diff options
author | David Teigland <teigland@redhat.com> | 2011-04-05 13:16:24 -0500 |
---|---|---|
committer | David Teigland <teigland@redhat.com> | 2011-07-15 12:30:43 -0500 |
commit | 23e8e1aaacb10d9f05e44a93e10ea4ee5b3838a5 (patch) | |
tree | 7c94bc4eeb9dfd85a26869003c56dc45fc6fd697 /fs/dlm/ast.c | |
parent | 883ba74f43092823d0ed4c6b21f0171e9b334607 (diff) |
dlm: use workqueue for callbacks
Instead of creating our own kthread (dlm_astd) to deliver
callbacks for all lockspaces, use a per-lockspace workqueue
to deliver the callbacks. This eliminates complications and
slowdowns from many lockspaces sharing the same thread.
Signed-off-by: David Teigland <teigland@redhat.com>
Diffstat (limited to 'fs/dlm/ast.c')
-rw-r--r-- | fs/dlm/ast.c | 262 |
1 files changed, 114 insertions, 148 deletions
diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c index abc49f29245..4f29add0e7d 100644 --- a/fs/dlm/ast.c +++ b/fs/dlm/ast.c @@ -14,17 +14,9 @@ #include "dlm_internal.h" #include "lock.h" #include "user.h" -#include "ast.h" - -#define WAKE_ASTS 0 - -static uint64_t ast_seq_count; -static struct list_head ast_queue; -static spinlock_t ast_queue_lock; -static struct task_struct * astd_task; -static unsigned long astd_wakeflags; -static struct mutex astd_running; +static uint64_t dlm_cb_seq; +static spinlock_t dlm_cb_seq_spin; static void dlm_dump_lkb_callbacks(struct dlm_lkb *lkb) { @@ -57,21 +49,13 @@ static void dlm_dump_lkb_callbacks(struct dlm_lkb *lkb) } } -void dlm_del_ast(struct dlm_lkb *lkb) -{ - spin_lock(&ast_queue_lock); - if (!list_empty(&lkb->lkb_astqueue)) - list_del_init(&lkb->lkb_astqueue); - spin_unlock(&ast_queue_lock); -} - int dlm_add_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode, int status, uint32_t sbflags, uint64_t seq) { struct dlm_ls *ls = lkb->lkb_resource->res_ls; uint64_t prev_seq; int prev_mode; - int i; + int i, rv; for (i = 0; i < DLM_CALLBACKS_SIZE; i++) { if (lkb->lkb_callbacks[i].seq) @@ -100,7 +84,8 @@ int dlm_add_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode, mode, (unsigned long long)prev_seq, prev_mode); - return 0; + rv = 0; + goto out; } } @@ -109,6 +94,7 @@ int dlm_add_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode, lkb->lkb_callbacks[i].mode = mode; lkb->lkb_callbacks[i].sb_status = status; lkb->lkb_callbacks[i].sb_flags = (sbflags & 0x000000FF); + rv = 0; break; } @@ -117,21 +103,24 @@ int dlm_add_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode, lkb->lkb_id, (unsigned long long)seq, flags, mode, status, sbflags); dlm_dump_lkb_callbacks(lkb); - return -1; + rv = -1; + goto out; } - - return 0; + out: + return rv; } int dlm_rem_lkb_callback(struct dlm_ls *ls, struct dlm_lkb *lkb, struct dlm_callback *cb, int *resid) { - int i; + int i, rv; *resid = 0; - if (!lkb->lkb_callbacks[0].seq) - return -ENOENT; + if (!lkb->lkb_callbacks[0].seq) { + rv = -ENOENT; + goto out; + } /* oldest undelivered cb is callbacks[0] */ @@ -163,7 +152,8 @@ int dlm_rem_lkb_callback(struct dlm_ls *ls, struct dlm_lkb *lkb, cb->mode, (unsigned long long)lkb->lkb_last_cast.seq, lkb->lkb_last_cast.mode); - return 0; + rv = 0; + goto out; } } @@ -176,171 +166,147 @@ int dlm_rem_lkb_callback(struct dlm_ls *ls, struct dlm_lkb *lkb, memcpy(&lkb->lkb_last_bast, cb, sizeof(struct dlm_callback)); lkb->lkb_last_bast_time = ktime_get(); } - - return 0; + rv = 0; + out: + return rv; } -void dlm_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode, int status, - uint32_t sbflags) +void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status, + uint32_t sbflags) { - uint64_t seq; + struct dlm_ls *ls = lkb->lkb_resource->res_ls; + uint64_t new_seq, prev_seq; int rv; - spin_lock(&ast_queue_lock); - - seq = ++ast_seq_count; + spin_lock(&dlm_cb_seq_spin); + new_seq = ++dlm_cb_seq; + spin_unlock(&dlm_cb_seq_spin); if (lkb->lkb_flags & DLM_IFL_USER) { - spin_unlock(&ast_queue_lock); - dlm_user_add_ast(lkb, flags, mode, status, sbflags, seq); + dlm_user_add_ast(lkb, flags, mode, status, sbflags, new_seq); return; } - rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, seq); - if (rv < 0) { - spin_unlock(&ast_queue_lock); - return; - } + mutex_lock(&lkb->lkb_cb_mutex); + prev_seq = lkb->lkb_callbacks[0].seq; - if (list_empty(&lkb->lkb_astqueue)) { + rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, new_seq); + if (rv < 0) + goto out; + + if (!prev_seq) { kref_get(&lkb->lkb_ref); - list_add_tail(&lkb->lkb_astqueue, &ast_queue); - } - spin_unlock(&ast_queue_lock); - set_bit(WAKE_ASTS, &astd_wakeflags); - wake_up_process(astd_task); + if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) { + mutex_lock(&ls->ls_cb_mutex); + list_add(&lkb->lkb_cb_list, &ls->ls_cb_delay); + mutex_unlock(&ls->ls_cb_mutex); + } else { + queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work); + } + } + out: + mutex_unlock(&lkb->lkb_cb_mutex); } -static void process_asts(void) +void dlm_callback_work(struct work_struct *work) { - struct dlm_ls *ls = NULL; - struct dlm_rsb *r = NULL; - struct dlm_lkb *lkb; + struct dlm_lkb *lkb = container_of(work, struct dlm_lkb, lkb_cb_work); + struct dlm_ls *ls = lkb->lkb_resource->res_ls; void (*castfn) (void *astparam); void (*bastfn) (void *astparam, int mode); struct dlm_callback callbacks[DLM_CALLBACKS_SIZE]; int i, rv, resid; -repeat: - spin_lock(&ast_queue_lock); - list_for_each_entry(lkb, &ast_queue, lkb_astqueue) { - r = lkb->lkb_resource; - ls = r->res_ls; + memset(&callbacks, 0, sizeof(callbacks)); - if (dlm_locking_stopped(ls)) - continue; - - /* we remove from astqueue list and remove everything in - lkb_callbacks before releasing the spinlock so empty - lkb_astqueue is always consistent with empty lkb_callbacks */ - - list_del_init(&lkb->lkb_astqueue); - - castfn = lkb->lkb_astfn; - bastfn = lkb->lkb_bastfn; + mutex_lock(&lkb->lkb_cb_mutex); + if (!lkb->lkb_callbacks[0].seq) { + /* no callback work exists, shouldn't happen */ + log_error(ls, "dlm_callback_work %x no work", lkb->lkb_id); + dlm_print_lkb(lkb); + dlm_dump_lkb_callbacks(lkb); + } - memset(&callbacks, 0, sizeof(callbacks)); + for (i = 0; i < DLM_CALLBACKS_SIZE; i++) { + rv = dlm_rem_lkb_callback(ls, lkb, &callbacks[i], &resid); + if (rv < 0) + break; + } - for (i = 0; i < DLM_CALLBACKS_SIZE; i++) { - rv = dlm_rem_lkb_callback(ls, lkb, &callbacks[i], &resid); - if (rv < 0) - break; - } - spin_unlock(&ast_queue_lock); + if (resid) { + /* cbs remain, loop should have removed all, shouldn't happen */ + log_error(ls, "dlm_callback_work %x resid %d", lkb->lkb_id, + resid); + dlm_print_lkb(lkb); + dlm_dump_lkb_callbacks(lkb); + } + mutex_unlock(&lkb->lkb_cb_mutex); - if (resid) { - /* shouldn't happen, for loop should have removed all */ - log_error(ls, "callback resid %d lkb %x", - resid, lkb->lkb_id); - } + castfn = lkb->lkb_astfn; + bastfn = lkb->lkb_bastfn; - for (i = 0; i < DLM_CALLBACKS_SIZE; i++) { - if (!callbacks[i].seq) - break; - if (callbacks[i].flags & DLM_CB_SKIP) { - continue; - } else if (callbacks[i].flags & DLM_CB_BAST) { - bastfn(lkb->lkb_astparam, callbacks[i].mode); - } else if (callbacks[i].flags & DLM_CB_CAST) { - lkb->lkb_lksb->sb_status = callbacks[i].sb_status; - lkb->lkb_lksb->sb_flags = callbacks[i].sb_flags; - castfn(lkb->lkb_astparam); - } + for (i = 0; i < DLM_CALLBACKS_SIZE; i++) { + if (!callbacks[i].seq) + break; + if (callbacks[i].flags & DLM_CB_SKIP) { + continue; + } else if (callbacks[i].flags & DLM_CB_BAST) { + bastfn(lkb->lkb_astparam, callbacks[i].mode); + } else if (callbacks[i].flags & DLM_CB_CAST) { + lkb->lkb_lksb->sb_status = callbacks[i].sb_status; + lkb->lkb_lksb->sb_flags = callbacks[i].sb_flags; + castfn(lkb->lkb_astparam); } - - /* removes ref for ast_queue, may cause lkb to be freed */ - dlm_put_lkb(lkb); - - cond_resched(); - goto repeat; } - spin_unlock(&ast_queue_lock); -} - -static inline int no_asts(void) -{ - int ret; - spin_lock(&ast_queue_lock); - ret = list_empty(&ast_queue); - spin_unlock(&ast_queue_lock); - return ret; + /* undo kref_get from dlm_add_callback, may cause lkb to be freed */ + dlm_put_lkb(lkb); } -static int dlm_astd(void *data) +int dlm_callback_start(struct dlm_ls *ls) { - while (!kthread_should_stop()) { - set_current_state(TASK_INTERRUPTIBLE); - if (!test_bit(WAKE_ASTS, &astd_wakeflags)) - schedule(); - set_current_state(TASK_RUNNING); - - mutex_lock(&astd_running); - if (test_and_clear_bit(WAKE_ASTS, &astd_wakeflags)) - process_asts(); - mutex_unlock(&astd_running); + ls->ls_callback_wq = alloc_workqueue("dlm_callback", + WQ_UNBOUND | WQ_MEM_RECLAIM, 1); + if (!ls->ls_callback_wq) { + log_print("can't start dlm_callback workqueue"); + return -ENOMEM; } return 0; } -void dlm_astd_wake(void) +void dlm_callback_stop(struct dlm_ls *ls) { - if (!no_asts()) { - set_bit(WAKE_ASTS, &astd_wakeflags); - wake_up_process(astd_task); - } + if (ls->ls_callback_wq) + destroy_workqueue(ls->ls_callback_wq); } -int dlm_astd_start(void) +void dlm_callback_suspend(struct dlm_ls *ls) { - struct task_struct *p; - int error = 0; - - INIT_LIST_HEAD(&ast_queue); - spin_lock_init(&ast_queue_lock); - mutex_init(&astd_running); - - p = kthread_run(dlm_astd, NULL, "dlm_astd"); - if (IS_ERR(p)) - error = PTR_ERR(p); - else - astd_task = p; - return error; -} + set_bit(LSFL_CB_DELAY, &ls->ls_flags); -void dlm_astd_stop(void) -{ - kthread_stop(astd_task); + if (ls->ls_callback_wq) + flush_workqueue(ls->ls_callback_wq); } -void dlm_astd_suspend(void) +void dlm_callback_resume(struct dlm_ls *ls) { - mutex_lock(&astd_running); -} + struct dlm_lkb *lkb, *safe; + int count = 0; -void dlm_astd_resume(void) -{ - mutex_unlock(&astd_running); + clear_bit(LSFL_CB_DELAY, &ls->ls_flags); + + if (!ls->ls_callback_wq) + return; + + mutex_lock(&ls->ls_cb_mutex); + list_for_each_entry_safe(lkb, safe, &ls->ls_cb_delay, lkb_cb_list) { + list_del_init(&lkb->lkb_cb_list); + queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work); + count++; + } + mutex_unlock(&ls->ls_cb_mutex); + + log_debug(ls, "dlm_callback_resume %d", count); } |