On 2015/07/21 0:52, Namhyung Kim wrote: > On Mon, Jul 20, 2015 at 12:19:14PM +0900, Masami Hiramatsu wrote: >> On 2015/07/19 19:46, Namhyung Kim wrote: >>> On Wed, Jul 15, 2015 at 06:15:37PM +0900, Masami Hiramatsu wrote: >>>> perf buildid-cache --add <binary> scans given binary and add >>>> the SDT events to probe cache. It is possible to use the cached >>>> SDT events as other cached events (perf probe <provider>:<event>=<event>). >>> >>> That means lookup the cached SDT events only using event name, right? >> >> Right, >> >>> What if same event names are used by more than one providers? >> >> That's a good discussion point :) >> >> What I'm thinking is that the real SDT is always prior to other >> cached events. (currently not implemented yet) >> - if someone gives a same event name, it overwrites previous one. >> - if someone gives an event name same as existing SDT, it is not >> cached (or rejected) >> - if SDT scanned after cached same name events, SDT always overwrites >> the entry. > > I'm thinking about allowing same name for different events. IMHO it's > possible to have same SDT names for some reason - i.e. having multiple > versions of same program, similar (but different) binaries have same > event names, or even in a single bianry it might have same event names > but different provider names. > > In that case, I think perf probe (or record) simply can do the job for > every matching events.
Hmm, right. If we support the 3-level event name as you said, that can make things much simpler. We can use "probe_<12chars-buildid>" for the toplevel dirname, and "provider/name" for lower 2 levels. Or, if we can use <provider>.<buildid>/ for the group name (this requres kernel change) it is more easier to support SDTs. Thank you, > >> >> So, the all SDT events will be treated as fixed events. >> >> Note that this will be happen if we agree SDT and probe share the >> same namespace :) > > Right. > > Thanks, > Namhyung > > -- Masami HIRAMATSU Linux Technology Research Center, System Productivity Research Dept. Center for Technology Innovation - Systems Engineering Hitachi, Ltd., Research & Development Group E-mail: masami.hiramatsu...@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
