Messages in this thread | | | Date | Thu, 13 Nov 2014 00:25:57 +0900 | From | Masami Hiramatsu <> | Subject | Re: [RFC] perf-cache command interface design |
| |
(2014/11/11 22:10), Arnaldo Carvalho de Melo wrote: > Em Tue, Nov 11, 2014 at 03:53:42PM +0900, Masami Hiramatsu escreveu: >> (2014/11/10 21:23), Arnaldo Carvalho de Melo wrote: >>> Em Mon, Nov 10, 2014 at 07:59:24PM +0900, Masami Hiramatsu escreveu: >>>> Here is the second try for the probe-cache. This version simplifies >>>> the synopsis, and unifies the SDT and probe caches. >>>> Please give me your comments/ideas! >>>> >>>> Command-line Synopsis >>>> ===================== > >>>> Add elf(or symbols) and probe-caches of SDT if exists in <FILES> >>>> perf cache --add <FILES> [--probe <SPEC>] # for user programs > >>> Why the --probe above? Shouldn't this be just (if you are talking about >>> ELF files only): > >>> perf cache --add <FILES> > >> Yes, for the elf and sdt cache, we don't need --probe. >> Note that "[]" means optional. If we would like to add some probe cache, >> we need a spec of probe definition. > > I understand that, its just that it looked superfluous at that specific > place, where you are explaining how to add ELF files. > >>>> perf cache --kcore <FILE> [--probe <SPEC>] # for kcore ? > >>> Adrian, aren't kcore files easily identifiable as such and thus could be >>> added as: > >>> perf cache --add <FILES> > >>>> perf cache --probe <SPEC> # for the current kernel > >>> Why do we need a --probe here? Don't they always start with a character >>> that is seldomly used in ELF file names and thus we could get away with >>> not requiring --probe? > >> This is only for adding the probe cache (not elf, nor sdt), which requires >> a probe definition. Moreover, I'd like to unify the specification of the >> probe definition with perf-probe. In that case, --probe is more natural. > > What I meant was, what is wrong with replacing: > > perf cache --probe <SPEC> # for the current kernel > > With: > > perf cache --add <PROBE-SPEC> # for the current kernel > > And have it figure out that what is being added is a probe and do the > right thing?
As I've said previously, PROBE-SPEC can be same as FILES (imagine that a binary file which has same name function in the kernel.) Moreover, PROBE-SPEC requires the target binary(or kernel module) except for kernel probes. In that case, anyway we need -x or -m options with file-path for --add, that is very strange.
e.g.
For me,
perf cache --add ./binary --probe '*'
looks more natural than
perf cache --add '*' -exec ./binary
since in other cases(sdt/elf), we'll just do
perf cache --add ./binary
:-/
>>>> Remove caches related to <FILES> or <BUILDIDS> >>>> perf cache --remove <FILES>|<BUILDIDS> >>>> >>>> Show all probe caches(including SDT) or buildids >>>> perf cache --list [probe|buildid] >>>> >>>> Delete existing probe-cache entries for kernel, <PATH> or/and <BUILDID>. >>>> perf cache --probe-del [<GROUP>:]<EVENT>[@<PATH>][#<BUILDID>] >>> >>> Ditto, i.e. can't we just use: >>> >>> perf cache --remove [<GROUP>:]<EVENT>[@<PATH>][#<BUILDID>] >>> >>> And it figure out that this is a probe that is being removed? >> >> In most cases, it may be OK, but it is also possible to cause unexpected >> result when mis-typing. I think if <FILE> is always starting at '/', it >> is easy to identify. > > We can keep the explicit switch (--probe-del) perhaps to resolve > ambiguities, if they happen, but make it so that it is not strictly > required for the common case.
OK, it'll take a longer time to remove, since we need to load all caches to find matching entries of probe caches, but is feasible.
Thank you!
-- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com
-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |