On 9/13/22 10:07 AM, Vincent Fu wrote:
> On 9/13/22 06:45, Ankit Kumar wrote:
>> number_ios should be twice for trimwrite, just like size or
>> io_size. Update the documentation for "rw=trimwrite" to explain the
>> changes.
>>
>> Signed-off-by: Ankit Kumar <ankit.kumar@xxxxxxxxxxx>
>> ---
>> HOWTO.rst | 6 +++++-
>> backend.c | 6 ++++--
>> fio.1 | 5 ++++-
>> 3 files changed, 13 insertions(+), 4 deletions(-)
>>
>> diff --git a/HOWTO.rst b/HOWTO.rst
>> index 2c6c6dbe..924f5ed9 100644
>> --- a/HOWTO.rst
>> +++ b/HOWTO.rst
>> @@ -1129,7 +1129,11 @@ I/O type
>> Random mixed reads and writes.
>> **trimwrite**
>> Sequential trim+write sequences. Blocks will be trimmed first,
>> - then the same blocks will be written to.
>> + then the same blocks will be written to. So if ``io_size=64K``
>> + is specified, Fio will trim a total of 64K bytes and also
>> + write 64K bytes on the same trimmed blocks. This behaviour
>> + will be consistent with ``number_ios`` or other Fio options
>> + limiting the total bytes or number of I/O's.
>> Fio defaults to read if the option is not specified. For the mixed I/O
>> types, the default is to split them 50/50. For certain types of I/O the
>> diff --git a/backend.c b/backend.c
>> index fe614f6e..ec535bcc 100644
>> --- a/backend.c
>> +++ b/backend.c
>> @@ -971,9 +971,11 @@ static void do_io(struct thread_data *td, uint64_t *bytes_done)
>> total_bytes += td->o.size;
>> /* In trimwrite mode, each byte is trimmed and then written, so
>> - * allow total_bytes to be twice as big */
>> - if (td_trimwrite(td))
>> + * allow total_bytes or number of ios to be twice as big */
>> + if (td_trimwrite(td)) {
>> total_bytes += td->total_io_size;
>> + td->o.number_ios *= 2;
>> + }
>> while ((td->o.read_iolog_file && !flist_empty(&td->io_log_list)) ||
>> (!flist_empty(&td->trim_list)) || !io_issue_bytes_exceeded(td) ||
>> diff --git a/fio.1 b/fio.1
>> index 67d7c710..c67bd464 100644
>> --- a/fio.1
>> +++ b/fio.1
>> @@ -900,7 +900,10 @@ Random mixed reads and writes.
>> .TP
>> .B trimwrite
>> Sequential trim+write sequences. Blocks will be trimmed first,
>> -then the same blocks will be written to.
>> +then the same blocks will be written to. So if `io_size=64K' is specified,
>> +Fio will trim a total of 64K bytes and also write 64K bytes on the same
>> +trimmed blocks. This behaviour will be consistent with `number_ios' or
>> +other Fio options limiting the total bytes or number of I/O's.
>> .RE
>> .P
>> Fio defaults to read if the option is not specified. For the mixed I/O
>
> This is the right behavior because io_size and number_ios should be consistent. But this will require folks who have worked around the inconsistent behavior to adjust. I'll let Jens make the final call on this one.
>
> Reviewed-by: Vincent Fu <vincent.fu@xxxxxxxxxxx>
For cases like this, I do still prefer to fix it up so that it's consistent.
--
Jens Axboe
