From bce45ec9fb7bcdd8c306ccc7fc1ecc7f29cecbf5 Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Wed, 24 Jul 2013 10:14:11 -0700 Subject: [PATCH] Make arc+l2arc module options writable The l2arc module options can be made safely writable. This allows the options to be changed without unloading/loading the modules. Signed-off-by: Brian Behlendorf --- module/zfs/arc.c | 109 ++++++++++++++++++++++++++++++------------------------- 1 file changed, 60 insertions(+), 49 deletions(-) diff --git a/module/zfs/arc.c b/module/zfs/arc.c index dca17ab..97c897d 100644 --- a/module/zfs/arc.c +++ b/module/zfs/arc.c @@ -148,7 +148,7 @@ static kcondvar_t arc_reclaim_thr_cv; /* used to signal reclaim thr */ static uint8_t arc_thread_exit; /* number of bytes to prune from caches when at arc_meta_limit is reached */ -uint_t arc_meta_prune = 1048576; +int zfs_arc_meta_prune = 1048576; typedef enum arc_reclaim_strategy { ARC_RECLAIM_AGGR, /* Aggressive reclaim strategy */ @@ -156,25 +156,31 @@ typedef enum arc_reclaim_strategy { } arc_reclaim_strategy_t; /* number of seconds before growing cache again */ -static int arc_grow_retry = 5; - -/* expiration time for arc_no_grow */ -static clock_t arc_grow_time = 0; +int zfs_arc_grow_retry = 5; /* shift of arc_c for calculating both min and max arc_p */ -static int arc_p_min_shift = 4; +int zfs_arc_p_min_shift = 4; /* log2(fraction of arc to reclaim) */ -static int arc_shrink_shift = 5; +int zfs_arc_shrink_shift = 5; /* * minimum lifespan of a prefetch block in clock ticks * (initialized in arc_init()) */ -static int arc_min_prefetch_lifespan; +int zfs_arc_min_prefetch_lifespan = HZ; + +/* disable arc proactive arc throttle due to low memory */ +int zfs_arc_memory_throttle_disable = 1; + +/* disable duplicate buffer eviction */ +int zfs_disable_dup_eviction = 0; static int arc_dead; +/* expiration time for arc_no_grow */ +static clock_t arc_grow_time = 0; + /* * The arc has filled available memory and has now warmed up. */ @@ -186,12 +192,6 @@ static boolean_t arc_warm; unsigned long zfs_arc_max = 0; unsigned long zfs_arc_min = 0; unsigned long zfs_arc_meta_limit = 0; -int zfs_arc_grow_retry = 0; -int zfs_arc_shrink_shift = 0; -int zfs_arc_p_min_shift = 0; -int zfs_arc_memory_throttle_disable = 1; -int zfs_disable_dup_eviction = 0; -int zfs_arc_meta_prune = 0; /* * Note that buffers can be in one of 6 states: @@ -1761,7 +1761,7 @@ arc_evict(arc_state_t *state, uint64_t spa, int64_t bytes, boolean_t recycle, (spa && ab->b_spa != spa) || (ab->b_flags & (ARC_PREFETCH|ARC_INDIRECT) && ddi_get_lbolt() - ab->b_arc_access < - arc_min_prefetch_lifespan)) { + zfs_arc_min_prefetch_lifespan)) { skipped++; continue; } @@ -2112,7 +2112,7 @@ arc_adjust_meta(int64_t adjustment, boolean_t may_prune) } if (may_prune && (adjustment > 0) && (arc_meta_used > arc_meta_limit)) - arc_do_user_prune(arc_meta_prune); + arc_do_user_prune(zfs_arc_meta_prune); } /* @@ -2163,14 +2163,14 @@ arc_shrink(uint64_t bytes) if (arc_c > arc_c_min) { uint64_t to_free; - to_free = bytes ? bytes : arc_c >> arc_shrink_shift; + to_free = bytes ? bytes : arc_c >> zfs_arc_shrink_shift; if (arc_c > arc_c_min + to_free) atomic_add_64(&arc_c, -to_free); else arc_c = arc_c_min; - atomic_add_64(&arc_p, -(arc_p >> arc_shrink_shift)); + atomic_add_64(&arc_p, -(arc_p >> zfs_arc_shrink_shift)); if (arc_c > arc_size) arc_c = MAX(arc_size, arc_c_min); if (arc_p > arc_c) @@ -2249,7 +2249,7 @@ arc_adapt_thread(void) } /* reset the growth delay for every reclaim */ - arc_grow_time = ddi_get_lbolt()+(arc_grow_retry * hz); + arc_grow_time = ddi_get_lbolt()+(zfs_arc_grow_retry * hz); arc_kmem_reap_now(last_reclaim, 0); arc_warm = B_TRUE; @@ -2279,6 +2279,26 @@ arc_adapt_thread(void) (void) cv_timedwait_interruptible(&arc_reclaim_thr_cv, &arc_reclaim_thr_lock, (ddi_get_lbolt() + hz)); CALLB_CPR_SAFE_END(&cpr, &arc_reclaim_thr_lock); + + + /* Allow the module options to be changed */ + if (zfs_arc_max > 64 << 20 && + zfs_arc_max < physmem * PAGESIZE && + zfs_arc_max != arc_c_max) + arc_c_max = zfs_arc_max; + + if (zfs_arc_min > 0 && + zfs_arc_min < arc_c_max && + zfs_arc_min != arc_c_min) + arc_c_min = zfs_arc_min; + + if (zfs_arc_meta_limit > 0 && + zfs_arc_meta_limit <= arc_c_max && + zfs_arc_meta_limit != arc_meta_limit) + arc_meta_limit = zfs_arc_meta_limit; + + + } arc_thread_exit = 0; @@ -2399,7 +2419,7 @@ __arc_shrinker_func(struct shrinker *shrink, struct shrink_control *sc) ARCSTAT_BUMP(arcstat_memory_indirect_count); } else { arc_no_grow = B_TRUE; - arc_grow_time = ddi_get_lbolt() + (arc_grow_retry * hz); + arc_grow_time = ddi_get_lbolt() + (zfs_arc_grow_retry * hz); ARCSTAT_BUMP(arcstat_memory_direct_count); } @@ -2421,7 +2441,7 @@ static void arc_adapt(int bytes, arc_state_t *state) { int mult; - uint64_t arc_p_min = (arc_c >> arc_p_min_shift); + uint64_t arc_p_min = (arc_c >> zfs_arc_p_min_shift); if (state == arc_l2c_only) return; @@ -3756,7 +3776,7 @@ arc_init(void) cv_init(&arc_reclaim_thr_cv, NULL, CV_DEFAULT, NULL); /* Convert seconds to clock ticks */ - arc_min_prefetch_lifespan = 1 * hz; + zfs_arc_min_prefetch_lifespan = 1 * hz; /* Start out with 1/8 of all memory */ arc_c = physmem * PAGESIZE / 8; @@ -3804,18 +3824,6 @@ arc_init(void) if (arc_c_min < arc_meta_limit / 2 && zfs_arc_min == 0) arc_c_min = arc_meta_limit / 2; - if (zfs_arc_grow_retry > 0) - arc_grow_retry = zfs_arc_grow_retry; - - if (zfs_arc_shrink_shift > 0) - arc_shrink_shift = zfs_arc_shrink_shift; - - if (zfs_arc_p_min_shift > 0) - arc_p_min_shift = zfs_arc_p_min_shift; - - if (zfs_arc_meta_prune > 0) - arc_meta_prune = zfs_arc_meta_prune; - /* if kmem_flags are set, lets try to use less memory */ if (kmem_debugging()) arc_c = arc_c / 2; @@ -5013,25 +5021,25 @@ EXPORT_SYMBOL(arc_getbuf_func); EXPORT_SYMBOL(arc_add_prune_callback); EXPORT_SYMBOL(arc_remove_prune_callback); -module_param(zfs_arc_min, ulong, 0444); +module_param(zfs_arc_min, ulong, 0644); MODULE_PARM_DESC(zfs_arc_min, "Min arc size"); -module_param(zfs_arc_max, ulong, 0444); +module_param(zfs_arc_max, ulong, 0644); MODULE_PARM_DESC(zfs_arc_max, "Max arc size"); -module_param(zfs_arc_meta_limit, ulong, 0444); +module_param(zfs_arc_meta_limit, ulong, 0644); MODULE_PARM_DESC(zfs_arc_meta_limit, "Meta limit for arc size"); -module_param(zfs_arc_meta_prune, int, 0444); +module_param(zfs_arc_meta_prune, int, 0644); MODULE_PARM_DESC(zfs_arc_meta_prune, "Bytes of meta data to prune"); -module_param(zfs_arc_grow_retry, int, 0444); +module_param(zfs_arc_grow_retry, int, 0644); MODULE_PARM_DESC(zfs_arc_grow_retry, "Seconds before growing arc size"); -module_param(zfs_arc_shrink_shift, int, 0444); +module_param(zfs_arc_shrink_shift, int, 0644); MODULE_PARM_DESC(zfs_arc_shrink_shift, "log2(fraction of arc to reclaim)"); -module_param(zfs_arc_p_min_shift, int, 0444); +module_param(zfs_arc_p_min_shift, int, 0644); MODULE_PARM_DESC(zfs_arc_p_min_shift, "arc_c shift to calc min/max arc_p"); module_param(zfs_disable_dup_eviction, int, 0644); @@ -5040,28 +5048,31 @@ MODULE_PARM_DESC(zfs_disable_dup_eviction, "disable duplicate buffer eviction"); module_param(zfs_arc_memory_throttle_disable, int, 0644); MODULE_PARM_DESC(zfs_arc_memory_throttle_disable, "disable memory throttle"); -module_param(l2arc_write_max, ulong, 0444); +module_param(zfs_arc_min_prefetch_lifespan, int, 0644); +MODULE_PARM_DESC(zfs_arc_min_prefetch_lifespan, "Min life of prefetch block"); + +module_param(l2arc_write_max, ulong, 0644); MODULE_PARM_DESC(l2arc_write_max, "Max write bytes per interval"); -module_param(l2arc_write_boost, ulong, 0444); +module_param(l2arc_write_boost, ulong, 0644); MODULE_PARM_DESC(l2arc_write_boost, "Extra write bytes during device warmup"); -module_param(l2arc_headroom, ulong, 0444); +module_param(l2arc_headroom, ulong, 0644); MODULE_PARM_DESC(l2arc_headroom, "Number of max device writes to precache"); -module_param(l2arc_feed_secs, ulong, 0444); +module_param(l2arc_feed_secs, ulong, 0644); MODULE_PARM_DESC(l2arc_feed_secs, "Seconds between L2ARC writing"); -module_param(l2arc_feed_min_ms, ulong, 0444); +module_param(l2arc_feed_min_ms, ulong, 0644); MODULE_PARM_DESC(l2arc_feed_min_ms, "Min feed interval in milliseconds"); -module_param(l2arc_noprefetch, int, 0444); +module_param(l2arc_noprefetch, int, 0644); MODULE_PARM_DESC(l2arc_noprefetch, "Skip caching prefetched buffers"); -module_param(l2arc_feed_again, int, 0444); +module_param(l2arc_feed_again, int, 0644); MODULE_PARM_DESC(l2arc_feed_again, "Turbo L2ARC warmup"); -module_param(l2arc_norw, int, 0444); +module_param(l2arc_norw, int, 0644); MODULE_PARM_DESC(l2arc_norw, "No reads during writes"); #endif -- 1.8.3.1