linux/drivers/infiniband
Md Haris Iqbal 0cdfb3b207 RDMA/rtrs-srv: Replace atomic_t with percpu_ref for ids_inflight
ids_inflight is used to track the inflight IOs. But the use of atomic_t
variable can cause performance drops and can also become a performance
bottleneck.

This commit replaces the use of atomic_t with a percpu_ref structure. The
advantage it offers is, it doesn't check if the reference has fallen to 0,
until the user explicitly signals it to; and that is done by the
percpu_ref_kill() function call. After that, the percpu_ref structure
behaves like an atomic_t and for every put call, checks whether the
reference has fallen to 0 or not.

rtrs_srv_stats_rdma_to_str shows the count of ids_inflight as 0
for user-mode tools not to be confused.

Fixes: 9cb8374804 ("RDMA/rtrs: server: main functionality")
Link: https://lore.kernel.org/r/20210528113018.52290-14-jinpu.wang@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2021-05-28 20:52:58 -03:00
..
core RDMA/core: Use the DEVICE_ATTR_RO macro 2021-05-28 20:39:51 -03:00
hw RDMA/hns: Refactor capability configuration flow of VF 2021-05-28 20:25:37 -03:00
sw RDMA/rxe: Remove unused parameter udata 2021-05-20 11:52:17 -03:00
ulp RDMA/rtrs-srv: Replace atomic_t with percpu_ref for ids_inflight 2021-05-28 20:52:58 -03:00
Kconfig RDMA/umem: Support importing dma-buf as user memory region 2021-01-20 16:07:52 -04:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00