On Mon, Apr 12, 2021 at 7:35 AM Jinpu Wang <jinpu.wang@xxxxxxxxx> wrote: > > On Fri, Apr 9, 2021 at 11:03 PM Jens Axboe <axboe@xxxxxxxxx> wrote: > > > > On 4/9/21 10:03 AM, Md Haris Iqbal wrote: > > > Hi Jens, > > > > > > This version fixes the long lines in the code as per Christoph's comment. > > > > I'd really like to see some solid justification for the addition, > > though. I clicked the v1 link and it's got details on what you get out > > of it, but not really the 'why' of reasoning for the feature. I mean, > > you could feasibly have a blktrace based userspace solution. Just > > wondering if that has been tried, I know that's what we do at Facebook > > for example. > > > Hi Jens, > > Thanks for the reply. > For the use case of the additional stats, as a cloud provider, we > often need to handle report from the customers regarding > performance problem in a period of time in the past, so it's not > feasible for us to run blktrace, customer workload could change from > time to time, with the additional stats, we gather through all metrics > using Prometheus, we can navigate to the period of time interested, > to check if the performance matches the SLA, it also helps us to find > the user IO pattern, we can more easily reproduce. > > We do use blktrace from time to time too if it's not too late (when IO > pattern has not changed.) > > Thanks! > Jack Hi Jens, A gentle ping!
