When we try to evenly divide transport buffers between poll grouos,
e.g. when we run spdk_tgt on 8 cores, set num_shared_buffers=32768
and pg buf_cache_size=4096, the last pg can't retrieve enough
buffers to fill cache. In my case if only got 4040 buffers out of
4096. Missing 56 buffers were cached by previous poll groups.
That occurred due to mempool has per lcore cache of 512 elements
and when it becomes empty, the cache is refilled. It seems that
each poll group cached extra 8 buffers.
The issue doesn't occur when we use mempool_get_bulk.
Change-Id: I866d58aa03986a3cffe27402b12f9a2519097f83
Signed-off-by: Alexey Marchuk <alexeymar@mellanox.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/3881
Community-CI: Broadcom CI
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
903fdb752b