diff options
| -rw-r--r-- | man/man5/zfs-module-parameters.5 | 13 | ||||
| -rw-r--r-- | module/zfs/arc.c | 44 |
2 files changed, 44 insertions, 13 deletions
diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5 index c0365ea5c..de3f35bbb 100644 --- a/man/man5/zfs-module-parameters.5 +++ b/man/man5/zfs-module-parameters.5 @@ -388,23 +388,24 @@ Default value: \fB5\fR. .sp .ne 2 .na -\fBzfs_arc_max\fR (ulong) +\fBzfs_arc_lotsfree_percent\fR (int) .ad .RS 12n -Max arc size +Throttle I/O when free system memory drops below this percentage of total +system memory. Setting this value to 0 will disable the throttle. .sp -Default value: \fB0\fR. +Default value: \fB10\fR. .RE .sp .ne 2 .na -\fBzfs_arc_memory_throttle_disable\fR (int) +\fBzfs_arc_max\fR (ulong) .ad .RS 12n -Disable memory throttle +Max arc size .sp -Use \fB1\fR for yes (default) and \fB0\fR to disable. +Default value: \fB0\fR. .RE .sp diff --git a/module/zfs/arc.c b/module/zfs/arc.c index 97bfb2c25..00d989028 100644 --- a/module/zfs/arc.c +++ b/module/zfs/arc.c @@ -241,13 +241,13 @@ int zfs_arc_average_blocksize = 8 * 1024; /* 8KB */ * These tunables are Linux specific */ unsigned long zfs_arc_sys_free = 0; -int zfs_arc_memory_throttle_disable = 1; int zfs_arc_min_prefetch_lifespan = 0; int zfs_arc_p_aggressive_disable = 1; int zfs_arc_p_dampener_disable = 1; int zfs_arc_meta_prune = 10000; int zfs_arc_meta_strategy = ARC_STRATEGY_META_BALANCED; int zfs_arc_meta_adjust_restarts = 4096; +int zfs_arc_lotsfree_percent = 10; /* The 6 states: */ static arc_state_t ARC_anon; @@ -5064,18 +5064,41 @@ static int arc_memory_throttle(uint64_t reserve, uint64_t txg) { #ifdef _KERNEL - if (zfs_arc_memory_throttle_disable) - return (0); + uint64_t available_memory = ptob(freemem); + static uint64_t page_load = 0; + static uint64_t last_txg = 0; +#ifdef __linux__ + pgcnt_t minfree = btop(arc_sys_free / 4); +#endif if (freemem > physmem * arc_lotsfree_percent / 100) return (0); - if (arc_reclaim_needed()) { + if (txg > last_txg) { + last_txg = txg; + page_load = 0; + } + + /* + * If we are in pageout, we know that memory is already tight, + * the arc is already going to be evicting, so we just want to + * continue to let page writes occur as quickly as possible. + */ + if (current_is_kswapd()) { + if (page_load > MAX(ptob(minfree), available_memory) / 4) { + DMU_TX_STAT_BUMP(dmu_tx_memory_reclaim); + return (SET_ERROR(ERESTART)); + } + /* Note: reserve is inflated, so we deflate */ + page_load += reserve / 8; + return (0); + } else if (page_load > 0 && arc_reclaim_needed()) { /* memory is low, delay before restarting */ ARCSTAT_INCR(arcstat_memory_throttle_count, 1); DMU_TX_STAT_BUMP(dmu_tx_memory_reclaim); return (SET_ERROR(EAGAIN)); } + page_load = 0; #endif return (0); } @@ -5280,9 +5303,15 @@ arc_tuning_update(void) if (zfs_arc_min_prefetch_lifespan) arc_min_prefetch_lifespan = zfs_arc_min_prefetch_lifespan; + /* Valid range: 0 - 100 */ + if ((zfs_arc_lotsfree_percent >= 0) && + (zfs_arc_lotsfree_percent <= 100)) + arc_lotsfree_percent = zfs_arc_lotsfree_percent; + /* Valid range: 0 - <all physical memory> */ if ((zfs_arc_sys_free) && (zfs_arc_sys_free != arc_sys_free)) arc_sys_free = MIN(MAX(zfs_arc_sys_free, 0), ptob(physmem)); + } void @@ -7023,9 +7052,6 @@ MODULE_PARM_DESC(zfs_disable_dup_eviction, "disable duplicate buffer eviction"); module_param(zfs_arc_average_blocksize, int, 0444); MODULE_PARM_DESC(zfs_arc_average_blocksize, "Target average block size"); -module_param(zfs_arc_memory_throttle_disable, int, 0644); -MODULE_PARM_DESC(zfs_arc_memory_throttle_disable, "disable memory throttle"); - module_param(zfs_arc_min_prefetch_lifespan, int, 0644); MODULE_PARM_DESC(zfs_arc_min_prefetch_lifespan, "Min life of prefetch block"); @@ -7063,6 +7089,10 @@ MODULE_PARM_DESC(l2arc_feed_again, "Turbo L2ARC warmup"); module_param(l2arc_norw, int, 0644); MODULE_PARM_DESC(l2arc_norw, "No reads during writes"); +module_param(zfs_arc_lotsfree_percent, int, 0644); +MODULE_PARM_DESC(zfs_arc_lotsfree_percent, + "System free memory I/O throttle in bytes"); + module_param(zfs_arc_sys_free, ulong, 0644); MODULE_PARM_DESC(zfs_arc_sys_free, "System free memory target size in bytes"); |