Re: [PATCH net-next 1/3] perf: generalize perf_callchain

[Peter Zijlstra]

On Wed, Feb 17, 2016 at 07:58:57PM -0800, Alexei Starovoitov wrote:
> +static inline int perf_callchain_store(struct perf_callchain_entry *entry, 
> u64 ip)
>  {
> +     if (entry->nr < PERF_MAX_STACK_DEPTH) {
>               entry->ip[entry->nr++] = ip;
> +             return 0;
> +     } else {
> +             return -1; /* no more room, stop walking the stack */
> +     }
>  }

Why 0 and -1 ?

What's wrong with something like:

static inline bool perf_callchain_store(struct perf_callchain_entry *entry, u64 
ip)
{
        if (entry->nr < PERF_MAX_STACK_DEPTH) {
                entry->ip[entry->nr++] = ip;
                return true;
        }
        return false;
}