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Dave Chinner
a0b02131c5
There are no more users of this API, so kill it dead, dead, dead and quietly bury the corpse in a shallow, unmarked grave in a dark forest deep in the hills... [[email protected]: added flowers to the grave] Signed-off-by: Dave Chinner <[email protected]> Signed-off-by: Glauber Costa <[email protected]> Reviewed-by: Greg Thelen <[email protected]> Acked-by: Mel Gorman <[email protected]> Cc: "Theodore Ts'o" <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Al Viro <[email protected]> Cc: Artem Bityutskiy <[email protected]> Cc: Arve Hjønnevåg <[email protected]> Cc: Carlos Maiolino <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Chuck Lever <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Gleb Natapov <[email protected]> Cc: Greg Thelen <[email protected]> Cc: J. Bruce Fields <[email protected]> Cc: Jan Kara <[email protected]> Cc: Jerome Glisse <[email protected]> Cc: John Stultz <[email protected]> Cc: KAMEZAWA Hiroyuki <[email protected]> Cc: Kent Overstreet <[email protected]> Cc: Kirill A. Shutemov <[email protected]> Cc: Marcelo Tosatti <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Steven Whitehouse <[email protected]> Cc: Thomas Hellstrom <[email protected]> Cc: Trond Myklebust <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Al Viro <[email protected]>
71 lines
2.3 KiB
C
71 lines
2.3 KiB
C
#ifndef _LINUX_SHRINKER_H
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#define _LINUX_SHRINKER_H
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/*
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* This struct is used to pass information from page reclaim to the shrinkers.
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* We consolidate the values for easier extention later.
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*
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* The 'gfpmask' refers to the allocation we are currently trying to
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* fulfil.
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*/
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struct shrink_control {
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gfp_t gfp_mask;
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/*
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* How many objects scan_objects should scan and try to reclaim.
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* This is reset before every call, so it is safe for callees
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* to modify.
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*/
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unsigned long nr_to_scan;
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/* shrink from these nodes */
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nodemask_t nodes_to_scan;
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/* current node being shrunk (for NUMA aware shrinkers) */
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int nid;
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};
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#define SHRINK_STOP (~0UL)
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/*
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* A callback you can register to apply pressure to ageable caches.
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*
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* @count_objects should return the number of freeable items in the cache. If
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* there are no objects to free or the number of freeable items cannot be
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* determined, it should return 0. No deadlock checks should be done during the
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* count callback - the shrinker relies on aggregating scan counts that couldn't
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* be executed due to potential deadlocks to be run at a later call when the
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* deadlock condition is no longer pending.
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*
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* @scan_objects will only be called if @count_objects returned a non-zero
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* value for the number of freeable objects. The callout should scan the cache
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* and attempt to free items from the cache. It should then return the number
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* of objects freed during the scan, or SHRINK_STOP if progress cannot be made
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* due to potential deadlocks. If SHRINK_STOP is returned, then no further
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* attempts to call the @scan_objects will be made from the current reclaim
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* context.
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*
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* @flags determine the shrinker abilities, like numa awareness
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*/
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struct shrinker {
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unsigned long (*count_objects)(struct shrinker *,
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struct shrink_control *sc);
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unsigned long (*scan_objects)(struct shrinker *,
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struct shrink_control *sc);
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int seeks; /* seeks to recreate an obj */
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long batch; /* reclaim batch size, 0 = default */
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unsigned long flags;
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/* These are for internal use */
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struct list_head list;
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/* objs pending delete, per node */
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atomic_long_t *nr_deferred;
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};
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#define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
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/* Flags */
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#define SHRINKER_NUMA_AWARE (1 << 0)
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extern int register_shrinker(struct shrinker *);
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extern void unregister_shrinker(struct shrinker *);
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#endif
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