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From 3e154f65955f6e6664afe437446c1cf8c1409f5d Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:29:37 -0500
Subject: [PATCH 206/296] mm: page_alloc: rt-friendly per-cpu pages
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.35-rt39.tar.xz
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 | 47 ++++++++++++++++++++++++++++-------------------
1 file changed, 28 insertions(+), 19 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b8350cbe66f9..287f3afc3cf1 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -61,6 +61,7 @@
#include <linux/hugetlb.h>
#include <linux/sched/rt.h>
#include <linux/sched/mm.h>
+#include <linux/local_lock.h>
#include <linux/page_owner.h>
#include <linux/kthread.h>
#include <linux/memcontrol.h>
@@ -386,6 +387,13 @@ EXPORT_SYMBOL(nr_node_ids);
EXPORT_SYMBOL(nr_online_nodes);
#endif
+struct pa_lock {
+ local_lock_t l;
+};
+static DEFINE_PER_CPU(struct pa_lock, pa_lock) = {
+ .l = INIT_LOCAL_LOCK(l),
+};
+
int page_group_by_mobility_disabled __read_mostly;
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
@@ -1543,11 +1551,11 @@ 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.l, flags);
__count_vm_events(PGFREE, 1 << order);
free_one_page(page_zone(page), page, pfn, order, migratetype,
fpi_flags);
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pa_lock.l, flags);
}
void __free_pages_core(struct page *page, unsigned int order)
@@ -2961,13 +2969,13 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
int to_drain, batch;
LIST_HEAD(dst);
- local_irq_save(flags);
+ local_lock_irqsave(&pa_lock.l, flags);
batch = READ_ONCE(pcp->batch);
to_drain = min(pcp->count, batch);
if (to_drain > 0)
isolate_pcp_pages(to_drain, pcp, &dst);
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pa_lock.l, flags);
if (to_drain > 0)
free_pcppages_bulk(zone, &dst, false);
@@ -2989,7 +2997,7 @@ static void drain_pages_zone(unsigned int cpu, struct zone *zone)
LIST_HEAD(dst);
int count;
- local_irq_save(flags);
+ local_lock_irqsave(&pa_lock.l, flags);
pset = per_cpu_ptr(zone->pageset, cpu);
pcp = &pset->pcp;
@@ -2997,7 +3005,7 @@ static void drain_pages_zone(unsigned int cpu, struct zone *zone)
if (count)
isolate_pcp_pages(count, pcp, &dst);
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pa_lock.l, flags);
if (count)
free_pcppages_bulk(zone, &dst, false);
@@ -3248,9 +3256,9 @@ void free_unref_page(struct page *page)
if (!free_unref_page_prepare(page, pfn))
return;
- local_irq_save(flags);
+ local_lock_irqsave(&pa_lock.l, flags);
free_unref_page_commit(page, pfn, &dst);
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pa_lock.l, flags);
if (!list_empty(&dst))
free_pcppages_bulk(zone, &dst, false);
}
@@ -3277,7 +3285,7 @@ void free_unref_page_list(struct list_head *list)
set_page_private(page, pfn);
}
- local_irq_save(flags);
+ local_lock_irqsave(&pa_lock.l, flags);
list_for_each_entry_safe(page, next, list, lru) {
unsigned long pfn = page_private(page);
enum zone_type type;
@@ -3292,12 +3300,12 @@ void free_unref_page_list(struct list_head *list)
* a large list of pages to free.
*/
if (++batch_count == SWAP_CLUSTER_MAX) {
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pa_lock.l, flags);
batch_count = 0;
- local_irq_save(flags);
+ local_lock_irqsave(&pa_lock.l, flags);
}
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pa_lock.l, flags);
for (i = 0; i < __MAX_NR_ZONES; ) {
struct page *page;
@@ -3468,7 +3476,7 @@ static struct page *rmqueue_pcplist(struct zone *preferred_zone,
struct page *page;
unsigned long flags;
- local_irq_save(flags);
+ local_lock_irqsave(&pa_lock.l, flags);
pcp = &this_cpu_ptr(zone->pageset)->pcp;
list = &pcp->lists[migratetype];
page = __rmqueue_pcplist(zone, migratetype, alloc_flags, pcp, list);
@@ -3476,7 +3484,7 @@ static struct page *rmqueue_pcplist(struct zone *preferred_zone,
__count_zid_vm_events(PGALLOC, page_zonenum(page), 1);
zone_statistics(preferred_zone, zone);
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pa_lock.l, flags);
return page;
}
@@ -3510,7 +3518,8 @@ struct page *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_lock_irqsave(&pa_lock.l, flags);
+ spin_lock(&zone->lock);
do {
page = NULL;
@@ -3536,7 +3545,7 @@ struct page *rmqueue(struct zone *preferred_zone,
__count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
zone_statistics(preferred_zone, zone);
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pa_lock.l, flags);
out:
/* Separate test+clear to avoid unnecessary atomics */
@@ -3549,7 +3558,7 @@ struct page *rmqueue(struct zone *preferred_zone,
return page;
failed:
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pa_lock.l, flags);
return NULL;
}
@@ -8794,7 +8803,7 @@ 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.l, flags);
if (zone->pageset != &boot_pageset) {
for_each_online_cpu(cpu) {
pset = per_cpu_ptr(zone->pageset, cpu);
@@ -8803,7 +8812,7 @@ void zone_pcp_reset(struct zone *zone)
free_percpu(zone->pageset);
zone->pageset = &boot_pageset;
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pa_lock.l, flags);
}
#ifdef CONFIG_MEMORY_HOTREMOVE
--
2.30.2
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