> -----Original Message----- > From: Jens Axboe [mailto:axboe@xxxxxxxxx] > Sent: Wednesday, September 03, 2014 8:34 PM > To: Elliott, Robert (Server Storage); fio@xxxxxxxxxxxxxxx; > scameron@xxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH] fio: fix hangs due to iodepth_low > > On 2014-09-03 18:23, Robert Elliott wrote: > > With some combinations of iodepth, iodepth_batch, > iodepth_batch_complete, > > and io_depth_low, do_io hangs after reaping the first set of > completions > > since io_u_queued_complete is called requesting more completions than > > td->cur_depth. > > > > Example printing min_evts and td->cur_depth in the do/while loop: > > waiting on min=96 cd=627 > > waiting on min=96 cd=531 > > waiting on min=96 cd=435 > > waiting on min=96 cd=339 > > waiting on min=96 cd=243 > > waiting on min=96 cd=147 > > waiting on min=96 cd=51 > > Jobs: 12 (f=12): [r(12)] [43.8% done] [0KB/0KB/0KB /s] [0/0/0 iops] > [eta 00m:09s] > > ... > > Jobs: 12 (f=12): [r(12)] [0.0% done] [0KB/0KB/0KB /s] [0/0/0 iops] > [eta 2863d:18h:28m:38s] > > <fio never exits> > > > > Fix this by adjusting min_evts to the current_depth if that is > smaller. > > > > Tested with a jobfile including: > > iodepth=1011 > > iodepth_batch=96 > > iodepth_batch_complete=96 > > iodepth_low=1 > > runtime=15 > > time_based > > > > Made the same change to do_verify, but not tested there. > > > > Signed-off-by: Robert Elliott <elliott@xxxxxx> > > --- > > backend.c | 4 ++++ > > 1 files changed, 4 insertions(+), 0 deletions(-) > > > > diff --git a/backend.c b/backend.c > > index 7cb0a39..ce97f6d 100644 > > --- a/backend.c > > +++ b/backend.c > > @@ -606,6 +606,8 @@ reap: > > * and do the verification on them through > > * the callback handler > > */ > > + if (min_events < td->cur_depth) > > + min_events = td->cur_depth; > > Did you reverse these? From the description and debug output, seems it > should be: > > if (min_events > td->cur_depth) > min_events = td->cur_depth; > > and we should probably put this logic in io_u_queued_complete(), I think > that would be a safer alternative instead of near the callers. > > -- > Jens Axboe Sorry, yes - I didn't put it back right after adding code to inject the error. I will send an updated patch tomorrow putting the check into io_u_queued_complete (if that has access to td). ��.n��������+%������w��{.n�������^n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�
