Hi Kan, On Tue, 4 Nov 2014 17:07:43 +0000, Kan Liang wrote: > Hi Namhyung, > >> > tchain_edit [.] f1 >> > 0.14% 3.913444 tchain_edit [.] f2 >> > 99.82% 1.005478 tchain_edit [.] f3 >> >> Hmm.. I think it should be a default behavior for perf diff, otherwise -s >> symbol is almost meaningless IMHO. > > I think we need both instruction level and function level diff. > For debugging scaling issue, I think we need to do deeper analysis for some > cache or lock issue. The function level is too high granularity. > > The new option can be used to debug scaling regression issue. > If the binary/kernel is updated, it doesn't make sense to compare the > symbol address, since it should be changed. So comparing the function > should be more useful. > > >> What about setting the >> sort_sym.se_collapse in data_process() so that hists__match() can use >> symbol names? > > Yes, we can set it if we only do function level diff. But I'd like to keep > both. So I defined two sort keys. > "symbol" means "symbol address executed at the time of sample " > "symbol_name" means "name of function executed at the time of sample"
Hmm.. I don't think the symbol sort key provides the instruction level diff that you want. If it finds a symbol it just use the start address of the symbol, not the exact address of the sample. Am I missing something? Thanks, Namhyung -- 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/
