Date: Thu, 25 Apr 2019 14:41:29 +0000 (UTC) From: Alexander Motin <mav@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r346674 - in stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs: . sys Message-ID: <201904251441.x3PEfTiP056709@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: mav Date: Thu Apr 25 14:41:29 2019 New Revision: 346674 URL: https://svnweb.freebsd.org/changeset/base/346674 Log: MFC r345200: MFV r336930: 9284 arc_reclaim_thread has 2 jobs `arc_reclaim_thread()` calls `arc_adjust()` after calling `arc_kmem_reap_now()`; `arc_adjust()` signals `arc_get_data_buf()` to indicate that we may no longer be `arc_is_overflowing()`. The problem is, `arc_kmem_reap_now()` can take several seconds to complete, has no impact on `arc_is_overflowing()`, but due to how the code is structured, can impact how long the ARC will remain in the `arc_is_overflowing()` state. The fix is to use seperate threads to: 1. keep `arc_size` under `arc_c`, by calling `arc_adjust()`, which improves `arc_is_overflowing()` 2. keep enough free memory in the system, by calling `arc_kmem_reap_now()` plus `arc_shrink()`, which improves `arc_available_memory()`. illumos/illumos-gate@de753e34f9c399037936e8bc547d823bba9d4b0d Reviewed by: Matt Ahrens <mahrens@delphix.com> Reviewed by: Serapheim Dimitropoulos <serapheim@delphix.com> Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com> Reviewed by: Dan Kimmel <dan.kimmel@delphix.com> Reviewed by: Paul Dagnelie <pcd@delphix.com> Reviewed by: Dan McDonald <danmcd@joyent.com> Reviewed by: Tim Kordas <tim.kordas@joyent.com> Approved by: Garrett D'Amore <garrett@damore.org> Modified: stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zthr.h stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zthr.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c ============================================================================== --- stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Thu Apr 25 14:39:52 2019 (r346673) +++ stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Thu Apr 25 14:41:29 2019 (r346674) @@ -281,6 +281,7 @@ #include <sys/callb.h> #include <sys/kstat.h> #include <sys/trim_map.h> +#include <sys/zthr.h> #include <zfs_fletcher.h> #include <sys/sdt.h> #include <sys/aggsum.h> @@ -296,11 +297,23 @@ int arc_procfd; #endif #endif /* illumos */ -static kmutex_t arc_reclaim_lock; -static kcondvar_t arc_reclaim_thread_cv; -static boolean_t arc_reclaim_thread_exit; -static kcondvar_t arc_reclaim_waiters_cv; +/* + * This thread's job is to keep enough free memory in the system, by + * calling arc_kmem_reap_now() plus arc_shrink(), which improves + * arc_available_memory(). + */ +static zthr_t *arc_reap_zthr; +/* + * This thread's job is to keep arc_size under arc_c, by calling + * arc_adjust(), which improves arc_is_overflowing(). + */ +static zthr_t *arc_adjust_zthr; + +static kmutex_t arc_adjust_lock; +static kcondvar_t arc_adjust_waiters_cv; +static boolean_t arc_adjust_needed = B_FALSE; + static kmutex_t arc_dnlc_evicts_lock; static kcondvar_t arc_dnlc_evicts_cv; static boolean_t arc_dnlc_evicts_thread_exit; @@ -317,19 +330,23 @@ uint_t arc_reduce_dnlc_percent = 3; int zfs_arc_evict_batch_limit = 10; /* number of seconds before growing cache again */ -static int arc_grow_retry = 60; +int arc_grow_retry = 60; -/* number of milliseconds before attempting a kmem-cache-reap */ -static int arc_kmem_cache_reap_retry_ms = 0; +/* + * Minimum time between calls to arc_kmem_reap_soon(). Note that this will + * be converted to ticks, so with the default hz=100, a setting of 15 ms + * will actually wait 2 ticks, or 20ms. + */ +int arc_kmem_cache_reap_retry_ms = 1000; /* shift of arc_c for calculating overflow limit in arc_get_data_impl */ -int zfs_arc_overflow_shift = 8; +int zfs_arc_overflow_shift = 8; /* shift of arc_c for calculating both min and max arc_p */ -static int arc_p_min_shift = 4; +int arc_p_min_shift = 4; /* log2(fraction of arc to reclaim) */ -static int arc_shrink_shift = 7; +int arc_shrink_shift = 7; /* * log2(fraction of ARC which must be free to allow growing). @@ -355,7 +372,7 @@ static int zfs_arc_min_prescient_prefetch_ms = 6; */ int arc_lotsfree_percent = 10; -static int arc_dead; +static boolean_t arc_initialized; extern boolean_t zfs_prefetch_disable; /* @@ -1052,6 +1069,7 @@ static kmutex_t arc_prune_mtx; static taskq_t *arc_prune_taskq; static int arc_no_grow; /* Don't try to grow cache size */ +static hrtime_t arc_growtime; static uint64_t arc_tempreserve; static uint64_t arc_loaned_bytes; @@ -1819,8 +1837,8 @@ hdr_recl(void *unused) * umem calls the reclaim func when we destroy the buf cache, * which is after we do arc_fini(). */ - if (!arc_dead) - cv_signal(&arc_reclaim_thread_cv); + if (arc_initialized) + zthr_wakeup(arc_reap_zthr); } static void @@ -3905,13 +3923,14 @@ arc_evict_state_impl(multilist_t *ml, int idx, arc_buf * function should proceed in this case). * * If threads are left sleeping, due to not - * using cv_broadcast, they will be woken up - * just before arc_reclaim_thread() sleeps. + * using cv_broadcast here, they will be woken + * up via cv_broadcast in arc_adjust_cb() just + * before arc_adjust_zthr sleeps. */ - mutex_enter(&arc_reclaim_lock); + mutex_enter(&arc_adjust_lock); if (!arc_is_overflowing()) - cv_signal(&arc_reclaim_waiters_cv); - mutex_exit(&arc_reclaim_lock); + cv_signal(&arc_adjust_waiters_cv); + mutex_exit(&arc_adjust_lock); } else { ARCSTAT_BUMP(arcstat_mutex_miss); } @@ -4565,8 +4584,8 @@ arc_flush(spa_t *spa, boolean_t retry) (void) arc_flush_state(arc_mfu_ghost, guid, ARC_BUFC_METADATA, retry); } -uint64_t -arc_shrink(int64_t to_free) +static void +arc_reduce_target_size(int64_t to_free) { uint64_t asize = aggsum_value(&arc_size); if (arc_c > arc_c_min) { @@ -4593,9 +4612,12 @@ arc_shrink(int64_t to_free) if (asize > arc_c) { DTRACE_PROBE2(arc__shrink_adjust, uint64_t, asize, uint64_t, arc_c); - return (arc_adjust()); + /* See comment in arc_adjust_cb_check() on why lock+flag */ + mutex_enter(&arc_adjust_lock); + arc_adjust_needed = B_TRUE; + mutex_exit(&arc_adjust_lock); + zthr_wakeup(arc_adjust_zthr); } - return (0); } typedef enum free_memory_reason_t { @@ -4765,7 +4787,7 @@ extern kmem_cache_t *range_seg_cache; extern kmem_cache_t *abd_chunk_cache; static __noinline void -arc_kmem_reap_now(void) +arc_kmem_reap_soon(void) { size_t i; kmem_cache_t *prev_cache = NULL; @@ -4788,16 +4810,6 @@ arc_kmem_reap_now(void) #endif #endif - /* - * If a kmem reap is already active, don't schedule more. We must - * check for this because kmem_cache_reap_soon() won't actually - * block on the cache being reaped (this is to prevent callers from - * becoming implicitly blocked by a system-wide kmem reap -- which, - * on a system with many, many full magazines, can take minutes). - */ - if (kmem_cache_reap_active()) - return; - for (i = 0; i < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; i++) { if (zio_buf_cache[i] != prev_cache) { prev_cache = zio_buf_cache[i]; @@ -4826,141 +4838,163 @@ arc_kmem_reap_now(void) DTRACE_PROBE(arc__kmem_reap_end); } -/* - * Threads can block in arc_get_data_impl() waiting for this thread to evict - * enough data and signal them to proceed. When this happens, the threads in - * arc_get_data_impl() are sleeping while holding the hash lock for their - * particular arc header. Thus, we must be careful to never sleep on a - * hash lock in this thread. This is to prevent the following deadlock: - * - * - Thread A sleeps on CV in arc_get_data_impl() holding hash lock "L", - * waiting for the reclaim thread to signal it. - * - * - arc_reclaim_thread() tries to acquire hash lock "L" using mutex_enter, - * fails, and goes to sleep forever. - * - * This possible deadlock is avoided by always acquiring a hash lock - * using mutex_tryenter() from arc_reclaim_thread(). - */ /* ARGSUSED */ -static void -arc_reclaim_thread(void *unused __unused) +static boolean_t +arc_adjust_cb_check(void *arg, zthr_t *zthr) { - hrtime_t growtime = 0; - hrtime_t kmem_reap_time = 0; - callb_cpr_t cpr; + /* + * This is necessary in order for the mdb ::arc dcmd to + * show up to date information. Since the ::arc command + * does not call the kstat's update function, without + * this call, the command may show stale stats for the + * anon, mru, mru_ghost, mfu, and mfu_ghost lists. Even + * with this change, the data might be up to 1 second + * out of date(the arc_adjust_zthr has a maximum sleep + * time of 1 second); but that should suffice. The + * arc_state_t structures can be queried directly if more + * accurate information is needed. + */ + if (arc_ksp != NULL) + arc_ksp->ks_update(arc_ksp, KSTAT_READ); - CALLB_CPR_INIT(&cpr, &arc_reclaim_lock, callb_generic_cpr, FTAG); + /* + * We have to rely on arc_get_data_impl() to tell us when to adjust, + * rather than checking if we are overflowing here, so that we are + * sure to not leave arc_get_data_impl() waiting on + * arc_adjust_waiters_cv. If we have become "not overflowing" since + * arc_get_data_impl() checked, we need to wake it up. We could + * broadcast the CV here, but arc_get_data_impl() may have not yet + * gone to sleep. We would need to use a mutex to ensure that this + * function doesn't broadcast until arc_get_data_impl() has gone to + * sleep (e.g. the arc_adjust_lock). However, the lock ordering of + * such a lock would necessarily be incorrect with respect to the + * zthr_lock, which is held before this function is called, and is + * held by arc_get_data_impl() when it calls zthr_wakeup(). + */ + return (arc_adjust_needed); +} - mutex_enter(&arc_reclaim_lock); - while (!arc_reclaim_thread_exit) { - uint64_t evicted = 0; +/* + * Keep arc_size under arc_c by running arc_adjust which evicts data + * from the ARC. */ +/* ARGSUSED */ +static int +arc_adjust_cb(void *arg, zthr_t *zthr) +{ + uint64_t evicted = 0; + /* Evict from cache */ + evicted = arc_adjust(); + + /* + * If evicted is zero, we couldn't evict anything + * via arc_adjust(). This could be due to hash lock + * collisions, but more likely due to the majority of + * arc buffers being unevictable. Therefore, even if + * arc_size is above arc_c, another pass is unlikely to + * be helpful and could potentially cause us to enter an + * infinite loop. Additionally, zthr_iscancelled() is + * checked here so that if the arc is shutting down, the + * broadcast will wake any remaining arc adjust waiters. + */ + mutex_enter(&arc_adjust_lock); + arc_adjust_needed = !zthr_iscancelled(arc_adjust_zthr) && + evicted > 0 && aggsum_compare(&arc_size, arc_c) > 0; + if (!arc_adjust_needed) { /* - * This is necessary in order for the mdb ::arc dcmd to - * show up to date information. Since the ::arc command - * does not call the kstat's update function, without - * this call, the command may show stale stats for the - * anon, mru, mru_ghost, mfu, and mfu_ghost lists. Even - * with this change, the data might be up to 1 second - * out of date; but that should suffice. The arc_state_t - * structures can be queried directly if more accurate - * information is needed. + * We're either no longer overflowing, or we + * can't evict anything more, so we should wake + * up any waiters. */ - if (arc_ksp != NULL) - arc_ksp->ks_update(arc_ksp, KSTAT_READ); + cv_broadcast(&arc_adjust_waiters_cv); + } + mutex_exit(&arc_adjust_lock); - mutex_exit(&arc_reclaim_lock); + return (0); +} +/* ARGSUSED */ +static boolean_t +arc_reap_cb_check(void *arg, zthr_t *zthr) +{ + int64_t free_memory = arc_available_memory(); + + /* + * If a kmem reap is already active, don't schedule more. We must + * check for this because kmem_cache_reap_soon() won't actually + * block on the cache being reaped (this is to prevent callers from + * becoming implicitly blocked by a system-wide kmem reap -- which, + * on a system with many, many full magazines, can take minutes). + */ + if (!kmem_cache_reap_active() && + free_memory < 0) { + arc_no_grow = B_TRUE; + arc_warm = B_TRUE; /* - * We call arc_adjust() before (possibly) calling - * arc_kmem_reap_now(), so that we can wake up - * arc_get_data_impl() sooner. + * Wait at least zfs_grow_retry (default 60) seconds + * before considering growing. */ - evicted = arc_adjust(); + arc_growtime = gethrtime() + SEC2NSEC(arc_grow_retry); + return (B_TRUE); + } else if (free_memory < arc_c >> arc_no_grow_shift) { + arc_no_grow = B_TRUE; + } else if (gethrtime() >= arc_growtime) { + arc_no_grow = B_FALSE; + } - int64_t free_memory = arc_available_memory(); - if (free_memory < 0) { - hrtime_t curtime = gethrtime(); - arc_no_grow = B_TRUE; - arc_warm = B_TRUE; + return (B_FALSE); +} - /* - * Wait at least zfs_grow_retry (default 60) seconds - * before considering growing. - */ - growtime = curtime + SEC2NSEC(arc_grow_retry); +/* + * Keep enough free memory in the system by reaping the ARC's kmem + * caches. To cause more slabs to be reapable, we may reduce the + * target size of the cache (arc_c), causing the arc_adjust_cb() + * to free more buffers. + */ +/* ARGSUSED */ +static int +arc_reap_cb(void *arg, zthr_t *zthr) +{ + int64_t free_memory; - /* - * Wait at least arc_kmem_cache_reap_retry_ms - * between arc_kmem_reap_now() calls. Without - * this check it is possible to end up in a - * situation where we spend lots of time - * reaping caches, while we're near arc_c_min. - */ - if (curtime >= kmem_reap_time) { - arc_kmem_reap_now(); - kmem_reap_time = gethrtime() + - MSEC2NSEC(arc_kmem_cache_reap_retry_ms); - } + /* + * Kick off asynchronous kmem_reap()'s of all our caches. + */ + arc_kmem_reap_soon(); - /* - * If we are still low on memory, shrink the ARC - * so that we have arc_shrink_min free space. - */ - free_memory = arc_available_memory(); + /* + * Wait at least arc_kmem_cache_reap_retry_ms between + * arc_kmem_reap_soon() calls. Without this check it is possible to + * end up in a situation where we spend lots of time reaping + * caches, while we're near arc_c_min. Waiting here also gives the + * subsequent free memory check a chance of finding that the + * asynchronous reap has already freed enough memory, and we don't + * need to call arc_reduce_target_size(). + */ + delay((hz * arc_kmem_cache_reap_retry_ms + 999) / 1000); - int64_t to_free = - (arc_c >> arc_shrink_shift) - free_memory; - if (to_free > 0) { + /* + * Reduce the target size as needed to maintain the amount of free + * memory in the system at a fraction of the arc_size (1/128th by + * default). If oversubscribed (free_memory < 0) then reduce the + * target arc_size by the deficit amount plus the fractional + * amount. If free memory is positive but less then the fractional + * amount, reduce by what is needed to hit the fractional amount. + */ + free_memory = arc_available_memory(); + + int64_t to_free = + (arc_c >> arc_shrink_shift) - free_memory; + if (to_free > 0) { #ifdef _KERNEL #ifdef illumos - to_free = MAX(to_free, ptob(needfree)); + to_free = MAX(to_free, ptob(needfree)); #endif #endif - evicted += arc_shrink(to_free); - } - } else if (free_memory < arc_c >> arc_no_grow_shift) { - arc_no_grow = B_TRUE; - } else if (gethrtime() >= growtime) { - arc_no_grow = B_FALSE; - } - - mutex_enter(&arc_reclaim_lock); - - /* - * If evicted is zero, we couldn't evict anything via - * arc_adjust(). This could be due to hash lock - * collisions, but more likely due to the majority of - * arc buffers being unevictable. Therefore, even if - * arc_size is above arc_c, another pass is unlikely to - * be helpful and could potentially cause us to enter an - * infinite loop. - */ - if (aggsum_compare(&arc_size, arc_c) <= 0|| evicted == 0) { - /* - * We're either no longer overflowing, or we - * can't evict anything more, so we should wake - * up any threads before we go to sleep. - */ - cv_broadcast(&arc_reclaim_waiters_cv); - - /* - * Block until signaled, or after one second (we - * might need to perform arc_kmem_reap_now() - * even if we aren't being signalled) - */ - CALLB_CPR_SAFE_BEGIN(&cpr); - (void) cv_timedwait_hires(&arc_reclaim_thread_cv, - &arc_reclaim_lock, SEC2NSEC(1), MSEC2NSEC(1), 0); - CALLB_CPR_SAFE_END(&cpr, &arc_reclaim_lock); - } + arc_reduce_target_size(to_free); } - arc_reclaim_thread_exit = B_FALSE; - cv_broadcast(&arc_reclaim_thread_cv); - CALLB_CPR_EXIT(&cpr); /* drops arc_reclaim_lock */ - thread_exit(); + return (0); } static u_int arc_dnlc_evicts_arg; @@ -5055,8 +5089,11 @@ arc_adapt(int bytes, arc_state_t *state) } ASSERT((int64_t)arc_p >= 0); + /* + * Wake reap thread if we do not have any available memory + */ if (arc_reclaim_needed()) { - cv_signal(&arc_reclaim_thread_cv); + zthr_wakeup(arc_reap_zthr); return; } @@ -5164,7 +5201,7 @@ arc_get_data_impl(arc_buf_hdr_t *hdr, uint64_t size, v * overflowing; thus we don't use a while loop here. */ if (arc_is_overflowing()) { - mutex_enter(&arc_reclaim_lock); + mutex_enter(&arc_adjust_lock); /* * Now that we've acquired the lock, we may no longer be @@ -5178,11 +5215,12 @@ arc_get_data_impl(arc_buf_hdr_t *hdr, uint64_t size, v * shouldn't cause any harm. */ if (arc_is_overflowing()) { - cv_signal(&arc_reclaim_thread_cv); - cv_wait(&arc_reclaim_waiters_cv, &arc_reclaim_lock); + arc_adjust_needed = B_TRUE; + zthr_wakeup(arc_adjust_zthr); + (void) cv_wait(&arc_adjust_waiters_cv, + &arc_adjust_lock); } - - mutex_exit(&arc_reclaim_lock); + mutex_exit(&arc_adjust_lock); } VERIFY3U(hdr->b_type, ==, type); @@ -6898,19 +6936,28 @@ static eventhandler_tag arc_event_lowmem = NULL; static void arc_lowmem(void *arg __unused, int howto __unused) { + int64_t free_memory, to_free; - mutex_enter(&arc_reclaim_lock); - DTRACE_PROBE1(arc__needfree, int64_t, ((int64_t)freemem - zfs_arc_free_target) * PAGESIZE); - cv_signal(&arc_reclaim_thread_cv); + arc_no_grow = B_TRUE; + arc_warm = B_TRUE; + arc_growtime = gethrtime() + SEC2NSEC(arc_grow_retry); + free_memory = arc_available_memory(); + to_free = (arc_c >> arc_shrink_shift) - MIN(free_memory, 0); + DTRACE_PROBE2(arc__needfree, int64_t, free_memory, int64_t, to_free); + arc_reduce_target_size(to_free); + mutex_enter(&arc_adjust_lock); + arc_adjust_needed = B_TRUE; + zthr_wakeup(arc_adjust_zthr); + /* * It is unsafe to block here in arbitrary threads, because we can come * here from ARC itself and may hold ARC locks and thus risk a deadlock * with ARC reclaim thread. */ if (curproc == pageproc) - (void) cv_wait(&arc_reclaim_waiters_cv, &arc_reclaim_lock); - mutex_exit(&arc_reclaim_lock); + (void) cv_wait(&arc_adjust_waiters_cv, &arc_adjust_lock); + mutex_exit(&arc_adjust_lock); } #endif @@ -7052,12 +7099,9 @@ arc_init(void) #else uint64_t allmem = kmem_size(); #endif + mutex_init(&arc_adjust_lock, NULL, MUTEX_DEFAULT, NULL); + cv_init(&arc_adjust_waiters_cv, NULL, CV_DEFAULT, NULL); - - mutex_init(&arc_reclaim_lock, NULL, MUTEX_DEFAULT, NULL); - cv_init(&arc_reclaim_thread_cv, NULL, CV_DEFAULT, NULL); - cv_init(&arc_reclaim_waiters_cv, NULL, CV_DEFAULT, NULL); - mutex_init(&arc_dnlc_evicts_lock, NULL, MUTEX_DEFAULT, NULL); cv_init(&arc_dnlc_evicts_cv, NULL, CV_DEFAULT, NULL); @@ -7159,6 +7203,13 @@ arc_init(void) zfs_arc_max = arc_c_max; arc_state_init(); + + /* + * The arc must be "uninitialized", so that hdr_recl() (which is + * registered by buf_init()) will not access arc_reap_zthr before + * it is created. + */ + ASSERT(!arc_initialized); buf_init(); list_create(&arc_prune_list, sizeof (arc_prune_t), @@ -7168,7 +7219,6 @@ arc_init(void) arc_prune_taskq = taskq_create("arc_prune", max_ncpus, minclsyspri, max_ncpus, INT_MAX, TASKQ_PREPOPULATE | TASKQ_DYNAMIC); - arc_reclaim_thread_exit = B_FALSE; arc_dnlc_evicts_thread_exit = FALSE; arc_ksp = kstat_create("zfs", 0, "arcstats", "misc", KSTAT_TYPE_NAMED, @@ -7180,8 +7230,10 @@ arc_init(void) kstat_install(arc_ksp); } - (void) thread_create(NULL, 0, arc_reclaim_thread, NULL, 0, &p0, - TS_RUN, minclsyspri); + arc_adjust_zthr = zthr_create_timer(arc_adjust_cb_check, + arc_adjust_cb, NULL, SEC2NSEC(1)); + arc_reap_zthr = zthr_create_timer(arc_reap_cb_check, + arc_reap_cb, NULL, SEC2NSEC(1)); #ifdef _KERNEL arc_event_lowmem = EVENTHANDLER_REGISTER(vm_lowmem, arc_lowmem, NULL, @@ -7191,7 +7243,7 @@ arc_init(void) (void) thread_create(NULL, 0, arc_dnlc_evicts_thread, NULL, 0, &p0, TS_RUN, minclsyspri); - arc_dead = B_FALSE; + arc_initialized = B_TRUE; arc_warm = B_FALSE; /* @@ -7256,18 +7308,6 @@ arc_fini(void) EVENTHANDLER_DEREGISTER(vm_lowmem, arc_event_lowmem); #endif - mutex_enter(&arc_reclaim_lock); - arc_reclaim_thread_exit = B_TRUE; - /* - * The reclaim thread will set arc_reclaim_thread_exit back to - * B_FALSE when it is finished exiting; we're waiting for that. - */ - while (arc_reclaim_thread_exit) { - cv_signal(&arc_reclaim_thread_cv); - cv_wait(&arc_reclaim_thread_cv, &arc_reclaim_lock); - } - mutex_exit(&arc_reclaim_lock); - /* Use B_TRUE to ensure *all* buffers are evicted */ arc_flush(NULL, B_TRUE); @@ -7283,7 +7323,7 @@ arc_fini(void) } mutex_exit(&arc_dnlc_evicts_lock); - arc_dead = B_TRUE; + arc_initialized = B_FALSE; if (arc_ksp != NULL) { kstat_delete(arc_ksp); @@ -7304,12 +7344,18 @@ arc_fini(void) list_destroy(&arc_prune_list); mutex_destroy(&arc_prune_mtx); - mutex_destroy(&arc_reclaim_lock); - cv_destroy(&arc_reclaim_thread_cv); - cv_destroy(&arc_reclaim_waiters_cv); + (void) zthr_cancel(arc_adjust_zthr); + zthr_destroy(arc_adjust_zthr); + mutex_destroy(&arc_dnlc_evicts_lock); cv_destroy(&arc_dnlc_evicts_cv); + + (void) zthr_cancel(arc_reap_zthr); + zthr_destroy(arc_reap_zthr); + + mutex_destroy(&arc_adjust_lock); + cv_destroy(&arc_adjust_waiters_cv); arc_state_fini(); buf_fini(); Modified: stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zthr.h ============================================================================== --- stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zthr.h Thu Apr 25 14:39:52 2019 (r346673) +++ stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zthr.h Thu Apr 25 14:41:29 2019 (r346674) @@ -29,6 +29,7 @@ struct zthr { kmutex_t zthr_lock; kcondvar_t zthr_cv; boolean_t zthr_cancel; + hrtime_t zthr_wait_time; zthr_checkfunc_t *zthr_checkfunc; zthr_func_t *zthr_func; @@ -38,6 +39,9 @@ struct zthr { extern zthr_t *zthr_create(zthr_checkfunc_t checkfunc, zthr_func_t *func, void *arg); +extern zthr_t *zthr_create_timer(zthr_checkfunc_t *checkfunc, + zthr_func_t *func, void *arg, hrtime_t nano_wait); + extern void zthr_exit(zthr_t *t, int rc); extern void zthr_destroy(zthr_t *t); Modified: stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zthr.c ============================================================================== --- stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zthr.c Thu Apr 25 14:39:52 2019 (r346673) +++ stable/12/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zthr.c Thu Apr 25 14:41:29 2019 (r346674) @@ -47,6 +47,10 @@ * 3] When the zthr is done, it changes the indicator to stopped, allowing * a new cycle to start. * + * Besides being awakened by other threads, a zthr can be configured + * during creation to wakeup on it's own after a specified interval + * [see zthr_create_timer()]. + * * == ZTHR creation * * Every zthr needs three inputs to start running: @@ -74,6 +78,9 @@ * * To start a zthr: * zthr_t *zthr_pointer = zthr_create(checkfunc, func, args); + * or + * zthr_t *zthr_pointer = zthr_create_timer(checkfunc, func, + * args, max_sleep); * * After that you should be able to wakeup, cancel, and resume the * zthr from another thread using zthr_pointer. @@ -189,7 +196,13 @@ zthr_procedure(void *arg) mutex_enter(&t->zthr_lock); } else { /* go to sleep */ - cv_wait(&t->zthr_cv, &t->zthr_lock); + if (t->zthr_wait_time == 0) { + cv_wait(&t->zthr_cv, &t->zthr_lock); + } else { + (void) cv_timedwait_hires(&t->zthr_cv, + &t->zthr_lock, t->zthr_wait_time, + MSEC2NSEC(1), 0); + } } } mutex_exit(&t->zthr_lock); @@ -200,6 +213,18 @@ zthr_procedure(void *arg) zthr_t * zthr_create(zthr_checkfunc_t *checkfunc, zthr_func_t *func, void *arg) { + return (zthr_create_timer(checkfunc, func, arg, (hrtime_t)0)); +} + +/* + * Create a zthr with specified maximum sleep time. If the time + * in sleeping state exceeds max_sleep, a wakeup(do the check and + * start working if required) will be triggered. + */ +zthr_t * +zthr_create_timer(zthr_checkfunc_t *checkfunc, zthr_func_t *func, + void *arg, hrtime_t max_sleep) +{ zthr_t *t = kmem_zalloc(sizeof (*t), KM_SLEEP); mutex_init(&t->zthr_lock, NULL, MUTEX_DEFAULT, NULL); cv_init(&t->zthr_cv, NULL, CV_DEFAULT, NULL); @@ -208,6 +233,7 @@ zthr_create(zthr_checkfunc_t *checkfunc, zthr_func_t * t->zthr_checkfunc = checkfunc; t->zthr_func = func; t->zthr_arg = arg; + t->zthr_wait_time = max_sleep; t->zthr_thread = thread_create(NULL, 0, zthr_procedure, t, 0, &p0, TS_RUN, minclsyspri);
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201904251441.x3PEfTiP056709>