Files
android_kernel_xiaomi_sm8450/include/linux/shrinker.h
rongqianfeng bf769b7216 ANDROID: vendor_hooks: add hook and OEM data for slab shrink
Some shrinker add lock in count_objects() may cause lock contention
issues and lead all task stall on slab shrink. Add vendor hook in
do_shrink_slab() for shrinker->count_objects() latency measuring.

Add 3 oem data in shrink_control struct. Two is for
shrinker->count_objects() and shrinker->scan_objects() latency
measuring, other one to store priority, some shrinker know the reclaimer
priority can control the memory reclaim more better.

Bug: 188684131

Change-Id: I80e9d90179bb52a99c54d9a067c6fcee835bb2ad
Signed-off-by: rongqianfeng <rongqianfeng@vivo.com>
2021-06-04 11:15:20 -07:00

99 lines
3.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_SHRINKER_H
#define _LINUX_SHRINKER_H
#include <linux/android_vendor.h>
/*
* This struct is used to pass information from page reclaim to the shrinkers.
* We consolidate the values for easier extention later.
*
* The 'gfpmask' refers to the allocation we are currently trying to
* fulfil.
*/
struct shrink_control {
gfp_t gfp_mask;
/* current node being shrunk (for NUMA aware shrinkers) */
int nid;
/*
* How many objects scan_objects should scan and try to reclaim.
* This is reset before every call, so it is safe for callees
* to modify.
*/
unsigned long nr_to_scan;
/*
* How many objects did scan_objects process?
* This defaults to nr_to_scan before every call, but the callee
* should track its actual progress.
*/
unsigned long nr_scanned;
/* current memcg being shrunk (for memcg aware shrinkers) */
struct mem_cgroup *memcg;
ANDROID_OEM_DATA_ARRAY(1, 3);
};
#define SHRINK_STOP (~0UL)
#define SHRINK_EMPTY (~0UL - 1)
/*
* A callback you can register to apply pressure to ageable caches.
*
* @count_objects should return the number of freeable items in the cache. If
* there are no objects to free, it should return SHRINK_EMPTY, while 0 is
* returned in cases of the number of freeable items cannot be determined
* or shrinker should skip this cache for this time (e.g., their number
* is below shrinkable limit). No deadlock checks should be done during the
* count callback - the shrinker relies on aggregating scan counts that couldn't
* be executed due to potential deadlocks to be run at a later call when the
* deadlock condition is no longer pending.
*
* @scan_objects will only be called if @count_objects returned a non-zero
* value for the number of freeable objects. The callout should scan the cache
* and attempt to free items from the cache. It should then return the number
* of objects freed during the scan, or SHRINK_STOP if progress cannot be made
* due to potential deadlocks. If SHRINK_STOP is returned, then no further
* attempts to call the @scan_objects will be made from the current reclaim
* context.
*
* @flags determine the shrinker abilities, like numa awareness
*/
struct shrinker {
unsigned long (*count_objects)(struct shrinker *,
struct shrink_control *sc);
unsigned long (*scan_objects)(struct shrinker *,
struct shrink_control *sc);
long batch; /* reclaim batch size, 0 = default */
int seeks; /* seeks to recreate an obj */
unsigned flags;
/* These are for internal use */
struct list_head list;
#ifdef CONFIG_MEMCG
/* ID in shrinker_idr */
int id;
#endif
/* objs pending delete, per node */
atomic_long_t *nr_deferred;
};
#define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
/* Flags */
#define SHRINKER_NUMA_AWARE (1 << 0)
#define SHRINKER_MEMCG_AWARE (1 << 1)
/*
* It just makes sense when the shrinker is also MEMCG_AWARE for now,
* non-MEMCG_AWARE shrinker should not have this flag set.
*/
#define SHRINKER_NONSLAB (1 << 2)
extern int prealloc_shrinker(struct shrinker *shrinker);
extern void register_shrinker_prepared(struct shrinker *shrinker);
extern int register_shrinker(struct shrinker *shrinker);
extern void unregister_shrinker(struct shrinker *shrinker);
extern void free_prealloced_shrinker(struct shrinker *shrinker);
#endif