ }
__mod_zone_freepage_state(zone, -(1 << order),
get_pcppage_migratetype(page));
+ spin_unlock(&zone->lock);
}
__count_zid_vm_events(PGALLOC, page_zonenum(page), 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);
return page;
failed:
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
return NULL;
}
@@ -6602,6 +6626,7 @@ 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);
}
/*
@@ -7443,7 +7468,7 @@ 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);
@@ -7452,7 +7477,7 @@ 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
--
2.7.4