Convert arena_decay_t's time to be atomically synchronized.

This commit is contained in:
Jason Evans 2017-03-01 11:21:18 -08:00
parent ff55f07eb6
commit d61a5f76b2
4 changed files with 33 additions and 17 deletions

View File

@ -39,7 +39,7 @@ void arena_extent_ralloc_large_shrink(tsdn_t *tsdn, arena_t *arena,
extent_t *extent, size_t oldsize);
void arena_extent_ralloc_large_expand(tsdn_t *tsdn, arena_t *arena,
extent_t *extent, size_t oldsize);
ssize_t arena_decay_time_get(tsdn_t *tsdn, arena_t *arena);
ssize_t arena_decay_time_get(arena_t *arena);
bool arena_decay_time_set(tsdn_t *tsdn, arena_t *arena, ssize_t decay_time);
void arena_purge(tsdn_t *tsdn, arena_t *arena, bool all);
void arena_maybe_purge(tsdn_t *tsdn, arena_t *arena);

View File

@ -36,15 +36,22 @@ struct arena_bin_info_s {
bitmap_info_t bitmap_info;
};
typedef union {
size_t u; /* Used for atomic operations. */
ssize_t s; /* Time may be negative (means "never"). */
} arena_decay_time_t;
struct arena_decay_s {
/* Synchronizes all fields. */
/* Synchronizes all non-atomic fields. */
malloc_mutex_t mtx;
/*
* Approximate time in seconds from the creation of a set of unused
* dirty pages until an equivalent set of unused dirty pages is purged
* and/or reused.
*
* Synchronization: atomic.
*/
ssize_t time;
arena_decay_time_t time;
/* time / SMOOTHSTEP_NSTEPS. */
nstime_t interval;
/*

View File

@ -157,7 +157,7 @@ arena_basic_stats_merge(tsdn_t *tsdn, arena_t *arena, unsigned *nthreads,
const char **dss, ssize_t *decay_time, size_t *nactive, size_t *ndirty) {
*nthreads += arena_nthreads_get(arena, false);
*dss = dss_prec_names[arena_dss_prec_get(arena)];
*decay_time = arena_decay_time_get(tsdn, arena);
*decay_time = arena_decay_time_get(arena);
*nactive += atomic_read_zu(&arena->nactive);
*ndirty += extents_npages_get(&arena->extents_cached);
}
@ -491,6 +491,20 @@ arena_extent_ralloc_large_expand(tsdn_t *tsdn, arena_t *arena, extent_t *extent,
arena_nactive_add(arena, udiff >> LG_PAGE);
}
static ssize_t
arena_decay_time_read(arena_t *arena) {
arena_decay_time_t dt;
dt.u = atomic_read_zu(&arena->decay.time.u);
return dt.s;
}
static void
arena_decay_time_write(arena_t *arena, ssize_t decay_time) {
arena_decay_time_t dt;
dt.s = decay_time;
atomic_write_zu(&arena->decay.time.u, dt.u);
}
static void
arena_decay_deadline_init(arena_t *arena) {
/*
@ -499,7 +513,7 @@ arena_decay_deadline_init(arena_t *arena) {
*/
nstime_copy(&arena->decay.deadline, &arena->decay.epoch);
nstime_add(&arena->decay.deadline, &arena->decay.interval);
if (arena->decay.time > 0) {
if (arena_decay_time_read(arena) > 0) {
nstime_t jitter;
nstime_init(&jitter, prng_range_u64(&arena->decay.jitter_state,
@ -615,7 +629,7 @@ arena_decay_epoch_advance(tsdn_t *tsdn, arena_t *arena, const nstime_t *time) {
static void
arena_decay_reinit(arena_t *arena, ssize_t decay_time) {
arena->decay.time = decay_time;
arena_decay_time_write(arena, decay_time);
if (decay_time > 0) {
nstime_init2(&arena->decay.interval, decay_time, 0);
nstime_idivide(&arena->decay.interval, SMOOTHSTEP_NSTEPS);
@ -650,14 +664,8 @@ arena_decay_time_valid(ssize_t decay_time) {
}
ssize_t
arena_decay_time_get(tsdn_t *tsdn, arena_t *arena) {
ssize_t decay_time;
malloc_mutex_lock(tsdn, &arena->decay.mtx);
decay_time = arena->decay.time;
malloc_mutex_unlock(tsdn, &arena->decay.mtx);
return decay_time;
arena_decay_time_get(arena_t *arena) {
return arena_decay_time_read(arena);
}
bool
@ -687,8 +695,9 @@ arena_maybe_purge(tsdn_t *tsdn, arena_t *arena) {
malloc_mutex_assert_owner(tsdn, &arena->decay.mtx);
/* Purge all or nothing if the option is disabled. */
if (arena->decay.time <= 0) {
if (arena->decay.time == 0) {
ssize_t decay_time = arena_decay_time_read(arena);
if (decay_time <= 0) {
if (decay_time == 0) {
arena_purge_to_limit(tsdn, arena, 0);
}
return;

View File

@ -1797,7 +1797,7 @@ arena_i_decay_time_ctl(tsd_t *tsd, const size_t *mib, size_t miblen, void *oldp,
}
if (oldp != NULL && oldlenp != NULL) {
size_t oldval = arena_decay_time_get(tsd_tsdn(tsd), arena);
size_t oldval = arena_decay_time_get(arena);
READ(oldval, ssize_t);
}
if (newp != NULL) {