diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index a50b123ab7aee7acdedc74b6c74228edfd41d0b5..0d6bb737e5a25a8aed7b2e24ab090002a2217046 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -20,6 +20,7 @@
#include <linux/atomic.h>
#include <linux/mm_types.h>
#include <linux/page-flags.h>
+#include <linux/local_lock.h>
#include <asm/page.h>
/* Free memory management - zoned buddy allocator. */
@@ -337,6 +338,7 @@ enum zone_watermarks {
#define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
#define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)
+/* Fields and list protected by pagesets local_lock in page_alloc.c */
struct per_cpu_pages {
int count; /* number of pages in the list */
int high; /* high watermark, emptying needed */
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 7723f58a9394c519485664ac7b7fd98d2bdc9172..deca67d28abba6851afe7aae1830e492a104e354 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -313,6 +313,9 @@ config DEBUG_INFO_BTF
config PAHOLE_HAS_SPLIT_BTF
def_bool $(success, test `$(PAHOLE) --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/'` -ge "119")
+config PAHOLE_HAS_ZEROSIZE_PERCPU_SUPPORT
+ def_bool $(success, test `$(PAHOLE) --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/'` -ge "122")
+
config DEBUG_INFO_BTF_MODULES
def_bool y
depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 330c7307a92bda29fdb2ab2dedde7fce66d1160e..89872ad5e872e825e891687a2c7b0d1eb063efe9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -122,6 +122,24 @@ typedef int __bitwise fpi_t;
static DEFINE_MUTEX(pcp_batch_high_lock);
#define MIN_PERCPU_PAGELIST_FRACTION (8)
+struct pagesets {
+ local_lock_t lock;
+#if defined(CONFIG_DEBUG_INFO_BTF) && \
+ !defined(CONFIG_DEBUG_LOCK_ALLOC) && \
+ !defined(CONFIG_PAHOLE_HAS_ZEROSIZE_PERCPU_SUPPORT)
+ /*
+ * pahole 1.21 and earlier gets confused by zero-sized per-CPU
+ * variables and produces invalid BTF. Ensure that
+ * sizeof(struct pagesets) != 0 for older versions of pahole.
+ */
+ char __pahole_hack;
+ #warning "pahole too old to support zero-sized struct pagesets"
+#endif
+};
+static DEFINE_PER_CPU(struct pagesets, pagesets) = {
+ .lock = INIT_LOCAL_LOCK(lock),
+};
+
#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
DEFINE_PER_CPU(int, numa_node);
EXPORT_PER_CPU_SYMBOL(numa_node);
@@ -1453,6 +1471,10 @@ static void free_pcppages_bulk(struct zone *zone, int count,
} while (--count && --batch_free && !list_empty(list));
}
+ /*
+ * local_lock_irq held so equivalent to spin_lock_irqsave for
+ * both PREEMPT_RT and non-PREEMPT_RT configurations.
+ */
spin_lock(&zone->lock);
isolated_pageblocks = has_isolate_pageblock(zone);
@@ -1573,6 +1595,11 @@ static void __free_pages_ok(struct page *page, unsigned int order,
return;
migratetype = get_pfnblock_migratetype(page, pfn);
+
+ /*
+ * TODO FIX: Disable IRQs before acquiring IRQ-safe zone->lock
+ * and protect vmstat updates.
+ */
local_irq_save(flags);
__count_vm_events(PGFREE, 1 << order);
free_one_page(page_zone(page), page, pfn, order, migratetype,
@@ -2955,6 +2982,10 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
{
int i, allocated = 0;
+ /*
+ * local_lock_irq held so equivalent to spin_lock_irqsave for
+ * both PREEMPT_RT and non-PREEMPT_RT configurations.
+ */
spin_lock(&zone->lock);
for (i = 0; i < count; ++i) {
struct page *page = __rmqueue(zone, order, migratetype,
@@ -3007,12 +3038,12 @@ 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(&pagesets.lock, flags);
batch = READ_ONCE(pcp->batch);
to_drain = min(pcp->count, batch);
if (to_drain > 0)
free_pcppages_bulk(zone, to_drain, pcp);
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pagesets.lock, flags);
}
#endif
@@ -3028,13 +3059,13 @@ static void drain_pages_zone(unsigned int cpu, struct zone *zone)
unsigned long flags;
struct per_cpu_pages *pcp;
- local_irq_save(flags);
+ local_lock_irqsave(&pagesets.lock, flags);
pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
if (pcp->count)
free_pcppages_bulk(zone, pcp->count, pcp);
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pagesets.lock, flags);
}
/*
@@ -3297,9 +3328,9 @@ void free_unref_page(struct page *page)
if (!free_unref_page_prepare(page, pfn))
return;
- local_irq_save(flags);
+ local_lock_irqsave(&pagesets.lock, flags);
free_unref_page_commit(page, pfn);
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pagesets.lock, flags);
}
/*
@@ -3319,7 +3350,7 @@ void free_unref_page_list(struct list_head *list)
set_page_private(page, pfn);
}
- local_irq_save(flags);
+ local_lock_irqsave(&pagesets.lock, flags);
list_for_each_entry_safe(page, next, list, lru) {
unsigned long pfn = page_private(page);
@@ -3332,12 +3363,12 @@ 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(&pagesets.lock, flags);
batch_count = 0;
- local_irq_save(flags);
+ local_lock_irqsave(&pagesets.lock, flags);
}
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pagesets.lock, flags);
}
/*
@@ -3494,7 +3525,7 @@ static struct page *rmqueue_pcplist(struct zone *preferred_zone,
struct page *page;
unsigned long flags;
- local_irq_save(flags);
+ local_lock_irqsave(&pagesets.lock, flags);
pcp = this_cpu_ptr(zone->per_cpu_pageset);
list = &pcp->lists[migratetype];
page = __rmqueue_pcplist(zone, migratetype, alloc_flags, pcp, list);
@@ -3502,7 +3533,7 @@ 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(&pagesets.lock, flags);
return page;
}
@@ -5103,7 +5134,7 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
goto failed;
/* Attempt the batch allocation */
- local_irq_save(flags);
+ local_lock_irqsave(&pagesets.lock, flags);
pcp = this_cpu_ptr(zone->per_cpu_pageset);
pcp_list = &pcp->lists[ac.migratetype];
@@ -5141,12 +5172,12 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
nr_populated++;
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pagesets.lock, flags);
return nr_populated;
failed_irq:
- local_irq_restore(flags);
+ local_unlock_irqrestore(&pagesets.lock, flags);
failed:
page = __alloc_pages(gfp, 0, preferred_nid, nodemask);