Re: [RFC PATCH v3 30/37] perf bpf: Add bpf-loader and open ELF object files

Wangnan (F)
2015-05-25T11:47:48Z

On 2015/5/23 1:24, Jiri Olsa wrote:
> On Sun, May 17, 2015 at 10:56:55AM +0000, Wang Nan wrote:
>
> SNIP
>
>> +#define DEFINE_PRINT_FN(name, level) \
>> +static int libbpf_##name(const char *fmt, ...) \
>> +{ \
>> + va_list args; \
>> + int ret; \
>> + \
>> + va_start(args, fmt); \
>> + ret = veprintf(level, verbose, pr_fmt(fmt), args);\
>> + va_end(args); \
>> + return ret; \
>> +}
>> +
>> +DEFINE_PRINT_FN(warning, 0)
>> +DEFINE_PRINT_FN(info, 0)
>> +DEFINE_PRINT_FN(debug, 1)
>> +
>> +static bool libbpf_inited = false;
>> +
>> +#define MAX_OBJECTS 128
>> +
>> +struct {
>> + struct bpf_object *objects[MAX_OBJECTS];
>> + size_t nr_objects;
>> +} params;
> apart from that we dont like this kind of static stuff, this seems like
> nice case for having simple handler like 'struct bpf_objects' carrying
> the above data.. what do I miss?

I want to avoid fragmented memory allocation for storing bpf_object
pointers.
Storing them together into an array can make code simpler. I think I can
made
something like 'struct bpf_object *bpf_next_object(obj)' in libbpf so we can
iterate over each loaded bpf objects, then this array and nr_objects can be
hidden.

> also params should actually be static right?
>
> jirka