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@de753e34f9 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> Author: Brad Lewis <brad.lewis@delphix.com>
This commit is contained in:
parent
a622bac50f
commit
ec66f8a6e3
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/vendor-sys/illumos/dist/; revision=336930
@ -274,6 +274,7 @@
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#endif
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#include <sys/callb.h>
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#include <sys/kstat.h>
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#include <sys/zthr.h>
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#include <zfs_fletcher.h>
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#include <sys/aggsum.h>
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#include <sys/cityhash.h>
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@ -284,10 +285,22 @@ boolean_t arc_watch = B_FALSE;
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int arc_procfd;
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#endif
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static kmutex_t arc_reclaim_lock;
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static kcondvar_t arc_reclaim_thread_cv;
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static boolean_t arc_reclaim_thread_exit;
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static kcondvar_t arc_reclaim_waiters_cv;
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/*
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* This thread's job is to keep enough free memory in the system, by
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* calling arc_kmem_reap_now() plus arc_shrink(), which improves
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* arc_available_memory().
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*/
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static zthr_t *arc_reap_zthr;
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/*
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* This thread's job is to keep arc_size under arc_c, by calling
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* arc_adjust(), which improves arc_is_overflowing().
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*/
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static zthr_t *arc_adjust_zthr;
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static kmutex_t arc_adjust_lock;
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static kcondvar_t arc_adjust_waiters_cv;
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static boolean_t arc_adjust_needed = B_FALSE;
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uint_t arc_reduce_dnlc_percent = 3;
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@ -301,19 +314,23 @@ uint_t arc_reduce_dnlc_percent = 3;
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int zfs_arc_evict_batch_limit = 10;
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/* number of seconds before growing cache again */
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static int arc_grow_retry = 60;
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int arc_grow_retry = 60;
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/* number of milliseconds before attempting a kmem-cache-reap */
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static int arc_kmem_cache_reap_retry_ms = 1000;
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/*
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* Minimum time between calls to arc_kmem_reap_soon(). Note that this will
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* be converted to ticks, so with the default hz=100, a setting of 15 ms
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* will actually wait 2 ticks, or 20ms.
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*/
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int arc_kmem_cache_reap_retry_ms = 1000;
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/* shift of arc_c for calculating overflow limit in arc_get_data_impl */
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int zfs_arc_overflow_shift = 8;
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int zfs_arc_overflow_shift = 8;
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/* shift of arc_c for calculating both min and max arc_p */
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static int arc_p_min_shift = 4;
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int arc_p_min_shift = 4;
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/* log2(fraction of arc to reclaim) */
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static int arc_shrink_shift = 7;
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int arc_shrink_shift = 7;
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/*
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* log2(fraction of ARC which must be free to allow growing).
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@ -338,7 +355,7 @@ static int arc_min_prefetch_lifespan;
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*/
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int arc_lotsfree_percent = 10;
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static int arc_dead;
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static boolean_t arc_initialized;
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/*
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* The arc has filled available memory and has now warmed up.
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@ -840,6 +857,7 @@ aggsum_t astat_other_size;
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aggsum_t astat_l2_hdr_size;
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static int arc_no_grow; /* Don't try to grow cache size */
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static hrtime_t arc_growtime;
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static uint64_t arc_tempreserve;
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static uint64_t arc_loaned_bytes;
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@ -1399,8 +1417,8 @@ hdr_recl(void *unused)
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* umem calls the reclaim func when we destroy the buf cache,
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* which is after we do arc_fini().
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*/
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if (!arc_dead)
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cv_signal(&arc_reclaim_thread_cv);
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if (arc_initialized)
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zthr_wakeup(arc_reap_zthr);
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}
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static void
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@ -3413,13 +3431,14 @@ arc_evict_state_impl(multilist_t *ml, int idx, arc_buf_hdr_t *marker,
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* function should proceed in this case).
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*
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* If threads are left sleeping, due to not
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* using cv_broadcast, they will be woken up
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* just before arc_reclaim_thread() sleeps.
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* using cv_broadcast here, they will be woken
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* up via cv_broadcast in arc_adjust_cb() just
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* before arc_adjust_zthr sleeps.
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*/
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mutex_enter(&arc_reclaim_lock);
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mutex_enter(&arc_adjust_lock);
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if (!arc_is_overflowing())
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cv_signal(&arc_reclaim_waiters_cv);
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mutex_exit(&arc_reclaim_lock);
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cv_signal(&arc_adjust_waiters_cv);
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mutex_exit(&arc_adjust_lock);
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} else {
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ARCSTAT_BUMP(arcstat_mutex_miss);
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}
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@ -3892,8 +3911,8 @@ arc_flush(spa_t *spa, boolean_t retry)
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(void) arc_flush_state(arc_mfu_ghost, guid, ARC_BUFC_METADATA, retry);
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}
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void
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arc_shrink(int64_t to_free)
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static void
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arc_reduce_target_size(int64_t to_free)
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{
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uint64_t asize = aggsum_value(&arc_size);
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if (arc_c > arc_c_min) {
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@ -3912,8 +3931,13 @@ arc_shrink(int64_t to_free)
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ASSERT((int64_t)arc_p >= 0);
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}
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if (asize > arc_c)
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(void) arc_adjust();
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if (asize > arc_c) {
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/* See comment in arc_adjust_cb_check() on why lock+flag */
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mutex_enter(&arc_adjust_lock);
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arc_adjust_needed = B_TRUE;
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mutex_exit(&arc_adjust_lock);
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zthr_wakeup(arc_adjust_zthr);
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}
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}
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typedef enum free_memory_reason_t {
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@ -4065,7 +4089,7 @@ arc_reclaim_needed(void)
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}
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static void
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arc_kmem_reap_now(void)
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arc_kmem_reap_soon(void)
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{
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size_t i;
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kmem_cache_t *prev_cache = NULL;
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@ -4091,16 +4115,6 @@ arc_kmem_reap_now(void)
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#endif
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#endif
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/*
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* If a kmem reap is already active, don't schedule more. We must
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* check for this because kmem_cache_reap_soon() won't actually
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* block on the cache being reaped (this is to prevent callers from
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* becoming implicitly blocked by a system-wide kmem reap -- which,
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* on a system with many, many full magazines, can take minutes).
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*/
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if (kmem_cache_reap_active())
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return;
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for (i = 0; i < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; i++) {
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if (zio_buf_cache[i] != prev_cache) {
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prev_cache = zio_buf_cache[i];
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@ -4126,139 +4140,162 @@ arc_kmem_reap_now(void)
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}
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}
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/* ARGSUSED */
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static boolean_t
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arc_adjust_cb_check(void *arg, zthr_t *zthr)
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{
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/*
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* This is necessary in order for the mdb ::arc dcmd to
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* show up to date information. Since the ::arc command
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* does not call the kstat's update function, without
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* this call, the command may show stale stats for the
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* anon, mru, mru_ghost, mfu, and mfu_ghost lists. Even
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* with this change, the data might be up to 1 second
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* out of date(the arc_adjust_zthr has a maximum sleep
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* time of 1 second); but that should suffice. The
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* arc_state_t structures can be queried directly if more
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* accurate information is needed.
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*/
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if (arc_ksp != NULL)
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arc_ksp->ks_update(arc_ksp, KSTAT_READ);
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/*
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* We have to rely on arc_get_data_impl() to tell us when to adjust,
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* rather than checking if we are overflowing here, so that we are
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* sure to not leave arc_get_data_impl() waiting on
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* arc_adjust_waiters_cv. If we have become "not overflowing" since
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* arc_get_data_impl() checked, we need to wake it up. We could
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* broadcast the CV here, but arc_get_data_impl() may have not yet
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* gone to sleep. We would need to use a mutex to ensure that this
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* function doesn't broadcast until arc_get_data_impl() has gone to
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* sleep (e.g. the arc_adjust_lock). However, the lock ordering of
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* such a lock would necessarily be incorrect with respect to the
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* zthr_lock, which is held before this function is called, and is
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* held by arc_get_data_impl() when it calls zthr_wakeup().
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*/
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return (arc_adjust_needed);
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}
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/*
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* Threads can block in arc_get_data_impl() waiting for this thread to evict
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* enough data and signal them to proceed. When this happens, the threads in
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* arc_get_data_impl() are sleeping while holding the hash lock for their
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* particular arc header. Thus, we must be careful to never sleep on a
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* hash lock in this thread. This is to prevent the following deadlock:
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*
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* - Thread A sleeps on CV in arc_get_data_impl() holding hash lock "L",
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* waiting for the reclaim thread to signal it.
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*
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* - arc_reclaim_thread() tries to acquire hash lock "L" using mutex_enter,
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* fails, and goes to sleep forever.
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*
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* This possible deadlock is avoided by always acquiring a hash lock
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* using mutex_tryenter() from arc_reclaim_thread().
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* Keep arc_size under arc_c by running arc_adjust which evicts data
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* from the ARC.
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*/
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/* ARGSUSED */
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static void
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arc_reclaim_thread(void *unused)
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static int
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arc_adjust_cb(void *arg, zthr_t *zthr)
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{
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hrtime_t growtime = 0;
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hrtime_t kmem_reap_time = 0;
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callb_cpr_t cpr;
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uint64_t evicted = 0;
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CALLB_CPR_INIT(&cpr, &arc_reclaim_lock, callb_generic_cpr, FTAG);
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mutex_enter(&arc_reclaim_lock);
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while (!arc_reclaim_thread_exit) {
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uint64_t evicted = 0;
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/* Evict from cache */
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evicted = arc_adjust();
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/*
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* If evicted is zero, we couldn't evict anything
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* via arc_adjust(). This could be due to hash lock
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* collisions, but more likely due to the majority of
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* arc buffers being unevictable. Therefore, even if
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* arc_size is above arc_c, another pass is unlikely to
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* be helpful and could potentially cause us to enter an
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* infinite loop. Additionally, zthr_iscancelled() is
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* checked here so that if the arc is shutting down, the
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* broadcast will wake any remaining arc adjust waiters.
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*/
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mutex_enter(&arc_adjust_lock);
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arc_adjust_needed = !zthr_iscancelled(arc_adjust_zthr) &&
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evicted > 0 && aggsum_compare(&arc_size, arc_c) > 0;
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if (!arc_adjust_needed) {
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/*
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* This is necessary in order for the mdb ::arc dcmd to
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* show up to date information. Since the ::arc command
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* does not call the kstat's update function, without
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* this call, the command may show stale stats for the
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* anon, mru, mru_ghost, mfu, and mfu_ghost lists. Even
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* with this change, the data might be up to 1 second
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* out of date; but that should suffice. The arc_state_t
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* structures can be queried directly if more accurate
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* information is needed.
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* We're either no longer overflowing, or we
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* can't evict anything more, so we should wake
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* up any waiters.
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*/
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if (arc_ksp != NULL)
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arc_ksp->ks_update(arc_ksp, KSTAT_READ);
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cv_broadcast(&arc_adjust_waiters_cv);
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}
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mutex_exit(&arc_adjust_lock);
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mutex_exit(&arc_reclaim_lock);
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return (0);
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}
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/* ARGSUSED */
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static boolean_t
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arc_reap_cb_check(void *arg, zthr_t *zthr)
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{
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int64_t free_memory = arc_available_memory();
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/*
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* If a kmem reap is already active, don't schedule more. We must
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* check for this because kmem_cache_reap_soon() won't actually
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* block on the cache being reaped (this is to prevent callers from
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* becoming implicitly blocked by a system-wide kmem reap -- which,
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* on a system with many, many full magazines, can take minutes).
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*/
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if (!kmem_cache_reap_active() &&
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free_memory < 0) {
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arc_no_grow = B_TRUE;
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arc_warm = B_TRUE;
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/*
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* We call arc_adjust() before (possibly) calling
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* arc_kmem_reap_now(), so that we can wake up
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* arc_get_data_impl() sooner.
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* Wait at least zfs_grow_retry (default 60) seconds
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* before considering growing.
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*/
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evicted = arc_adjust();
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int64_t free_memory = arc_available_memory();
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if (free_memory < 0) {
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hrtime_t curtime = gethrtime();
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arc_no_grow = B_TRUE;
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arc_warm = B_TRUE;
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/*
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* Wait at least zfs_grow_retry (default 60) seconds
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* before considering growing.
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*/
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growtime = curtime + SEC2NSEC(arc_grow_retry);
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/*
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* Wait at least arc_kmem_cache_reap_retry_ms
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* between arc_kmem_reap_now() calls. Without
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* this check it is possible to end up in a
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* situation where we spend lots of time
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* reaping caches, while we're near arc_c_min.
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*/
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if (curtime >= kmem_reap_time) {
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arc_kmem_reap_now();
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kmem_reap_time = gethrtime() +
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MSEC2NSEC(arc_kmem_cache_reap_retry_ms);
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}
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/*
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* If we are still low on memory, shrink the ARC
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* so that we have arc_shrink_min free space.
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*/
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free_memory = arc_available_memory();
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int64_t to_free =
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(arc_c >> arc_shrink_shift) - free_memory;
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if (to_free > 0) {
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#ifdef _KERNEL
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to_free = MAX(to_free, ptob(needfree));
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#endif
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arc_shrink(to_free);
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}
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} else if (free_memory < arc_c >> arc_no_grow_shift) {
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arc_no_grow = B_TRUE;
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} else if (gethrtime() >= growtime) {
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arc_no_grow = B_FALSE;
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}
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mutex_enter(&arc_reclaim_lock);
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/*
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* If evicted is zero, we couldn't evict anything via
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* arc_adjust(). This could be due to hash lock
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* collisions, but more likely due to the majority of
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* arc buffers being unevictable. Therefore, even if
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* arc_size is above arc_c, another pass is unlikely to
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* be helpful and could potentially cause us to enter an
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* infinite loop.
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*/
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if (aggsum_compare(&arc_size, arc_c) <= 0|| evicted == 0) {
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/*
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* We're either no longer overflowing, or we
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* can't evict anything more, so we should wake
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* up any threads before we go to sleep.
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*/
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cv_broadcast(&arc_reclaim_waiters_cv);
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/*
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* Block until signaled, or after one second (we
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* might need to perform arc_kmem_reap_now()
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* even if we aren't being signalled)
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*/
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CALLB_CPR_SAFE_BEGIN(&cpr);
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(void) cv_timedwait_hires(&arc_reclaim_thread_cv,
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&arc_reclaim_lock, SEC2NSEC(1), MSEC2NSEC(1), 0);
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CALLB_CPR_SAFE_END(&cpr, &arc_reclaim_lock);
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}
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arc_growtime = gethrtime() + SEC2NSEC(arc_grow_retry);
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return (B_TRUE);
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} else if (free_memory < arc_c >> arc_no_grow_shift) {
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arc_no_grow = B_TRUE;
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} else if (gethrtime() >= arc_growtime) {
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arc_no_grow = B_FALSE;
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}
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arc_reclaim_thread_exit = B_FALSE;
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cv_broadcast(&arc_reclaim_thread_cv);
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CALLB_CPR_EXIT(&cpr); /* drops arc_reclaim_lock */
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thread_exit();
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return (B_FALSE);
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}
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/*
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* Keep enough free memory in the system by reaping the ARC's kmem
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* caches. To cause more slabs to be reapable, we may reduce the
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* target size of the cache (arc_c), causing the arc_adjust_cb()
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* to free more buffers.
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*/
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/* ARGSUSED */
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static int
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arc_reap_cb(void *arg, zthr_t *zthr)
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{
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int64_t free_memory;
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/*
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* Kick off asynchronous kmem_reap()'s of all our caches.
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*/
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arc_kmem_reap_soon();
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/*
|
||||
* 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);
|
||||
|
||||
/*
|
||||
* 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
|
||||
to_free = MAX(to_free, ptob(needfree));
|
||||
#endif
|
||||
arc_reduce_target_size(to_free);
|
||||
}
|
||||
|
||||
return (0);
|
||||
}
|
||||
|
||||
/*
|
||||
@ -4302,11 +4339,15 @@ 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;
|
||||
}
|
||||
|
||||
|
||||
if (arc_no_grow)
|
||||
return;
|
||||
|
||||
@ -4410,7 +4451,7 @@ arc_get_data_impl(arc_buf_hdr_t *hdr, uint64_t size, void *tag)
|
||||
* 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
|
||||
@ -4424,11 +4465,12 @@ arc_get_data_impl(arc_buf_hdr_t *hdr, uint64_t size, void *tag)
|
||||
* 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);
|
||||
@ -6081,10 +6123,8 @@ arc_init(void)
|
||||
#else
|
||||
uint64_t allmem = (physmem * PAGESIZE) / 2;
|
||||
#endif
|
||||
|
||||
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_adjust_lock, NULL, MUTEX_DEFAULT, NULL);
|
||||
cv_init(&arc_adjust_waiters_cv, NULL, CV_DEFAULT, NULL);
|
||||
|
||||
/* Convert seconds to clock ticks */
|
||||
arc_min_prefetch_lifespan = 1 * hz;
|
||||
@ -6169,9 +6209,14 @@ arc_init(void)
|
||||
arc_c = arc_c_min;
|
||||
|
||||
arc_state_init();
|
||||
buf_init();
|
||||
|
||||
arc_reclaim_thread_exit = B_FALSE;
|
||||
/*
|
||||
* 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();
|
||||
|
||||
arc_ksp = kstat_create("zfs", 0, "arcstats", "misc", KSTAT_TYPE_NAMED,
|
||||
sizeof (arc_stats) / sizeof (kstat_named_t), KSTAT_FLAG_VIRTUAL);
|
||||
@ -6182,10 +6227,12 @@ 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(arc_adjust_cb_check,
|
||||
arc_adjust_cb, NULL);
|
||||
arc_reap_zthr = zthr_create_timer(arc_reap_cb_check,
|
||||
arc_reap_cb, NULL, SEC2NSEC(1));
|
||||
|
||||
arc_dead = B_FALSE;
|
||||
arc_initialized = B_TRUE;
|
||||
arc_warm = B_FALSE;
|
||||
|
||||
/*
|
||||
@ -6207,31 +6254,24 @@ arc_init(void)
|
||||
void
|
||||
arc_fini(void)
|
||||
{
|
||||
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);
|
||||
|
||||
arc_dead = B_TRUE;
|
||||
arc_initialized = B_FALSE;
|
||||
|
||||
if (arc_ksp != NULL) {
|
||||
kstat_delete(arc_ksp);
|
||||
arc_ksp = NULL;
|
||||
}
|
||||
|
||||
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);
|
||||
|
||||
(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();
|
||||
|
@ -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);
|
||||
|
||||
|
@ -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);
|
||||
@ -199,6 +212,18 @@ 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);
|
||||
@ -208,6 +233,7 @@ zthr_create(zthr_checkfunc_t *checkfunc, zthr_func_t *func, void *arg)
|
||||
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);
|
||||
|
Loading…
Reference in New Issue
Block a user