diff options
| author | Md Haris Iqbal <haris.iqbal@cloud.ionos.com> | 2021-05-28 13:30:11 +0200 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2021-05-29 01:52:58 +0200 |
| commit | 0cdfb3b20797804ae835d7a325b08d8523794089 (patch) | |
| tree | ccfdc325591867027803365ebff65dd440d8ec91 /drivers/infiniband/ulp/rtrs/rtrs-srv-stats.c | |
| parent | RDMA/rtrs-clt: Check state of the rtrs_clt_sess before reading its stats (diff) | |
| download | linux-0cdfb3b20797804ae835d7a325b08d8523794089.tar.xz linux-0cdfb3b20797804ae835d7a325b08d8523794089.zip | |
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: 9cb837480424e ("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>
Diffstat (limited to 'drivers/infiniband/ulp/rtrs/rtrs-srv-stats.c')
| -rw-r--r-- | drivers/infiniband/ulp/rtrs/rtrs-srv-stats.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv-stats.c b/drivers/infiniband/ulp/rtrs/rtrs-srv-stats.c index e102b1368d0c..520c24773229 100644 --- a/drivers/infiniband/ulp/rtrs/rtrs-srv-stats.c +++ b/drivers/infiniband/ulp/rtrs/rtrs-srv-stats.c @@ -27,12 +27,10 @@ ssize_t rtrs_srv_stats_rdma_to_str(struct rtrs_srv_stats *stats, char *page, size_t len) { struct rtrs_srv_stats_rdma_stats *r = &stats->rdma_stats; - struct rtrs_srv_sess *sess = stats->sess; - return scnprintf(page, len, "%lld %lld %lld %lld %u\n", - (s64)atomic64_read(&r->dir[READ].cnt), - (s64)atomic64_read(&r->dir[READ].size_total), - (s64)atomic64_read(&r->dir[WRITE].cnt), - (s64)atomic64_read(&r->dir[WRITE].size_total), - atomic_read(&sess->ids_inflight)); + return scnprintf(page, len, "%lld %lld %lld %lldn %u\n", + (s64)atomic64_read(&r->dir[READ].cnt), + (s64)atomic64_read(&r->dir[READ].size_total), + (s64)atomic64_read(&r->dir[WRITE].cnt), + (s64)atomic64_read(&r->dir[WRITE].size_total), 0); } |