Re: [PATCH] lib/mempool : rte_mempool_avail_count, fixing return bigger than mempool size

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue, 16 May 2023 13:41:46 +0000
Yasin CANER <yasinncaner@gmail.com> wrote:

> From: Yasin CANER <yasin.caner@ulakhaberlesme.com.tr>
> 
> after a while working rte_mempool_avail_count function returns bigger
> than mempool size that cause miscalculation rte_mempool_in_use_count.
> 
> it helps to avoid miscalculation rte_mempool_in_use_count.
> 
> Bugzilla ID: 1229
> 
> Signed-off-by: Yasin CANER <yasin.caner@ulakhaberlesme.com.tr>

An alternative that avoids some code duplication.

diff --git a/lib/mempool/rte_mempool.c b/lib/mempool/rte_mempool.c
index cf5dea2304a7..2406b112e7b0 100644
--- a/lib/mempool/rte_mempool.c
+++ b/lib/mempool/rte_mempool.c
@@ -1010,7 +1010,7 @@ rte_mempool_avail_count(const struct rte_mempool *mp)
        count = rte_mempool_ops_get_count(mp);
 
        if (mp->cache_size == 0)
-               return count;
+               goto exit;
 
        for (lcore_id = 0; lcore_id < RTE_MAX_LCORE; lcore_id++)
                count += mp->local_cache[lcore_id].len;
@@ -1019,6 +1019,7 @@ rte_mempool_avail_count(const struct rte_mempool *mp)
         * due to race condition (access to len is not locked), the
         * total can be greater than size... so fix the result
         */
+exit:
        if (count > mp->size)
                return mp->size;
        return count;