syslet engine: smart batching
authorJens Axboe <jens.axboe@oracle.com>
Mon, 26 Feb 2007 09:44:22 +0000 (10:44 +0100)
committerJens Axboe <jens.axboe@oracle.com>
Mon, 26 Feb 2007 09:44:22 +0000 (10:44 +0100)
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
engines/syslet-rw.c
fio.h

index 2a3095d..4b1b263 100644 (file)
@@ -21,41 +21,29 @@ struct syslet_data {
        struct syslet_uatom **ring;
 
        struct syslet_uatom *head, *tail;
-       struct syslet_uatom **event_map;
-       unsigned int event_map_idx;
 };
 
 static void fio_syslet_complete_atom(struct thread_data *td,
                                     struct syslet_uatom *atom)
 {
        struct syslet_data *sd = td->io_ops->data;
+       struct syslet_uatom *last;
        struct io_u *io_u;
-       int i, end;
-
-       if (!sd->event_map_idx)
-               return;
 
        /*
-        * Find the start of the string of atoms for this sequence
+        * complete from the beginning of the sequence up to (and
+        * including) this atom
         */
-       for (end = sd->event_map_idx - 1; end >= 0; end--)
-               if (atom == sd->event_map[end])
-                       break;
-
-       if (end < 0 || atom != sd->event_map[end]) {
-               printf("didn't find atom\n");
-               return;
-       }
-
-       //printf("end=%d, total %d\n", end, sd->event_map_idx);
+       last = atom;
+       io_u = atom->private;
+       atom = io_u->req.head;
 
        /*
         * now complete in right order
         */
-       for (i = 0; i <= end; i++) {
+       do {
                long ret;
 
-               atom = sd->event_map[i];
                io_u = atom->private;
                ret = *atom->ret_ptr;
                if (ret > 0)
@@ -65,19 +53,14 @@ static void fio_syslet_complete_atom(struct thread_data *td,
 
                assert(sd->nr_events < td->iodepth);
                sd->events[sd->nr_events++] = io_u;
-       }
 
-       /*
-        * Move later completions to the front, if we didn't complete all
-        */
-       if (end == (int) sd->event_map_idx - 1)
-               sd->event_map_idx = 0;
-       else {
-               int nr = sd->event_map_idx - end - 1;
+               if (atom == last)
+                       break;
 
-               memmove(sd->event_map, &sd->event_map[end + 1], nr * sizeof(struct syslet_uatom *));
-               sd->event_map_idx = nr;
-       }
+               atom = atom->next;
+       } while (1);
+
+       assert(!last->next);
 }
 
 /*
@@ -201,7 +184,7 @@ static void cachemiss_thread_start(void)
 
 static unsigned long thread_stack_alloc()
 {
-       return (unsigned long)malloc(THREAD_STACK_SIZE) + THREAD_STACK_SIZE;
+       return (unsigned long) malloc(THREAD_STACK_SIZE) + THREAD_STACK_SIZE;
 }
 
 static int fio_syslet_commit(struct thread_data *td)
@@ -212,6 +195,8 @@ static int fio_syslet_commit(struct thread_data *td)
        if (!sd->head)
                return 0;
 
+       assert(!sd->tail->next);
+
        if (!sd->ahu.new_thread_stack)
                sd->ahu.new_thread_stack = thread_stack_alloc();
 
@@ -239,7 +224,7 @@ static int fio_syslet_queue(struct thread_data *td, struct io_u *io_u)
        } else
                sd->head = sd->tail = &io_u->req.atom;
 
-       sd->event_map[sd->event_map_idx++] = sd->tail;
+       io_u->req.head = sd->head;
        return FIO_Q_QUEUED;
 }
 
@@ -257,8 +242,8 @@ static int async_head_init(struct syslet_data *sd, unsigned int depth)
        sd->ahu.completion_ring = sd->ring;
        sd->ahu.ring_size_bytes = ring_size;
        sd->ahu.head_stack = thread_stack_alloc();
-       sd->ahu.head_eip = (unsigned long)cachemiss_thread_start;
-       sd->ahu.new_thread_eip = (unsigned long)cachemiss_thread_start;
+       sd->ahu.head_eip = (unsigned long) cachemiss_thread_start;
+       sd->ahu.new_thread_eip = (unsigned long) cachemiss_thread_start;
 
        return 0;
 }
@@ -275,7 +260,6 @@ static void fio_syslet_cleanup(struct thread_data *td)
        if (sd) {
                async_head_exit(sd);
                free(sd->events);
-               free(sd->event_map);
                free(sd);
                td->io_ops->data = NULL;
        }
@@ -290,8 +274,6 @@ static int fio_syslet_init(struct thread_data *td)
        memset(sd, 0, sizeof(*sd));
        sd->events = malloc(sizeof(struct io_u *) * td->iodepth);
        memset(sd->events, 0, sizeof(struct io_u *) * td->iodepth);
-       sd->event_map = malloc(sizeof(struct syslet_uatom *) * td->iodepth);
-       memset(sd->event_map, 0, sizeof(struct syslet_uatom *) * td->iodepth);
 
        /*
         * This will handily fail for kernels where syslet isn't available
diff --git a/fio.h b/fio.h
index f2366c4..57d1b6b 100644 (file)
--- a/fio.h
+++ b/fio.h
@@ -81,8 +81,9 @@ struct io_piece {
 
 #ifdef FIO_HAVE_SYSLET
 struct syslet_req {
-       struct syslet_uatom atom;
-       long ret;
+       struct syslet_uatom atom;       /* the atom to submit */
+       struct syslet_uatom *head;      /* head of the sequence */
+       long ret;                       /* syscall return value */
 };
 #endif