linux-stable/include/linux/page_counter.h
Christophe JAILLET 09dacb7875 mm: reduce dependencies on <linux/kernel.h>
"page_counter.h" does not need <linux/kernel.h>. <linux/limits.h> is enough
to get LONG_MAX.

Files that include page_counter.h are limited. They have been compile
tested or checked.

$ git grep page_counter\.h
include/linux/hugetlb_cgroup.h: struct page_counter hugepage[HUGE_MAX_HSTATE];
	--> all files that include it have been compile tested

include/linux/memcontrol.h:#include <linux/page_counter.h>
	--> <linux/kernel.h> has been added, to be safe

include/net/sock.h:#include <linux/page_counter.h>
	--> already include <linux/kernel.h>

mm/hugetlb_cgroup.c:#include <linux/page_counter.h>
mm/memcontrol.c:#include <linux/page_counter.h>
mm/page_counter.c:#include <linux/page_counter.h>
	--> compile tested

Link: https://lkml.kernel.org/r/adfdbe21c4d06400d7bd802868762deb85cae8b6.1706908921.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 10:24:52 -08:00

84 lines
2.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_PAGE_COUNTER_H
#define _LINUX_PAGE_COUNTER_H
#include <linux/atomic.h>
#include <linux/cache.h>
#include <linux/limits.h>
#include <asm/page.h>
struct page_counter {
/*
* Make sure 'usage' does not share cacheline with any other field. The
* memcg->memory.usage is a hot member of struct mem_cgroup.
*/
atomic_long_t usage;
CACHELINE_PADDING(_pad1_);
/* effective memory.min and memory.min usage tracking */
unsigned long emin;
atomic_long_t min_usage;
atomic_long_t children_min_usage;
/* effective memory.low and memory.low usage tracking */
unsigned long elow;
atomic_long_t low_usage;
atomic_long_t children_low_usage;
unsigned long watermark;
unsigned long failcnt;
/* Keep all the read most fields in a separete cacheline. */
CACHELINE_PADDING(_pad2_);
unsigned long min;
unsigned long low;
unsigned long high;
unsigned long max;
struct page_counter *parent;
} ____cacheline_internodealigned_in_smp;
#if BITS_PER_LONG == 32
#define PAGE_COUNTER_MAX LONG_MAX
#else
#define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE)
#endif
static inline void page_counter_init(struct page_counter *counter,
struct page_counter *parent)
{
atomic_long_set(&counter->usage, 0);
counter->max = PAGE_COUNTER_MAX;
counter->parent = parent;
}
static inline unsigned long page_counter_read(struct page_counter *counter)
{
return atomic_long_read(&counter->usage);
}
void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages);
void page_counter_charge(struct page_counter *counter, unsigned long nr_pages);
bool page_counter_try_charge(struct page_counter *counter,
unsigned long nr_pages,
struct page_counter **fail);
void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages);
void page_counter_set_min(struct page_counter *counter, unsigned long nr_pages);
void page_counter_set_low(struct page_counter *counter, unsigned long nr_pages);
static inline void page_counter_set_high(struct page_counter *counter,
unsigned long nr_pages)
{
WRITE_ONCE(counter->high, nr_pages);
}
int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages);
int page_counter_memparse(const char *buf, const char *max,
unsigned long *nr_pages);
static inline void page_counter_reset_watermark(struct page_counter *counter)
{
counter->watermark = page_counter_read(counter);
}
#endif /* _LINUX_PAGE_COUNTER_H */