On Thu, Sep 27, 2012 at 4:16 PM, Namhyung Kim <namhy...@kernel.org> wrote: > On Thu, 27 Sep 2012 14:25:10 +0300, Irina Tirdea wrote: >>>> The perf built to run on the host needs to use arm-eabi-objdump from >>>> the toolchain so that it can analyse data recorded on Android. This >>>> patch is targeting this scenario, not the previous one. In this case, >>>> the CROSS_COMPILE option would be different than arm-eabi- so using >>>> $(CROSS_COMPILE)objdump would be wrong. objdump should be overridden >>>> when running make since there is no connection between the toolchain >>>> used here and the path for objdump. I am always overriding objdump >>>> when calling make, so I did not catch this. >>>> >>>> I think that I should change DEFAULT_OBJDUMP_PATH=objdump in the >>>> Makefile to handle the first scenario. I'll also explain this in the >>>> commit message so that it is more clear and make the same change for >>>> the addr2line patch. >>>> >>>> What do you think? >>> >>> I think the right thing to do is finding a correct objdump at runtime in >>> some way. Why do you want to make it compile-time configurable? >>> >> >> The correct objdump path can be detected at runtime by setting the >> toolchain path. But since the name is arm-eabi-objdump and not >> objdump, it does not know to use it instead. >> >> The only way (I can think of) to change objdump at runtime would be to >> use the --objdump option for perf annotate (and provide a similar >> option for addr2line). The problem with this approach is that the user >> has to be aware that perf annotate uses the objdump tool and that he >> has to use the cross-compiler version instead. Since the user will >> have perf compiled for host as part of his Android tree, he will >> expect it to work without these further changes from his part. The >> path for objdump can be set in the Android Makefile at compile time so >> that the user doesn't need to be aware of it. > > What I'm thinking is that perf can try to find cross-built binutils when > it detects perf.data file is came from other machine/architecture. > Fortunately perf_session_env was added recently and it has the arch > information from the file so we can use it to find the path. > > Following patch is a proof-of-concept patch and only build tested. > What do you think? Could you play with it for some time? :) >
Thanks, this looks like the right approach. :) I'm going to test it for Android cross-compiling and submit an update if needed. Thanks, Irina -- 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/
