Em Mon, Oct 02, 2017 at 03:14:05PM +0100, Will Deacon escreveu: > On Fri, Sep 29, 2017 at 05:19:40PM -0500, Kim Phillips wrote: > > On Thu, 28 Sep 2017 15:09:50 +0100 > > Will Deacon <[email protected]> wrote: > > > + if (arm_spe_event_to_pmsevfr(event) & SYS_PMSEVFR_EL1_RES0) > > > + return -EOPNOTSUPP; > > > + if (attr->exclude_idle) > > > + return -EOPNOTSUPP;
> > "PMU Hardware doesn't support sampling/overflow-interrupts." will be > > printed if the user didn't specify a sample period. Otherwise, a > > string with "/bin/dmesg may provide additional information." will be > > printed. > > I was hoping for a response from acme by now for this: > > https://www.spinics.net/lists/linux-perf-users/msg04066.html > > Alas, nothing. Looking at the #ifdef x86 in evsel.c, I'm guessing > > it'll be ok, although I'm still not sure how PMU-specific we can get in > > evsel.c, nor whether it's ok to communicate lists of h/w supported > > sample periods through /sys/bus/event_source/devices/... > > > > acme? OK to refactor evsel messaging for Arm, including parsing for > > which PMUs are being used, so customize the message? > > Arnaldo's probably got enough on his plate maintaining perf tool, so my > advice would be to post a patch as an RFC and use that as a concrete basis > for discussion. It often works out better starting with code, even if none > of it ends up getting merged (and you can include bits of your email above > in the cover letter). I'm all for more informative messages, and if you guys agree on how to provide the info in a way that combined with logic in evsel.c, I'd say do what Will suggested, post a patch series and include usage examples, before and after. - Arnaldo
