forked from luck/tmp_suning_uos_patched
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>
53 lines
1.4 KiB
C
53 lines
1.4 KiB
C
#ifndef _LINUX_PAGE_COUNTER_H
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#define _LINUX_PAGE_COUNTER_H
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#include <linux/atomic.h>
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#include <linux/kernel.h>
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#include <asm/page.h>
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struct page_counter {
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atomic_long_t count;
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unsigned long limit;
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struct page_counter *parent;
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/* legacy */
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unsigned long watermark;
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unsigned long failcnt;
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};
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#if BITS_PER_LONG == 32
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#define PAGE_COUNTER_MAX LONG_MAX
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#else
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#define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE)
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#endif
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static inline void page_counter_init(struct page_counter *counter,
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struct page_counter *parent)
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{
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atomic_long_set(&counter->count, 0);
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counter->limit = PAGE_COUNTER_MAX;
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counter->parent = parent;
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}
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static inline unsigned long page_counter_read(struct page_counter *counter)
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{
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return atomic_long_read(&counter->count);
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}
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void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages);
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void page_counter_charge(struct page_counter *counter, unsigned long nr_pages);
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bool page_counter_try_charge(struct page_counter *counter,
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unsigned long nr_pages,
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struct page_counter **fail);
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void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages);
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int page_counter_limit(struct page_counter *counter, unsigned long limit);
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int page_counter_memparse(const char *buf, const char *max,
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unsigned long *nr_pages);
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static inline void page_counter_reset_watermark(struct page_counter *counter)
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{
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counter->watermark = page_counter_read(counter);
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}
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#endif /* _LINUX_PAGE_COUNTER_H */
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