6071ca5201
page_counter_try_charge() currently returns 0 on success and -ENOMEM on failure, which is surprising behavior given the function name. Make it follow the expected pattern of try_stuff() functions that return a boolean true to indicate success, or false for failure. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov@virtuozzo.com Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
52 lines
1.4 KiB
C
52 lines
1.4 KiB
C
#ifndef _LINUX_PAGE_COUNTER_H
|
|
#define _LINUX_PAGE_COUNTER_H
|
|
|
|
#include <linux/atomic.h>
|
|
#include <linux/kernel.h>
|
|
#include <asm/page.h>
|
|
|
|
struct page_counter {
|
|
atomic_long_t count;
|
|
unsigned long limit;
|
|
struct page_counter *parent;
|
|
|
|
/* legacy */
|
|
unsigned long watermark;
|
|
unsigned long failcnt;
|
|
};
|
|
|
|
#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->count, 0);
|
|
counter->limit = PAGE_COUNTER_MAX;
|
|
counter->parent = parent;
|
|
}
|
|
|
|
static inline unsigned long page_counter_read(struct page_counter *counter)
|
|
{
|
|
return atomic_long_read(&counter->count);
|
|
}
|
|
|
|
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);
|
|
int page_counter_limit(struct page_counter *counter, unsigned long limit);
|
|
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 */
|