On 2014-10-24 20:35, Mark Kirkwood wrote:
Patched client machine *only* - re-running fio from there works fine with (default - i.e no [client' section at all) cache settings: $ fio read-test.fio rbd_thread: (g=0): rw=read, bs=4M-4M/4M-4M/4M-4M, ioengine=rbd, iodepth=32 fio-2.1.13-88-gb2ee7 Starting 1 process rbd engine: RBD version: 0.1.8 Jobs: 1 (f=1): [R(1)] [75.0% done] [1165MB/0KB/0KB /s] [291/0/0 iops] [eta 00m:0Jobs: 1 (f=1): [R(1)] [83.3% done] [447.4MB/0KB/0KB /s] [111/0/0 iops] [eta 00m:Jobs: 1 (f=1): [R(1)] [100.0% done] [268.0MB/0KB/0KB /s] [67/0/0 iops] [eta 00m:Jobs: 1 (f=1): [R(1)] [100.0% done] [336.1MB/0KB/0KB /s] [84/0/0 iops] [eta 00m:00s] rbd_thread: (groupid=0, jobs=1): err= 0: pid=5980: Sat Oct 25 15:32:16 2014 read : io=4096.0MB, bw=623410KB/s, iops=152, runt= 6728msec slat (usec): min=7, max=230691, avg=5664.46, stdev=14434.46 clat (msec): min=11, max=1589, avg=193.03, stdev=246.84 lat (msec): min=13, max=1606, avg=198.70, stdev=248.62 clat percentiles (msec): | 1.00th=[ 17], 5.00th=[ 30], 10.00th=[ 43], 20.00th=[ 60], | 30.00th=[ 78], 40.00th=[ 93], 50.00th=[ 109], 60.00th=[ 124], | 70.00th=[ 147], 80.00th=[ 210], 90.00th=[ 498], 95.00th=[ 758], | 99.00th=[ 1237], 99.50th=[ 1467], 99.90th=[ 1565], 99.95th=[ 1598], | 99.99th=[ 1598] bw (KB /s): min=178086, max=1193644, per=100.00%, avg=637349.58, stdev=397329.85 lat (msec) : 20=2.15%, 50=12.11%, 100=30.08%, 250=38.09%, 500=7.62% lat (msec) : 750=4.79%, 1000=2.64%, 2000=2.54% cpu : usr=1.69%, sys=0.28%, ctx=6234, majf=0, minf=78 IO depths : 1=0.1%, 2=0.2%, 4=0.4%, 8=1.7%, 16=58.6%, 32=39.1%, >=64=0.0% submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0% complete : 0=0.0%, 4=94.3%, 8=5.0%, 16=0.4%, 32=0.3%, 64=0.0%, >=64=0.0% issued : total=r=1024/w=0/d=0, short=r=0/w=0/d=0, drop=r=0/w=0/d=0 latency : target=0, window=0, percentile=100.00%, depth=32 Run status group 0 (all jobs): READ: io=4096.0MB, aggrb=623410KB/s, minb=623410KB/s, maxb=623410KB/s, mint=6728msec, maxt=6728msec
Since you're running rbd tests... Mind giving this patch a go? I don't have an easy way to test it myself. It has nothing to do with this issue, it's just a potentially faster way to do the rbd completions.
-- Jens Axboe
diff --git a/engines/rbd.c b/engines/rbd.c index 6fe87b8d010c..6aa96a5ff550 100644 --- a/engines/rbd.c +++ b/engines/rbd.c @@ -11,6 +11,7 @@ struct fio_rbd_iou { struct io_u *io_u; + rbd_completion_t completion; int io_complete; }; @@ -221,34 +222,66 @@ static struct io_u *fio_rbd_event(struct thread_data *td, int event) return rbd_data->aio_events[event]; } -static int fio_rbd_getevents(struct thread_data *td, unsigned int min, - unsigned int max, const struct timespec *t) +static inline int fri_check_complete(struct rbd_data *rbd_data, + struct io_u *io_u, + unsigned int *events) +{ + struct fio_rbd_iou *fri = io_u->engine_data; + + if (fri->io_complete) { + fri->io_complete = 0; + rbd_data->aio_events[*events] = io_u; + (*events)++; + return 1; + } + + return 0; +} + +static int rbd_iter_events(struct thread_data *td, unsigned int *events, + unsigned int min_evts, int wait) { struct rbd_data *rbd_data = td->io_ops->data; - unsigned int events = 0; + unsigned int this_events = 0; struct io_u *io_u; int i; - struct fio_rbd_iou *fov; - do { - io_u_qiter(&td->io_u_all, io_u, i) { - if (!(io_u->flags & IO_U_F_FLIGHT)) - continue; + io_u_qiter(&td->io_u_all, io_u, i) { + if (!(io_u->flags & IO_U_F_FLIGHT)) + continue; - fov = (struct fio_rbd_iou *)io_u->engine_data; + if (fri_check_complete(rbd_data, io_u, events)) + this_events++; + else if (wait) { + struct fio_rbd_iou *fri = io_u->engine_data; - if (fov->io_complete) { - fov->io_complete = 0; - rbd_data->aio_events[events] = io_u; - events++; - } + rbd_aio_wait_for_complete(fri->completion); + if (fri_check_complete(rbd_data, io_u, events)) + this_events++; } - if (events < min) - usleep(100); - else + if (*events >= min_evts) + break; + } + + return this_events; +} + +static int fio_rbd_getevents(struct thread_data *td, unsigned int min, + unsigned int max, const struct timespec *t) +{ + unsigned int this_events, events = 0; + int wait = 0; + + do { + this_events = rbd_iter_events(td, &events, min, wait); + + if (events >= min) break; + if (this_events) + continue; + wait = 1; } while (1); return events; @@ -258,7 +291,7 @@ static int fio_rbd_queue(struct thread_data *td, struct io_u *io_u) { int r = -1; struct rbd_data *rbd_data = td->io_ops->data; - rbd_completion_t comp; + struct fio_rbd_iou *fri = io_u->engine_data; fio_ro_check(td, io_u); @@ -266,7 +299,7 @@ static int fio_rbd_queue(struct thread_data *td, struct io_u *io_u) r = rbd_aio_create_completion(io_u, (rbd_callback_t) _fio_rbd_finish_write_aiocb, - &comp); + &fri->completion); if (r < 0) { log_err ("rbd_aio_create_completion for DDIR_WRITE failed.\n"); @@ -274,7 +307,8 @@ static int fio_rbd_queue(struct thread_data *td, struct io_u *io_u) } r = rbd_aio_write(rbd_data->image, io_u->offset, - io_u->xfer_buflen, io_u->xfer_buf, comp); + io_u->xfer_buflen, io_u->xfer_buf, + fri->completion); if (r < 0) { log_err("rbd_aio_write failed.\n"); goto failed; @@ -284,7 +318,7 @@ static int fio_rbd_queue(struct thread_data *td, struct io_u *io_u) r = rbd_aio_create_completion(io_u, (rbd_callback_t) _fio_rbd_finish_read_aiocb, - &comp); + &fri->completion); if (r < 0) { log_err ("rbd_aio_create_completion for DDIR_READ failed.\n"); @@ -292,7 +326,8 @@ static int fio_rbd_queue(struct thread_data *td, struct io_u *io_u) } r = rbd_aio_read(rbd_data->image, io_u->offset, - io_u->xfer_buflen, io_u->xfer_buf, comp); + io_u->xfer_buflen, io_u->xfer_buf, + fri->completion); if (r < 0) { log_err("rbd_aio_read failed.\n"); @@ -303,14 +338,14 @@ static int fio_rbd_queue(struct thread_data *td, struct io_u *io_u) r = rbd_aio_create_completion(io_u, (rbd_callback_t) _fio_rbd_finish_sync_aiocb, - &comp); + &fri->completion); if (r < 0) { log_err ("rbd_aio_create_completion for DDIR_SYNC failed.\n"); goto failed; } - r = rbd_aio_flush(rbd_data->image, comp); + r = rbd_aio_flush(rbd_data->image, fri->completion); if (r < 0) { log_err("rbd_flush failed.\n"); goto failed;