Re: [PATCH v7 11/18] perf tools: add mem access sampling core support

From: Jiri Olsa
Date: Wed Mar 27 2013 - 10:14:47 EST


On Thu, Jan 24, 2013 at 04:10:35PM +0100, Stephane Eranian wrote:

SNIP

>
> +static void ip__resolve_data(struct machine *self, struct thread *thread,
> + u8 m,
> + struct addr_map_symbol *ams,
> + u64 addr)
> +{
> + struct addr_location al;
> +
> + memset(&al, 0, sizeof(al));
> +
> + thread__find_addr_location(thread, self, m, MAP__VARIABLE, addr, &al,
> + NULL);
> + ams->addr = addr;
> + ams->al_addr = al.addr;
> + ams->sym = al.sym;
> + ams->map = al.map;
> +}
> +
> +struct mem_info *machine__resolve_mem(struct machine *self,
> + struct thread *thr,
> + struct perf_sample *sample,
> + u8 cpumode)
> +{
> + struct mem_info *mi;
> +
> + mi = calloc(1, sizeof(struct mem_info));
> + if (!mi)
> + return NULL;
> +
> + ip__resolve_ams(self, thr, &mi->iaddr, sample->ip);
> + ip__resolve_data(self, thr, cpumode, &mi->daddr, sample->addr);

question, should this be the other way around? like:

ip__resolve_ams(machine, thr, &mi->daddr, sample->addr);
ip__resolve_data(machine, thr, cpumode, &mi->iaddr, sample->ip);

we have correct cpumode for sample->ip, but I think it's the
PEBS->dla (sample->addr) where we need to guess.. right?

that makes me think that we could probably use ip__resolve_data
for both.. hummm.. but we could access data cross the user/kernel
boundary, so cpumode would be different for ip and accessed data

thanks,
jirka
--
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/