fio: Simplify forking of processes
[fio.git] / backend.c
index c18cf209204fa6b7670586bab63bca5b91556b8a..ce23c6960f0304ea6a1eaef56efdbd3545dc76f5 100644 (file)
--- a/backend.c
+++ b/backend.c
 #include "lib/getrusage.h"
 #include "idletime.h"
 #include "err.h"
-#include "lib/tp.h"
 #include "workqueue.h"
 #include "lib/mountcheck.h"
-
-static pthread_t helper_thread;
-static pthread_mutex_t helper_lock;
-pthread_cond_t helper_cond;
-int helper_do_stat = 0;
+#include "rate-submit.h"
+#include "helper_thread.h"
 
 static struct fio_mutex *startup_mutex;
 static struct flist_head *cgroup_list;
@@ -79,7 +75,6 @@ unsigned int stat_number = 0;
 int shm_id = 0;
 int temp_stall_ts;
 unsigned long done_secs = 0;
-volatile int helper_exit = 0;
 
 #define PAGE_ALIGN(buf)        \
        (char *) (((uintptr_t) (buf) + page_mask) & ~page_mask)
@@ -309,6 +304,8 @@ requeue:
                put_io_u(td, io_u);
                return true;
        } else if (ret == FIO_Q_QUEUED) {
+               if (td_io_commit(td))
+                       return true;
                if (io_u_queued_complete(td, 1) < 0)
                        return true;
        } else if (ret == FIO_Q_COMPLETED) {
@@ -444,6 +441,12 @@ static int wait_for_completions(struct thread_data *td, struct timeval *time)
        int min_evts = 0;
        int ret;
 
+       if (td->flags & TD_F_REGROW_LOGS) {
+               ret = io_u_quiesce(td);
+               regrow_logs(td);
+               return ret;
+       }
+
        /*
         * if the queue is full, we MUST reap at least 1 event
         */
@@ -520,6 +523,17 @@ sync_done:
                        if (*ret < 0)
                                break;
                }
+
+               if (td->flags & TD_F_REGROW_LOGS)
+                       regrow_logs(td);
+
+               /*
+                * when doing I/O (not when verifying),
+                * check for any errors that are to be ignored
+                */
+               if (!from_verify)
+                       break;
+
                return 0;
        case FIO_Q_QUEUED:
                /*
@@ -808,12 +822,15 @@ static long long usec_for_io(struct thread_data *td, enum fio_ddir ddir)
  *
  * Returns number of bytes written and trimmed.
  */
-static uint64_t do_io(struct thread_data *td)
+static void do_io(struct thread_data *td, uint64_t *bytes_done)
 {
        unsigned int i;
        int ret = 0;
        uint64_t total_bytes, bytes_issued = 0;
 
+       for (i = 0; i < DDIR_RWDIR_CNT; i++)
+               bytes_done[i] = td->bytes_done[i];
+
        if (in_ramp_time(td))
                td_set_runstate(td, TD_RAMP);
        else
@@ -868,7 +885,14 @@ static uint64_t do_io(struct thread_data *td)
                if (flow_threshold_exceeded(td))
                        continue;
 
-               if (!td->o.time_based && bytes_issued >= total_bytes)
+               /*
+                * Break if we exceeded the bytes. The exception is time
+                * based runs, but we still need to break out of the loop
+                * for those to run verification, if enabled.
+                */
+               if (bytes_issued >= total_bytes &&
+                   (!td->o.time_based ||
+                    (td->o.time_based && td->o.verify != VERIFY_NONE)))
                        break;
 
                io_u = get_io_u(td);
@@ -934,13 +958,10 @@ static uint64_t do_io(struct thread_data *td)
                        if (td->error)
                                break;
 
-                       ret = workqueue_enqueue(&td->io_wq, &io_u->work);
-                       if (ret)
-                               ret = FIO_Q_QUEUED;
-                       else
-                               ret = FIO_Q_BUSY;
+                       workqueue_enqueue(&td->io_wq, &io_u->work);
+                       ret = FIO_Q_QUEUED;
 
-                       if (ret == FIO_Q_QUEUED && ddir_rw(ddir)) {
+                       if (ddir_rw(ddir)) {
                                td->io_issues[ddir]++;
                                td->io_issue_bytes[ddir] += blen;
                                td->rate_io_issue_bytes[ddir] += blen;
@@ -977,7 +998,7 @@ reap:
 
                if (!in_ramp_time(td) && should_check_rate(td)) {
                        if (check_min_rate(td, &comp_time)) {
-                               if (exitall_on_terminate)
+                               if (exitall_on_terminate || td->o.exitall_error)
                                        fio_terminate_threads(td->groupid);
                                td_verror(td, EIO, "check_min_rate");
                                break;
@@ -1049,7 +1070,43 @@ reap:
        if (!ddir_rw_sum(td->this_io_bytes))
                td->done = 1;
 
-       return td->bytes_done[DDIR_WRITE] + td->bytes_done[DDIR_TRIM];
+       for (i = 0; i < DDIR_RWDIR_CNT; i++)
+               bytes_done[i] = td->bytes_done[i] - bytes_done[i];
+}
+
+static void free_file_completion_logging(struct thread_data *td)
+{
+       struct fio_file *f;
+       unsigned int i;
+
+       for_each_file(td, f, i) {
+               if (!f->last_write_comp)
+                       break;
+               sfree(f->last_write_comp);
+       }
+}
+
+static int init_file_completion_logging(struct thread_data *td,
+                                       unsigned int depth)
+{
+       struct fio_file *f;
+       unsigned int i;
+
+       if (td->o.verify == VERIFY_NONE || !td->o.verify_state_save)
+               return 0;
+
+       for_each_file(td, f, i) {
+               f->last_write_comp = scalloc(depth, sizeof(uint64_t));
+               if (!f->last_write_comp)
+                       goto cleanup;
+       }
+
+       return 0;
+
+cleanup:
+       free_file_completion_logging(td);
+       log_err("fio: failed to alloc write comp data\n");
+       return 1;
 }
 
 static void cleanup_io_u(struct thread_data *td)
@@ -1070,8 +1127,7 @@ static void cleanup_io_u(struct thread_data *td)
        io_u_qexit(&td->io_u_freelist);
        io_u_qexit(&td->io_u_all);
 
-       if (td->last_write_comp)
-               sfree(td->last_write_comp);
+       free_file_completion_logging(td);
 }
 
 static int init_io_u(struct thread_data *td)
@@ -1188,13 +1244,8 @@ static int init_io_u(struct thread_data *td)
                p += max_bs;
        }
 
-       if (td->o.verify != VERIFY_NONE) {
-               td->last_write_comp = scalloc(max_units, sizeof(uint64_t));
-               if (!td->last_write_comp) {
-                       log_err("fio: failed to alloc write comp data\n");
-                       return 1;
-               }
-       }
+       if (init_file_completion_logging(td, max_units))
+               return 1;
 
        return 0;
 }
@@ -1292,7 +1343,7 @@ static bool keep_running(struct thread_data *td)
                if (diff < td_max_bs(td))
                        return false;
 
-               if (fio_files_done(td))
+               if (fio_files_done(td) && !td->o.io_limit)
                        return false;
 
                return true;
@@ -1361,229 +1412,9 @@ static uint64_t do_dry_run(struct thread_data *td)
        return td->bytes_done[DDIR_WRITE] + td->bytes_done[DDIR_TRIM];
 }
 
-static void io_workqueue_fn(struct submit_worker *sw,
-                           struct workqueue_work *work)
-{
-       struct io_u *io_u = container_of(work, struct io_u, work);
-       const enum fio_ddir ddir = io_u->ddir;
-       struct thread_data *td = sw->private;
-       int ret;
-
-       dprint(FD_RATE, "io_u %p queued by %u\n", io_u, gettid());
-
-       io_u_set(io_u, IO_U_F_NO_FILE_PUT);
-
-       td->cur_depth++;
-
-       do {
-               ret = td_io_queue(td, io_u);
-               if (ret != FIO_Q_BUSY)
-                       break;
-               ret = io_u_queued_complete(td, 1);
-               if (ret > 0)
-                       td->cur_depth -= ret;
-               io_u_clear(io_u, IO_U_F_FLIGHT);
-       } while (1);
-
-       dprint(FD_RATE, "io_u %p ret %d by %u\n", io_u, ret, gettid());
-
-       io_queue_event(td, io_u, &ret, ddir, NULL, 0, NULL);
-
-       if (ret == FIO_Q_COMPLETED)
-               td->cur_depth--;
-       else if (ret == FIO_Q_QUEUED) {
-               unsigned int min_evts;
-
-               if (td->o.iodepth == 1)
-                       min_evts = 1;
-               else
-                       min_evts = 0;
-
-               ret = io_u_queued_complete(td, min_evts);
-               if (ret > 0)
-                       td->cur_depth -= ret;
-       } else if (ret == FIO_Q_BUSY) {
-               ret = io_u_queued_complete(td, td->cur_depth);
-               if (ret > 0)
-                       td->cur_depth -= ret;
-       }
-}
-
-static bool io_workqueue_pre_sleep_flush_fn(struct submit_worker *sw)
-{
-       struct thread_data *td = sw->private;
-
-       if (td->io_u_queued || td->cur_depth || td->io_u_in_flight)
-               return true;
-
-       return false;
-}
-
-static void io_workqueue_pre_sleep_fn(struct submit_worker *sw)
-{
-       struct thread_data *td = sw->private;
-       int ret;
-
-       ret = io_u_quiesce(td);
-       if (ret > 0)
-               td->cur_depth -= ret;
-}
-
-static int io_workqueue_alloc_fn(struct submit_worker *sw)
-{
+struct fork_data {
        struct thread_data *td;
-
-       td = calloc(1, sizeof(*td));
-       sw->private = td;
-       return 0;
-}
-
-static void io_workqueue_free_fn(struct submit_worker *sw)
-{
-       free(sw->private);
-       sw->private = NULL;
-}
-
-static int io_workqueue_init_worker_fn(struct submit_worker *sw)
-{
-       struct thread_data *parent = sw->wq->td;
-       struct thread_data *td = sw->private;
-       int fio_unused ret;
-
-       memcpy(&td->o, &parent->o, sizeof(td->o));
-       memcpy(&td->ts, &parent->ts, sizeof(td->ts));
-       td->o.uid = td->o.gid = -1U;
-       dup_files(td, parent);
-       td->eo = parent->eo;
-       fio_options_mem_dupe(td);
-
-       if (ioengine_load(td))
-               goto err;
-
-       if (td->o.odirect)
-               td->io_ops->flags |= FIO_RAWIO;
-
-       td->pid = gettid();
-
-       INIT_FLIST_HEAD(&td->io_log_list);
-       INIT_FLIST_HEAD(&td->io_hist_list);
-       INIT_FLIST_HEAD(&td->verify_list);
-       INIT_FLIST_HEAD(&td->trim_list);
-       INIT_FLIST_HEAD(&td->next_rand_list);
-       td->io_hist_tree = RB_ROOT;
-
-       td->o.iodepth = 1;
-       if (td_io_init(td))
-               goto err_io_init;
-
-       fio_gettime(&td->epoch, NULL);
-       fio_getrusage(&td->ru_start);
-       clear_io_state(td, 1);
-
-       td_set_runstate(td, TD_RUNNING);
-       td->flags |= TD_F_CHILD;
-       td->parent = parent;
-       return 0;
-
-err_io_init:
-       close_ioengine(td);
-err:
-       return 1;
-
-}
-
-static void io_workqueue_exit_worker_fn(struct submit_worker *sw,
-                                       unsigned int *sum_cnt)
-{
-       struct thread_data *td = sw->private;
-
-       (*sum_cnt)++;
-       sum_thread_stats(&sw->wq->td->ts, &td->ts, *sum_cnt == 1);
-
-       fio_options_free(td);
-       close_and_free_files(td);
-       if (td->io_ops)
-               close_ioengine(td);
-       td_set_runstate(td, TD_EXITED);
-}
-
-#ifdef CONFIG_SFAA
-static void sum_val(uint64_t *dst, uint64_t *src)
-{
-       if (*src) {
-               __sync_fetch_and_add(dst, *src);
-               *src = 0;
-       }
-}
-#else
-static void sum_val(uint64_t *dst, uint64_t *src)
-{
-       if (*src) {
-               *dst += *src;
-               *src = 0;
-       }
-}
-#endif
-
-static void pthread_double_unlock(pthread_mutex_t *lock1,
-                                 pthread_mutex_t *lock2)
-{
-#ifndef CONFIG_SFAA
-       pthread_mutex_unlock(lock1);
-       pthread_mutex_unlock(lock2);
-#endif
-}
-
-static void pthread_double_lock(pthread_mutex_t *lock1, pthread_mutex_t *lock2)
-{
-#ifndef CONFIG_SFAA
-       if (lock1 < lock2) {
-               pthread_mutex_lock(lock1);
-               pthread_mutex_lock(lock2);
-       } else {
-               pthread_mutex_lock(lock2);
-               pthread_mutex_lock(lock1);
-       }
-#endif
-}
-
-static void sum_ddir(struct thread_data *dst, struct thread_data *src,
-                    enum fio_ddir ddir)
-{
-       pthread_double_lock(&dst->io_wq.stat_lock, &src->io_wq.stat_lock);
-
-       sum_val(&dst->io_bytes[ddir], &src->io_bytes[ddir]);
-       sum_val(&dst->io_blocks[ddir], &src->io_blocks[ddir]);
-       sum_val(&dst->this_io_blocks[ddir], &src->this_io_blocks[ddir]);
-       sum_val(&dst->this_io_bytes[ddir], &src->this_io_bytes[ddir]);
-       sum_val(&dst->bytes_done[ddir], &src->bytes_done[ddir]);
-
-       pthread_double_unlock(&dst->io_wq.stat_lock, &src->io_wq.stat_lock);
-}
-
-static void io_workqueue_update_acct_fn(struct submit_worker *sw)
-{
-       struct thread_data *src = sw->private;
-       struct thread_data *dst = sw->wq->td;
-
-       if (td_read(src))
-               sum_ddir(dst, src, DDIR_READ);
-       if (td_write(src))
-               sum_ddir(dst, src, DDIR_WRITE);
-       if (td_trim(src))
-               sum_ddir(dst, src, DDIR_TRIM);
-
-}
-
-struct workqueue_ops rated_wq_ops = {
-       .fn                     = io_workqueue_fn,
-       .pre_sleep_flush_fn     = io_workqueue_pre_sleep_flush_fn,
-       .pre_sleep_fn           = io_workqueue_pre_sleep_fn,
-       .update_acct_fn         = io_workqueue_update_acct_fn,
-       .alloc_worker_fn        = io_workqueue_alloc_fn,
-       .free_worker_fn         = io_workqueue_free_fn,
-       .init_worker_fn         = io_workqueue_init_worker_fn,
-       .exit_worker_fn         = io_workqueue_exit_worker_fn,
+       struct sk_out *sk_out;
 };
 
 /*
@@ -1592,13 +1423,18 @@ struct workqueue_ops rated_wq_ops = {
  */
 static void *thread_main(void *data)
 {
+       struct fork_data *fd = data;
        unsigned long long elapsed_us[DDIR_RWDIR_CNT] = { 0, };
-       struct thread_data *td = data;
+       struct thread_data *td = fd->td;
        struct thread_options *o = &td->o;
+       struct sk_out *sk_out = fd->sk_out;
        pthread_condattr_t attr;
        int clear_state;
        int ret;
 
+       sk_out_assign(sk_out);
+       free(fd);
+
        if (!o->use_thread) {
                setsid();
                td->pid = getpid();
@@ -1644,6 +1480,14 @@ static void *thread_main(void *data)
                goto err;
        }
 
+       /*
+        * Do this early, we don't want the compress threads to be limited
+        * to the same CPUs as the IO workers. So do this before we set
+        * any potential CPU affinity
+        */
+       if (iolog_compress_init(td, sk_out))
+               goto err;
+
        /*
         * If we have a gettimeofday() thread, make sure we exclude that
         * thread from this job
@@ -1778,13 +1622,9 @@ static void *thread_main(void *data)
                        goto err;
        }
 
-       if (td->flags & TD_F_COMPRESS_LOG)
-               tp_init(&td->tp_data);
-
        fio_verify_init(td);
 
-       if ((o->io_submit_mode == IO_MODE_OFFLOAD) &&
-           workqueue_init(td, &td->io_wq, &rated_wq_ops, td->o.iodepth))
+       if (rate_submit_init(td, sk_out))
                goto err;
 
        fio_gettime(&td->epoch, NULL);
@@ -1816,8 +1656,19 @@ static void *thread_main(void *data)
 
                if (td->o.verify_only && (td_write(td) || td_rw(td)))
                        verify_bytes = do_dry_run(td);
-               else
-                       verify_bytes = do_io(td);
+               else {
+                       uint64_t bytes_done[DDIR_RWDIR_CNT];
+
+                       do_io(td, bytes_done);
+
+                       if (!ddir_rw_sum(bytes_done)) {
+                               fio_mark_td_terminate(td);
+                               verify_bytes = 0;
+                       } else {
+                               verify_bytes = bytes_done[DDIR_WRITE] +
+                                               bytes_done[DDIR_TRIM];
+                       }
+               }
 
                clear_state = 1;
 
@@ -1868,6 +1719,8 @@ static void *thread_main(void *data)
                        break;
        }
 
+       td_set_runstate(td, TD_FINISHING);
+
        update_rusage_stat(td);
        td->ts.total_run_time = mtime_since_now(&td->epoch);
        td->ts.io_bytes[DDIR_READ] = td->io_bytes[DDIR_READ];
@@ -1880,18 +1733,15 @@ static void *thread_main(void *data)
 
        fio_unpin_memory(td);
 
-       fio_writeout_logs(td);
+       td_writeout_logs(td, true);
 
-       if (o->io_submit_mode == IO_MODE_OFFLOAD)
-               workqueue_exit(&td->io_wq);
-
-       if (td->flags & TD_F_COMPRESS_LOG)
-               tp_exit(&td->tp_data);
+       iolog_compress_exit(td);
+       rate_submit_exit(td);
 
        if (o->exec_postrun)
                exec_string(o, o->exec_postrun, (const char *)"postrun");
 
-       if (exitall_on_terminate)
+       if (exitall_on_terminate || (o->exitall_error && td->error))
                fio_terminate_threads(td->groupid);
 
 err:
@@ -1908,6 +1758,15 @@ err:
        cgroup_shutdown(td, &cgroup_mnt);
        verify_free_state(td);
 
+       if (td->zone_state_index) {
+               int i;
+
+               for (i = 0; i < DDIR_RWDIR_CNT; i++)
+                       free(td->zone_state_index[i]);
+               free(td->zone_state_index);
+               td->zone_state_index = NULL;
+       }
+
        if (fio_option_is_set(o, cpumask)) {
                ret = fio_cpuset_exit(&o->cpumask);
                if (ret)
@@ -1931,44 +1790,15 @@ err:
         */
        check_update_rusage(td);
 
+       sk_out_drop();
        return (void *) (uintptr_t) td->error;
 }
 
-
-/*
- * We cannot pass the td data into a forked process, so attach the td and
- * pass it to the thread worker.
- */
-static int fork_main(int shmid, int offset)
-{
-       struct thread_data *td;
-       void *data, *ret;
-
-#if !defined(__hpux) && !defined(CONFIG_NO_SHM)
-       data = shmat(shmid, NULL, 0);
-       if (data == (void *) -1) {
-               int __err = errno;
-
-               perror("shmat");
-               return __err;
-       }
-#else
-       /*
-        * HP-UX inherits shm mappings?
-        */
-       data = threads;
-#endif
-
-       td = data + offset * sizeof(struct thread_data);
-       ret = thread_main(td);
-       shmdt(data);
-       return (int) (uintptr_t) ret;
-}
-
 static void dump_td_info(struct thread_data *td)
 {
-       log_err("fio: job '%s' hasn't exited in %lu seconds, it appears to "
-               "be stuck. Doing forceful exit of this job.\n", td->o.name,
+       log_err("fio: job '%s' (state=%d) hasn't exited in %lu seconds, it "
+               "appears to be stuck. Doing forceful exit of this job.\n",
+                       td->o.name, td->runstate,
                        (unsigned long) time_since_now(&td->terminate_time));
 }
 
@@ -2054,6 +1884,7 @@ static void reap_threads(unsigned int *nr_running, unsigned int *t_rate,
                 * move on.
                 */
                if (td->terminate &&
+                   td->runstate < TD_FSYNCING &&
                    time_since_now(&td->terminate_time) >= FIO_REAP_TIMEOUT) {
                        dump_td_info(td);
                        td_set_runstate(td, TD_REAPED);
@@ -2142,12 +1973,11 @@ static int fio_verify_load_state(struct thread_data *td)
 
        if (is_backend) {
                void *data;
-               int ver;
 
                ret = fio_server_get_verify_state(td->o.name,
-                                       td->thread_number - 1, &data, &ver);
+                                       td->thread_number - 1, &data);
                if (!ret)
-                       verify_convert_assign_state(td, data, ver);
+                       verify_assign_state(td, data);
        } else
                ret = verify_load_state(td, "local");
 
@@ -2182,10 +2012,36 @@ mounted:
        return true;
 }
 
+static bool waitee_running(struct thread_data *me)
+{
+       const char *waitee = me->o.wait_for;
+       const char *self = me->o.name;
+       struct thread_data *td;
+       int i;
+
+       if (!waitee)
+               return false;
+
+       for_each_td(td, i) {
+               if (!strcmp(td->o.name, self) || strcmp(td->o.name, waitee))
+                       continue;
+
+               if (td->runstate < TD_EXITED) {
+                       dprint(FD_PROCESS, "%s fenced by %s(%s)\n",
+                                       self, td->o.name,
+                                       runstate_to_name(td->runstate));
+                       return true;
+               }
+       }
+
+       dprint(FD_PROCESS, "%s: %s completed, can run\n", self, waitee);
+       return false;
+}
+
 /*
  * Main function for kicking off and reaping jobs, as needed.
  */
-static void run_threads(void)
+static void run_threads(struct sk_out *sk_out)
 {
        struct thread_data *td;
        unsigned int i, todo, nr_running, m_rate, t_rate, nr_started;
@@ -2275,6 +2131,7 @@ reap:
                struct thread_data *map[REAL_MAX_JOBS];
                struct timeval this_start;
                int this_jobs = 0, left;
+               struct fork_data *fd;
 
                /*
                 * create threads (TD_NOT_CREATED -> TD_CREATED)
@@ -2305,6 +2162,12 @@ reap:
                                break;
                        }
 
+                       if (waitee_running(td)) {
+                               dprint(FD_PROCESS, "%s: waiting for %s\n",
+                                               td->o.name, td->o.wait_for);
+                               continue;
+                       }
+
                        init_disk_util(td);
 
                        td->rusage_sem = fio_mutex_init(FIO_MUTEX_LOCKED);
@@ -2318,15 +2181,20 @@ reap:
                        map[this_jobs++] = td;
                        nr_started++;
 
+                       fd = calloc(1, sizeof(*fd));
+                       fd->td = td;
+                       fd->sk_out = sk_out;
+
                        if (td->o.use_thread) {
                                int ret;
 
                                dprint(FD_PROCESS, "will pthread_create\n");
                                ret = pthread_create(&td->thread, NULL,
-                                                       thread_main, td);
+                                                       thread_main, fd);
                                if (ret) {
                                        log_err("pthread_create: %s\n",
                                                        strerror(ret));
+                                       free(fd);
                                        nr_started--;
                                        break;
                                }
@@ -2339,14 +2207,15 @@ reap:
                                dprint(FD_PROCESS, "will fork\n");
                                pid = fork();
                                if (!pid) {
-                                       int ret = fork_main(shm_id, i);
+                                       int ret;
 
+                                       ret = (int)(uintptr_t)thread_main(fd);
                                        _exit(ret);
                                } else if (i == fio_debug_jobno)
                                        *fio_debug_jobp = pid;
                        }
                        dprint(FD_MUTEX, "wait on startup_mutex\n");
-                       if (fio_mutex_down_timeout(startup_mutex, 10)) {
+                       if (fio_mutex_down_timeout(startup_mutex, 10000)) {
                                log_err("fio: job startup hung? exiting.\n");
                                fio_terminate_threads(TERMINATE_ALL);
                                fio_abort = 1;
@@ -2431,81 +2300,13 @@ reap:
        update_io_ticks();
 }
 
-static void wait_for_helper_thread_exit(void)
-{
-       void *ret;
-
-       helper_exit = 1;
-       pthread_cond_signal(&helper_cond);
-       pthread_join(helper_thread, &ret);
-}
-
 static void free_disk_util(void)
 {
        disk_util_prune_entries();
-
-       pthread_cond_destroy(&helper_cond);
-}
-
-static void *helper_thread_main(void *data)
-{
-       int ret = 0;
-
-       fio_mutex_up(startup_mutex);
-
-       while (!ret) {
-               uint64_t sec = DISK_UTIL_MSEC / 1000;
-               uint64_t nsec = (DISK_UTIL_MSEC % 1000) * 1000000;
-               struct timespec ts;
-               struct timeval tv;
-
-               gettimeofday(&tv, NULL);
-               ts.tv_sec = tv.tv_sec + sec;
-               ts.tv_nsec = (tv.tv_usec * 1000) + nsec;
-
-               if (ts.tv_nsec >= 1000000000ULL) {
-                       ts.tv_nsec -= 1000000000ULL;
-                       ts.tv_sec++;
-               }
-
-               pthread_cond_timedwait(&helper_cond, &helper_lock, &ts);
-
-               ret = update_io_ticks();
-
-               if (helper_do_stat) {
-                       helper_do_stat = 0;
-                       __show_running_run_stats();
-               }
-
-               if (!is_backend)
-                       print_thread_status();
-       }
-
-       return NULL;
-}
-
-static int create_helper_thread(void)
-{
-       int ret;
-
-       setup_disk_util();
-
-       pthread_cond_init(&helper_cond, NULL);
-       pthread_mutex_init(&helper_lock, NULL);
-
-       ret = pthread_create(&helper_thread, NULL, helper_thread_main, NULL);
-       if (ret) {
-               log_err("Can't create helper thread: %s\n", strerror(ret));
-               return 1;
-       }
-
-       dprint(FD_MUTEX, "wait on startup_mutex\n");
-       fio_mutex_down(startup_mutex);
-       dprint(FD_MUTEX, "done waiting on startup_mutex\n");
-       return 0;
+       helper_thread_destroy();
 }
 
-int fio_backend(void)
+int fio_backend(struct sk_out *sk_out)
 {
        struct thread_data *td;
        int i;
@@ -2535,14 +2336,14 @@ int fio_backend(void)
 
        set_genesis_time();
        stat_init();
-       create_helper_thread();
+       helper_thread_create(startup_mutex, sk_out);
 
        cgroup_list = smalloc(sizeof(*cgroup_list));
        INIT_FLIST_HEAD(cgroup_list);
 
-       run_threads();
+       run_threads(sk_out);
 
-       wait_for_helper_thread_exit();
+       helper_thread_exit();
 
        if (!fio_abort) {
                __show_run_stats();