Re: [PATCH v3 3/3] mempool: allow for user-owned mempool caches

[Lazaros Koromilas <l@nofutznetworks.com>]

On Fri, Jun 17, 2016 at 11:37 AM, Olivier Matz <olivier.matz@6wind.com> wrote:
>
>
> On 06/16/2016 01:02 PM, Lazaros Koromilas wrote:
>> The mempool cache is only available to EAL threads as a per-lcore
>> resource. Change this so that the user can create and provide their own
>> cache on mempool get and put operations. This works with non-EAL threads
>> too. This commit introduces the new API calls:
>>
>>     rte_mempool_cache_create(size, socket_id)
>>     rte_mempool_cache_free(cache)
>>     rte_mempool_cache_flush(cache, mp)
>>     rte_mempool_default_cache(mp, lcore_id)
>
> These new functions should be added in the .map file, else it will
> break the compilation in with shared_lib=y.

Oops, thanks!

>> Changes the API calls:
>>
>>     rte_mempool_generic_put(mp, obj_table, n, cache, flags)
>>     rte_mempool_generic_get(mp, obj_table, n, cache, flags)
>>
>> The cache-oblivious API calls use the per-lcore default local cache.
>>
>> Signed-off-by: Lazaros Koromilas <l@nofutznetworks.com>
>> ---
>>  app/test/test_mempool.c          |  94 ++++++++++++++++------
>>  app/test/test_mempool_perf.c     |  70 ++++++++++++++---
>>  lib/librte_mempool/rte_mempool.c |  66 +++++++++++++++-
>>  lib/librte_mempool/rte_mempool.h | 163 ++++++++++++++++++++++++++++-----------
>>  4 files changed, 310 insertions(+), 83 deletions(-)
>>
>> diff --git a/app/test/test_mempool.c b/app/test/test_mempool.c
>> index 10d706f..723cd39 100644
>> --- a/app/test/test_mempool.c
>> +++ b/app/test/test_mempool.c
>> @@ -79,6 +79,9 @@
>>               printf("test failed at %s():%d\n", __func__, __LINE__); \
>>               return -1;                                              \
>>       } while (0)
>> +#define LOG_ERR() do {                                                       \
>> +             printf("test failed at %s():%d\n", __func__, __LINE__); \
>> +     } while (0)
>>
>
> I see that the usage of this macro is always like this:
>
>         LOG_ERR();
>         ret = -1;
>         goto out;
>
> What do you think of having:
>
> #define LOG_ERR() do {                                          \
>         printf("test failed at %s():%d\n", __func__, __LINE__); \
>         } while (0)
> #define RET_ERR() do { LOG_ERR(); return -1; } while (0)
> #define GOTO_ERR() do { LOG_ERR(); ret = -1; goto out; } while (0)
>
> Then use GOTO_ERR() when appropriate. It would also factorize
> the printf.

The downside of GOTO_ERR() is that it assumes a variable and a label
name. And you may need to have multiple labels 'out0', 'out1', etc for
the error path. How about:

#define GOTO_ERR(ret, out) do { LOG_ERR(); ret = -1; goto out; } while (0)

Lazaros.