Messages in this thread | | | From | Namhyung Kim <> | Date | Tue, 11 Nov 2014 13:24:38 +0900 | Subject | Re: [PATCH 1/3] perf tools: Allow vmlinux to fallback to kallsyms on NO_LIBELF=1 |
| |
Hi Peter,
On Mon, Nov 10, 2014 at 9:11 PM, Peter Zijlstra <peterz@infradead.org> wrote: > On Mon, Nov 10, 2014 at 03:33:11PM +0900, Namhyung Kim wrote: >> Hmm.. I don't think it's specific to the minimal elf parser. The return >> value of dso__load_sym() is a number of symbols found so when it sees a >> dso with 0 symbols it'll fall back to the next option IMHO (not >> tested). Did you see a problem with the current code? > > So your patch: > > +++ b/tools/perf/util/symbol-minimal.c > @@ -335,6 +335,9 @@ int dso__load_sym(struct dso *dso, struct map *map __maybe_unused, > unsigned char *build_id[BUILD_ID_SIZE]; > int ret; > > + if (dso->kernel) > + return 0; /* always use kallsyms */ > + > > changes the symbol-minimal.c file to add this exception. That is very > much specific to the minimal elf parser, or am I just seeing things?
What minimal parser does here is just skip kernel dsos (vmlinux) since it didn't deal with all the details of parsing vmlinux currently.
> > What I was saying, why not have a util/symbol.c change that disregards > all DSOs with 0 symbols in.
The util/symbol.c doesn't need this because it can handle vmlinux reliably. So after reading symbol table, it'll use the dso if it actually contains symbols or fallback to next dso if it has 0 symbols. IOW it already disregards all dsos with 0 symbols in.
-- Thanks, Namhyung
| |