> On 2021-03-31 14:35, Avri Altman wrote: > >> On 2021-03-31 11:34, Bart Van Assche wrote: > >> > On 3/30/21 8:14 PM, Can Guo wrote: > >> >> It works like: > >> >> /sys/bus/platform/drivers/ufshcd/*/monitor # echo 4096 > > >> >> monitor_chunk_size > >> >> /sys/bus/platform/drivers/ufshcd/*/monitor # echo 1 > > monitor_enable > >> >> /sys/bus/platform/drivers/ufshcd/*/monitor # grep ^ /dev/null * > >> >> monitor_chunk_size:4096 > >> >> monitor_enable:1 > >> >> read_nr_requests:17 > >> >> read_req_latency_avg:169 > >> >> read_req_latency_max:594 > >> >> read_req_latency_min:66 > >> >> read_req_latency_sum:2887 > >> >> read_total_busy:2639 > >> >> read_total_sectors:136 > >> >> write_nr_requests:116 > >> >> write_req_latency_avg:440 > >> >> write_req_latency_max:4921 > >> >> write_req_latency_min:23 > >> >> write_req_latency_sum:51052 > >> >> write_total_busy:19584 > >> >> write_total_sectors:928 > >> > > >> > Are any of these attributes UFS-specific? If not, isn't this > >> > functionality that should be added to the block layer instead of to the > >> > UFS driver? > >> > > >> > >> Hi Bart, > >> > >> I didn't think that before because we've already have the powerful > >> "blktrace" > >> tool to collect the overall statistics of each layer. > >> > >> I add this because I find it really come handy when > >> debug/analyze/profile > >> UFS driver/HW performance. And there will be UFS-specific nodes to be > >> added later to monitor statistics like UFS scaling, gating, doorbell, > >> write > >> booster, HPB and etc. > > We are using a designated analysis tool (web-based, a lot of fancy > > graphs etc.) that relies on ftrace - upiu tracer etc. > > Once the raw data is there - the options/insights are endless. > > > > Hi Avri, > > Yeah, one can dig out a lot of info from ftrace/systrace raw data. > But, most important, ftrace/systrace has below disadvantages > > [1] Enabling UFS/SCSI ftrace itself can impact UFS performance (a lot) > as per our profiling > [2] One needs a parser tool (only if they have one) to get the wanted > results > > So we usually use ftrace to analyze some sequences, e.g., cmd-response, > suspend-resume, gating and scaling, but not quite suitable for analyzing > performance, see [1]. > > These nodes provide us a swift method to look into statistics during > runtime [2]. > > Please let me know if you have any concerns w.r.t the change. No - not really. It's just this sort of things tend to grow... Thanks, Avri > > Thanks, > > Can Guo. > > > Thanks, > > Avri > >> > >> Thanks. > >> > >> Can Guo. > >> > >> > Thanks, > >> > > >> > Bart.
