Ping.
> On 5 Jun 2017, at 10:11, Elo, Matias (Nokia - FI/Espoo) > <[email protected]> wrote: > > >> On 2 Jun 2017, at 16:48, Maxim Uvarov <[email protected]> wrote: >> >> On 06/02/17 12:44, Elo, Matias (Nokia - FI/Espoo) wrote: >>>>> >>>>> /** >>>>> + * System huge page sizes in bytes >>>>> + * >>>>> + * Returns the number of huge page sizes supported by the system. >>>>> Outputs up to >>>>> + * 'num' sizes when the 'size' array pointer is not NULL. If return >>>>> value is >>>>> + * larger than 'num', there are more supported sizes than the function >>>>> was >>>>> + * allowed to output. If return value (N) is less than 'num', only sizes >>>>> + * [0 ... N-1] have been written. Returned values are ordered from >>>>> smallest to >>>>> + * largest. >>>>> + * >>>>> + * @param[out] size Points to an array of huge page sizes for output >>>>> + * @param num Maximum number of huge page sizes to output >>>>> + * >>>>> + * @return Number of supported huge page sizes >>>>> + * @retval 0 on no huge pages >>>>> + */ >>>>> +unsigned odp_sys_huge_page_size_all(uint64_t size[], unsigned num); >>>>> + >>>> >>>> I think it has to be int. -1 on error, 0 - no hp, > 0 pages. >>>> For linux it might be similar to getpagesizes() >>>> https://linux.die.net/man/3/getpagesizes >>>> """ >>>> if pagesizes is NULL and n_elem is 0, then the number of pages the >>>> system supports is returned. Otherwise, pagesizes is filled with at most >>>> n_elem page sizes. >>>> """ >>>> >>> >>> getpagesizes() returns -1 in a case of invalid function arguments. >>> odp_sys_huge_page_size_all() is documented so that the application cannot >>> pass invalid arguments. So an internal error would be the only possibility. >>> I don't see this to be likely as the function is only reading system info. >>> >>> Adding -1 return value would also increase application complexity as the >>> error return value would require special handling from application. >>> >> >> We have to be consistent with all odp api functions. We do not have >> unsigned function, they are int. > > We do have odp_pktio_max_index(), which returns unsigned, and anyway this > shouldn't be a reason not to use otherwise valid return value. Regarding > consistency, not returning -1 follows the same return value style as the rest > of the functions in system_info.h (odp_sys_huge_page_size(), > odp_sys_page_size(), odp_sys_cache_line_size()). > >> This function is not fast path so >> additional check is ok. And -1 can be returned on permission error to >> assess /proc or /sys files for example or any other internal failure. > > From application point of view the outcome is still the same (no huge pages) > and returning -1 would make this function inconsistent with the other > functions in this module as noted above. > > -Matias > >
