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#ifndef JEMALLOC_INTERNAL_PAC_H
#define JEMALLOC_INTERNAL_PAC_H
#include "jemalloc/internal/exp_grow.h"
#include "jemalloc/internal/pai.h"
#include "san_bump.h"
/*
* Page allocator classic; an implementation of the PAI interface that:
* - Can be used for arenas with custom extent hooks.
* - Can always satisfy any allocation request (including highly-fragmentary
* ones).
* - Can use efficient OS-level zeroing primitives for demand-filled pages.
*/
/* How "eager" decay/purging should be. */
enum pac_purge_eagerness_e {
PAC_PURGE_ALWAYS,
PAC_PURGE_NEVER,
PAC_PURGE_ON_EPOCH_ADVANCE
};
typedef enum pac_purge_eagerness_e pac_purge_eagerness_t;
typedef struct pac_decay_stats_s pac_decay_stats_t;
struct pac_decay_stats_s {
/* Total number of purge sweeps. */
locked_u64_t npurge;
/* Total number of madvise calls made. */
locked_u64_t nmadvise;
/* Total number of pages purged. */
locked_u64_t purged;
};
typedef struct pac_estats_s pac_estats_t;
struct pac_estats_s {
/*
* Stats for a given index in the range [0, SC_NPSIZES] in the various
* ecache_ts.
* We track both bytes and # of extents: two extents in the same bucket
* may have different sizes if adjacent size classes differ by more than
* a page, so bytes cannot always be derived from # of extents.
*/
size_t ndirty;
size_t dirty_bytes;
size_t nmuzzy;
size_t muzzy_bytes;
size_t nretained;
size_t retained_bytes;
};
typedef struct pac_stats_s pac_stats_t;
struct pac_stats_s {
pac_decay_stats_t decay_dirty;
pac_decay_stats_t decay_muzzy;
/*
* Number of unused virtual memory bytes currently retained. Retained
* bytes are technically mapped (though always decommitted or purged),
* but they are excluded from the mapped statistic (above).
*/
size_t retained; /* Derived. */
/*
* Number of bytes currently mapped, excluding retained memory (and any
* base-allocated memory, which is tracked by the arena stats).
*
* We name this "pac_mapped" to avoid confusion with the arena_stats
* "mapped".
*/
atomic_zu_t pac_mapped;
/* VM space had to be leaked (undocumented). Normally 0. */
atomic_zu_t abandoned_vm;
};
typedef struct pac_s pac_t;
struct pac_s {
/*
* Must be the first member (we convert it to a PAC given only a
* pointer). The handle to the allocation interface.
*/
pai_t pai;
/*
* Collections of extents that were previously allocated. These are
* used when allocating extents, in an attempt to re-use address space.
*
* Synchronization: internal.
*/
ecache_t ecache_dirty;
ecache_t ecache_muzzy;
ecache_t ecache_retained;
base_t *base;
emap_t *emap;
edata_cache_t *edata_cache;
/* The grow info for the retained ecache. */
exp_grow_t exp_grow;
malloc_mutex_t grow_mtx;
/* Special allocator for guarded frequently reused extents. */
san_bump_alloc_t sba;
/* How large extents should be before getting auto-purged. */
atomic_zu_t oversize_threshold;
/*
* Decay-based purging state, responsible for scheduling extent state
* transitions.
*
* Synchronization: via the internal mutex.
*/
decay_t decay_dirty; /* dirty --> muzzy */
decay_t decay_muzzy; /* muzzy --> retained */
malloc_mutex_t *stats_mtx;
pac_stats_t *stats;
/* Extent serial number generator state. */
atomic_zu_t extent_sn_next;
};
bool pac_init(tsdn_t *tsdn, pac_t *pac, base_t *base, emap_t *emap,
edata_cache_t *edata_cache, nstime_t *cur_time, size_t oversize_threshold,
ssize_t dirty_decay_ms, ssize_t muzzy_decay_ms, pac_stats_t *pac_stats,
malloc_mutex_t *stats_mtx);
static inline size_t
pac_mapped(pac_t *pac) {
return atomic_load_zu(&pac->stats->pac_mapped, ATOMIC_RELAXED);
}
static inline ehooks_t *
pac_ehooks_get(pac_t *pac) {
return base_ehooks_get(pac->base);
}
/*
* All purging functions require holding decay->mtx. This is one of the few
* places external modules are allowed to peek inside pa_shard_t internals.
*/
/*
* Decays the number of pages currently in the ecache. This might not leave the
* ecache empty if other threads are inserting dirty objects into it
* concurrently with the call.
*/
void pac_decay_all(tsdn_t *tsdn, pac_t *pac, decay_t *decay,
pac_decay_stats_t *decay_stats, ecache_t *ecache, bool fully_decay);
/*
* Updates decay settings for the current time, and conditionally purges in
* response (depending on decay_purge_setting). Returns whether or not the
* epoch advanced.
*/
bool pac_maybe_decay_purge(tsdn_t *tsdn, pac_t *pac, decay_t *decay,
pac_decay_stats_t *decay_stats, ecache_t *ecache,
pac_purge_eagerness_t eagerness);
/*
* Gets / sets the maximum amount that we'll grow an arena down the
* grow-retained pathways (unless forced to by an allocaction request).
*
* Set new_limit to NULL if it's just a query, or old_limit to NULL if you don't
* care about the previous value.
*
* Returns true on error (if the new limit is not valid).
*/
bool pac_retain_grow_limit_get_set(tsdn_t *tsdn, pac_t *pac, size_t *old_limit,
size_t *new_limit);
bool pac_decay_ms_set(tsdn_t *tsdn, pac_t *pac, extent_state_t state,
ssize_t decay_ms, pac_purge_eagerness_t eagerness);
ssize_t pac_decay_ms_get(pac_t *pac, extent_state_t state);
void pac_reset(tsdn_t *tsdn, pac_t *pac);
void pac_destroy(tsdn_t *tsdn, pac_t *pac);
#endif /* JEMALLOC_INTERNAL_PAC_H */
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