Messages in this thread | | | Date | Mon, 22 Jun 2015 12:53:49 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [RFC] perf report: introduce --map-anon-mem for anon-executable-memory symbols parsing |
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Em Mon, Jun 22, 2015 at 11:22:13PM +0800, Hou Pengyang escreveu: > On 2015/6/19 18:42, Ingo Molnar wrote: > > > >* Wangnan (F) <wangnan0@huawei.com> wrote: > > > >>On 2015/6/18 22:01, Hou Pengyang wrote: > >>>This patch introduces a --map-anon-mem argument to perf report to deal > >>>with anon-executable-memory symbol parsing. > >> > >>--map-anon-mem is not a good name. The user defined map area list > >>introduced in this patch can be used on not only anon mapping but > >>also file mapping. > > > >Yeah, so quirky options generally suck and only 0.01% of the users will use it. > >It's in a way worse than not having this code, because we'll have to maintain it, > >but it won't be used. > > > >Is there a way to auto-detect 'executable anon mappings' (perhaps by generating an > >MMAP event with some extra bit set, or a new MMAP event?) so that it's all > >seemless? > > > I think it not difficult to generate such MMAP event, just like : > > 0 435090424309600 0x3e0 [0x68]: PERF_RECORD_MMAP2 > 788/788:[0x7f946c0000(0x4000) @ 0x7f946c0000 00:00 0 0]: ---p //anon > > But for symbol parsing, this is not enough. For such mmap area, perf > doesn't know the path of '.so/.o', which is necessarcy for symbol- > parsing. So we need to tell perf the relationship between the .so file and > the mmap range explicitly.
What is done to provide maps for JIT is detailed at:
tools/perf/Documentation/jit-interface.txt
Are you sure that can't be used for you guys? Its already automagically done, you just have to provide a file for that pid with the mappings.
Sure, it is not for ELF, but that could be easily done, just autodetect the map type.
- Arnaldo
> Thanks, > Hou > > >The user should not be required to know about such details! > > > >Thanks, > > > > Ingo > >-- > >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/ > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/
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