linux/mm/cma.h
Minchan Kim 43ca106fa8 mm: cma: support sysfs
Since CMA is getting used more widely, it's more important to keep
monitoring CMA statistics for system health since it's directly related to
user experience.

This patch introduces sysfs statistics for CMA, in order to provide some
basic monitoring of the CMA allocator.

 * the number of CMA page successful allocations
 * the number of CMA page allocation failures

These two values allow the user to calcuate the allocation
failure rate for each CMA area.

e.g.)
  /sys/kernel/mm/cma/WIFI/alloc_pages_[success|fail]
  /sys/kernel/mm/cma/SENSOR/alloc_pages_[success|fail]
  /sys/kernel/mm/cma/BLUETOOTH/alloc_pages_[success|fail]

The cma_stat was intentionally allocated by dynamic allocation
to harmonize with kobject lifetime management.
https://lore.kernel.org/linux-mm/YCOAmXqt6dZkCQYs@kroah.com/

Link: https://lkml.kernel.org/r/20210324230759.2213957-1-minchan@kernel.org
Link: https://lore.kernel.org/linux-mm/20210316100433.17665-1-colin.king@canonical.com/
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Colin Ian King <colin.king@canonical.com>

Tested-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: John Dias <joaodias@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05 11:27:24 -07:00

52 lines
1.4 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;
/* kobject requires dynamic object */
struct cma_kobject *cma_kobj;
#endif
};
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);
#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) {};
#endif
#endif