Re: [PATCH 1/1] perf symbols: Allow lookups by symbol name too

From: Frederic Weisbecker
Date: Mon Dec 14 2009 - 06:21:43 EST


On Fri, Dec 11, 2009 at 06:50:22PM -0200, Arnaldo Carvalho de Melo wrote:
> From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
>
> Configurable via symbol_conf.sort_by_name, so that the cost of an extra
> rb_node on all 'struct symbol' instances is not paid by tools that only
> want to decode addresses.
>
> How to use it:
>
> symbol_conf.sort_by_name = true;
> symbol_init(&symbol_conf);
>
> struct map *map = map_groups__find_by_name(kmaps, MAP__VARIABLE, "[kernel.kallsyms]");
>
> if (map == NULL) {
> pr_err("couldn't find map!\n");
> kernel_maps__fprintf(stdout);
> } else {
> struct symbol *sym = map__find_symbol_by_name(map, sym_filter, NULL);
> if (sym == NULL)
> pr_err("couldn't find symbol %s!\n", sym_filter);
> else
> pr_info("symbol %s: %#Lx-%#Lx \n", sym_filter, sym->start, sym->end);
> }
>
> Looking over the vmlinux/kallsyms is common enough that I'll add a
> variable to the upcoming struct perf_session to avoid the need to use
> map_groups__find_by_name to get the main vmlinux/kallsyms map.
>
> The above example looks on the 'variable' symtab, but it is just like
> that for the functions one.
>
> Also the sort operation is done when we first use
> map__find_symbol_by_name, in a lazy way.



Thanks a lot. I'll give it a try soon :)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/