linux-stable/mm/cma.h
Anshuman Khandual b9ad003af1 mm/cma: add sysfs file 'release_pages_success'
This adds the following new sysfs file tracking the number of successfully
released pages from a given CMA heap area.  This file will be available
via CONFIG_CMA_SYSFS and help in determining active CMA pages available on
the CMA heap area.  This adds a new 'nr_pages_released' (CONFIG_CMA_SYSFS)
into 'struct cma' which gets updated during cma_release().

/sys/kernel/mm/cma/<cma-heap-area>/release_pages_success

After this change, an user will be able to find active CMA pages available
in a given CMA heap area via the following method.

Active pages = alloc_pages_success - release_pages_success

That's valuable information for both software designers, and system admins
as it allows them to tune the number of CMA pages available in the system.
This increases user visibility for allocated CMA area and its
utilization.

Link: https://lkml.kernel.org/r/20240206045731.472759-1-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 10:24:57 -08:00

58 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __MM_CMA_H__
#define __MM_CMA_H__
#include <linux/debugfs.h>
#include <linux/kobject.h>
struct cma_kobject {
struct kobject kobj;
struct cma *cma;
};
struct cma {
unsigned long base_pfn;
unsigned long count;
unsigned long *bitmap;
unsigned int order_per_bit; /* Order of pages represented by one bit */
spinlock_t lock;
#ifdef CONFIG_CMA_DEBUGFS
struct hlist_head mem_head;
spinlock_t mem_head_lock;
struct debugfs_u32_array dfs_bitmap;
#endif
char name[CMA_MAX_NAME];
#ifdef CONFIG_CMA_SYSFS
/* the number of CMA page successful allocations */
atomic64_t nr_pages_succeeded;
/* the number of CMA page allocation failures */
atomic64_t nr_pages_failed;
/* the number of CMA page released */
atomic64_t nr_pages_released;
/* kobject requires dynamic object */
struct cma_kobject *cma_kobj;
#endif
bool reserve_pages_on_error;
};
extern struct cma cma_areas[MAX_CMA_AREAS];
extern unsigned cma_area_count;
static inline unsigned long cma_bitmap_maxno(struct cma *cma)
{
return cma->count >> cma->order_per_bit;
}
#ifdef CONFIG_CMA_SYSFS
void cma_sysfs_account_success_pages(struct cma *cma, unsigned long nr_pages);
void cma_sysfs_account_fail_pages(struct cma *cma, unsigned long nr_pages);
void cma_sysfs_account_release_pages(struct cma *cma, unsigned long nr_pages);
#else
static inline void cma_sysfs_account_success_pages(struct cma *cma,
unsigned long nr_pages) {};
static inline void cma_sysfs_account_fail_pages(struct cma *cma,
unsigned long nr_pages) {};
static inline void cma_sysfs_account_release_pages(struct cma *cma,
unsigned long nr_pages) {};
#endif
#endif