1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
From f351af9d4f8fc2ac1fe1252ef2e57c22ce8e77b1 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:29:37 -0500
Subject: [PATCH 203/323] mm: page_alloc: rt-friendly per-cpu pages
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.215-rt107.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 9831b1fcda36f..16200cbddaf1c 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;
}
@@ -8894,7 +8903,7 @@ 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);
@@ -8903,7 +8912,7 @@ 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
--
2.44.0
|
