On 2020/10/06 13:37, Krishna Kanth Reddy wrote: > On Tue, Sep 29, 2020 at 04:32:09PM +0000, Damien Le Moal wrote: >> On 2020/09/29 22:03, Krishna Kanth Reddy wrote: >>> 1. Added a new FIO option zone_open. >>> When it is enabled, Zones will be opened explicitly before sending I/Os. >>> 2. Add support for open_zones in libzbc I/O engine >>> 3. t/zbd: Add support to verify Zone Explicit Open >>> >>> This is a RFC. >>> Feedback / Comments will help in improving this further. >> >> My main question is why ? There is no performance benefit on the drive side from >> doing explicit zone open. On the contrary, performance may go down due to the >> added command overhead. So why do this ? What is your goal ? >> >> Using the max_open_zones=N option, fio writes will be limited to a set of N >> zones, implicitly open, until the zones are full (not open anymore) and new >> zones chosen (becoming implicitly open with writes). Adding explicit zone open >> will not give you anything more with this option used. And if you do not use it, >> performance with random writes will significantly go down. >> >> So please try to give convincing reasons for this. >> > It is a building block for future TPs. Which one ? Without that justification, I do not see the point of introducing this change right now. > We would like to do the pre-work and add the right option abstraction. > Zone open is 'implicit' by default. > Hence there won't be a performance drop with the newly added code. Sure, but there will be a drop for regular zone block devices with some workloads when that option is used. So if explicit zone open is needed by some future TP feature, it may be better to integrate explicit open with that feature rather than making it a generic fio option that users may mistakenly enable and end up wondering why they see lower performance with their device... > >>> >>> Ankit Kumar (2): >>> Add support for Explicit open zones >>> Add support for open_zones in libzbc I/O engine. >>> >>> Krishna Kanth Reddy (1): >>> t/zbd: Add support to verify Zone Explicit Open >>> >>> HOWTO | 13 ++++++++ >>> engines/libzbc.c | 42 +++++++++++++++++++++++++ >>> engines/skeleton_external.c | 12 ++++++++ >>> fio.1 | 11 +++++++ >>> ioengines.h | 2 ++ >>> options.c | 20 ++++++++++++ >>> oslib/blkzoned.h | 7 +++++ >>> oslib/linux-blkzoned.c | 26 ++++++++++++++++ >>> t/zbd/test-zbd-support | 27 ++++++++++++++++ >>> thread_options.h | 7 +++++ >>> zbd.c | 61 +++++++++++++++++++++++++++++++++++++ >>> 11 files changed, 228 insertions(+) >>> >> >> >> -- >> Damien Le Moal >> Western Digital Research >> -- Damien Le Moal Western Digital Research
