On Aug 23, 2021 / 03:02, Damien Le Moal wrote:
> On 2021/08/23 10:35, Shinichiro Kawasaki wrote:
> [...]
> >>> diff --git a/thread_options.h b/thread_options.h
> >>> index 4b4ecfe1..6fe1cad7 100644
> >>> --- a/thread_options.h
> >>> +++ b/thread_options.h
> >>> @@ -189,6 +189,7 @@ struct thread_options {
> >>> unsigned int thinktime_spin;
> >>> unsigned int thinktime_blocks;
> >>> unsigned int thinktime_blocks_type;
> >>> + unsigned int thinktime_iotime;
> >>> unsigned int fsync_blocks;
> >>> unsigned int fdatasync_blocks;
> >>> unsigned int barrier_blocks;
> >>> @@ -500,6 +501,8 @@ struct thread_options_pack {
> >>> uint32_t thinktime_spin;
> >>> uint32_t thinktime_blocks;
> >>> uint32_t thinktime_blocks_type;
> >>> + uint32_t thinktime_iotime;
> >>> + uint32_t pad6;
> >>
> >> Why is this needed ? Some alignement warning ?
> >
> > Yes. Without the pad, I observe build errors as follows:
> >
> > In file included from fio.h:17,
> > from libfio.c:31:
> > libfio.c: In function ‘initialize_fio’:
> > compiler/compiler.h:31:44: error: static assertion failed: "percentile_list"
> > 31 | #define compiletime_assert(condition, msg) _Static_assert(condition, msg)
> > | ^~~~~~~~~~~~~~
> > libfio.c:372:9: note: in expansion of macro ‘compiletime_assert’
> > 372 | compiletime_assert((offsetof(struct thread_options_pack, percentile_list) % 8) == 0, "percentile_list");
> > | ^~~~~~~~~~~~~~~~~~
> > compiler/compiler.h:31:44: error: static assertion failed: "latency_percentile"
> > 31 | #define compiletime_assert(condition, msg) _Static_assert(condition, msg)
> > | ^~~~~~~~~~~~~~
> > libfio.c:373:9: note: in expansion of macro ‘compiletime_assert’
> > 373 | compiletime_assert((offsetof(struct thread_options_pack, latency_percentile) % 8) == 0, "latency_percentile");
> > | ^~~~~~~~~~~~~~~~~~
> > make: *** [Makefile:496: libfio.o] Error 1
> > make: *** Waiting for unfinished jobs....
> >
> >> If yes, have you tried moving
> >> this declaration in the struct ?
> >
> > Yes. I moved the new field thinktime_iotime to the end of struct
> > thread_options_pack then the errors were avoided. But I wanted
> > to place the new field at the same place as other thinktime related
> > fields. For that purpose, I needed to add the padding pad6. I tried to
> > utilize other pads such as pad2 or pad5, but it didn't work.
> >
> > To place the related fields at same place with padding, or to place the new
> > field at different place without padding, which way to go?
>
> I think that is a question for Jens...
>
> Jens,
>
> Which way do you prefer ?
Jens,
May I ask your comment on the new pad in the struct thread_options_pack? If the
new pad is not good, I will move the new field thinktime_iotime to the end of
the struct.
--
Best Regards,
Shin'ichiro Kawasaki
