On 9/20/23 14:52, Suzuki K Poulose wrote: > On 15/09/2023 10:36, Anshuman Khandual wrote: >> Cycle counting is enabled, when requested and supported but with a default >> threshold value ETM_CYC_THRESHOLD_DEFAULT i.e 0x100 getting into TRCCCCTLR, >> representing the minimum interval between cycle count trace packets. > > minor nit: > > When Cycle counting is enabled, we use a default threshold value (0x100) for the instruction trace cycle counting. >> >> This makes cycle threshold user configurable, from the user space via perf >> event attributes. Although it falls back using ETM_CYC_THRESHOLD_DEFAULT, >> in case no explicit request. > > Minor nit: > > This patch makes the cycle threshold user configurable via perf event > attributes( 'cc_threshold' => event->attr.config3[11:0] ), falling back > to the the current default if unspecified. > > > >> As expected it creates a sysfs file as well. > > >> >> /sys/bus/event_source/devices/cs_etm/format/cc_threshold >> >> New 'cc_threshold' uses 'event->attr.config3' as no more space is available >> in 'event->attr.config1' or 'event->attr.config2'. > > Trim the above part. > > > Rest looks fine to me. Will change the commit message as follows. coresight: etm: Make cycle count threshold user configurable When cycle counting is enabled, we use a default threshold value i.e 0x100 for the instruction trace cycle counting. This patch makes the cycle threshold user configurable via perf event attributes( 'cc_threshold' => event->attr.config3[11:0] ), falling back to the current default if unspecified.