Re: [PATCH] Add inverted call graph report support to perf tool

From: Arun Sharma
Date: Thu Mar 17 2011 - 13:53:50 EST


On Mon, Mar 07, 2011 at 09:43:27PM +0800, Sam Liao wrote:
> +
> + /* reverse call chain data */
> + if (reverse_call && symbol_conf.use_callchain && sample->callchain) {

You probably want to check for nr > 1 here, as in:

/* reverse call chain data */
- if (reverse_call && symbol_conf.use_callchain && sample->callchain) {
+ if (reverse_call && symbol_conf.use_callchain && sample->callchain
+ && (sample->callchain->nr > 1)) {
struct ip_callchain *chain;
int i, j;
u64 tmp_ip;

Otherwise, if you get a callchain with ->nr == 0, the loop with (nr - 2) will
go on for a long time.

-Arun
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