Messages in this thread | | | Date | Mon, 17 Nov 2014 16:55:53 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH V3 3/3] perf tools: Construct LBR call chain |
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On Fri, Nov 14, 2014 at 08:44:12AM -0500, kan.liang@intel.com wrote:
SNIP
> + if (lbr) { > + for (i = 0; i < chain_nr; i++) { > + if (chain->ips[i] == PERF_CONTEXT_USER) > + break; > + } > + > + /* LBR only affects the user callchain */ > + if (i != chain_nr) { > + struct branch_stack *lbr_stack = sample->branch_stack; > + int lbr_nr = lbr_stack->nr; > + /* > + * LBR callstack can only get user call chain. > + * The mix_chain_nr is kernel call chain > + * number plus LBR user call chain number. > + * i is kernel call chain number, > + * 1 is PERF_CONTEXT_USER, > + * lbr_nr + 1 is the user call chain number. > + * For details, please refer to the comments > + * in callchain__printf > + */ > + int mix_chain_nr = i + 1 + lbr_nr + 1; > + > + if (mix_chain_nr > PERF_MAX_STACK_DEPTH) { > + pr_warning("corrupted callchain. skipping...\n"); > + return 0; > + } > + > + for (j = 0; j < mix_chain_nr; j++) { > + if (callchain_param.order == ORDER_CALLEE) { > + if (j < i + 1) > + ip = chain->ips[j]; > + else if (j > i + 1) > + ip = lbr_stack->entries[j - i - 2].from; > + else > + ip = lbr_stack->entries[0].to; > + } else { > + if (j < lbr_nr) > + ip = lbr_stack->entries[lbr_nr - j - 1].from; > + else if (j > lbr_nr) > + ip = chain->ips[i + 1 - (j - lbr_nr)]; > + else > + ip = lbr_stack->entries[0].to; > + } > + > + err = add_callchain_ip(thread, parent, root_al, > + cpumode, ip); > + if (err) > + goto exit; > + } > + return 0; > + } > + }
also could you please move whole block above into separated function? Andi has another change for this function and it's becoming really big.
other then that I think it's ok IMO and I could ack next version
thanks, jirka
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