[PATCH v2 for-next 3/5] RDMA/rtrs-srv: Use per-cpu variables for rdma stats

[Md Haris Iqbal <haris.iqbal@ionos.com>]

From: Santosh Kumar Pradhan <santosh.pradhan@ionos.com>

Convert server stat counters from atomic to per-cpu variables.

Signed-off-by: Santosh Kumar Pradhan <santosh.pradhan@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
---
v1 -> v2: No change

 drivers/infiniband/ulp/rtrs/rtrs-srv-stats.c | 32 +++++++++++++++-----
 drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c |  2 ++
 drivers/infiniband/ulp/rtrs/rtrs-srv.c       |  9 +++++-
 drivers/infiniband/ulp/rtrs/rtrs-srv.h       | 15 ++++-----
 4 files changed, 42 insertions(+), 16 deletions(-)

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv-stats.c b/drivers/infiniband/ulp/rtrs/rtrs-srv-stats.c
index 44b1c1652131..2aff1213a19d 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-srv-stats.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv-stats.c
@@ -14,9 +14,14 @@
 int rtrs_srv_reset_rdma_stats(struct rtrs_srv_stats *stats, bool enable)
 {
 	if (enable) {
-		struct rtrs_srv_stats_rdma_stats *r = &stats->rdma_stats;
+		int cpu;
+		struct rtrs_srv_stats_rdma_stats *r;
+
+		for_each_possible_cpu(cpu) {
+			r = per_cpu_ptr(stats->rdma_stats, cpu);
+			memset(r, 0, sizeof(*r));
+		}
 
-		memset(r, 0, sizeof(*r));
 		return 0;
 	}
 
@@ -25,11 +30,22 @@ int rtrs_srv_reset_rdma_stats(struct rtrs_srv_stats *stats, bool enable)
 
 ssize_t rtrs_srv_stats_rdma_to_str(struct rtrs_srv_stats *stats, char *page)
 {
-	struct rtrs_srv_stats_rdma_stats *r = &stats->rdma_stats;
+	int cpu;
+	struct rtrs_srv_stats_rdma_stats sum;
+	struct rtrs_srv_stats_rdma_stats *r;
+
+	memset(&sum, 0, sizeof(sum));
+
+	for_each_possible_cpu(cpu) {
+		r = per_cpu_ptr(stats->rdma_stats, cpu);
+
+		sum.dir[READ].cnt	  += r->dir[READ].cnt;
+		sum.dir[READ].size_total  += r->dir[READ].size_total;
+		sum.dir[WRITE].cnt	  += r->dir[WRITE].cnt;
+		sum.dir[WRITE].size_total += r->dir[WRITE].size_total;
+	}
 
-	return sysfs_emit(page, "%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);
+	return sysfs_emit(page, "%llu %llu %llu %llu\n",
+			  sum.dir[READ].cnt, sum.dir[READ].size_total,
+			  sum.dir[WRITE].cnt, sum.dir[WRITE].size_total);
 }
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c b/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c
index b94ae12c2795..2a3c9ac64a42 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c
@@ -220,6 +220,8 @@ static void rtrs_srv_path_stats_release(struct kobject *kobj)
 
 	stats = container_of(kobj, struct rtrs_srv_stats, kobj_stats);
 
+	free_percpu(stats->rdma_stats);
+
 	kfree(stats);
 }
 
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.c b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
index 24024bce2566..8278d3600a36 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
@@ -1513,6 +1513,7 @@ static void free_path(struct rtrs_srv_path *srv_path)
 		kobject_del(&srv_path->kobj);
 		kobject_put(&srv_path->kobj);
 	} else {
+		free_percpu(srv_path->stats->rdma_stats);
 		kfree(srv_path->stats);
 		kfree(srv_path);
 	}
@@ -1755,13 +1756,17 @@ static struct rtrs_srv_path *__alloc_path(struct rtrs_srv_sess *srv,
 	if (!srv_path->stats)
 		goto err_free_sess;
 
+	srv_path->stats->rdma_stats = alloc_percpu(struct rtrs_srv_stats_rdma_stats);
+	if (!srv_path->stats->rdma_stats)
+		goto err_free_stats;
+
 	srv_path->stats->srv_path = srv_path;
 
 	srv_path->dma_addr = kcalloc(srv->queue_depth,
 				     sizeof(*srv_path->dma_addr),
 				     GFP_KERNEL);
 	if (!srv_path->dma_addr)
-		goto err_free_stats;
+		goto err_free_percpu;
 
 	srv_path->s.con = kcalloc(con_num, sizeof(*srv_path->s.con),
 				  GFP_KERNEL);
@@ -1813,6 +1818,8 @@ static struct rtrs_srv_path *__alloc_path(struct rtrs_srv_sess *srv,
 	kfree(srv_path->s.con);
 err_free_dma_addr:
 	kfree(srv_path->dma_addr);
+err_free_percpu:
+	free_percpu(srv_path->stats->rdma_stats);
 err_free_stats:
 	kfree(srv_path->stats);
 err_free_sess:
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.h b/drivers/infiniband/ulp/rtrs/rtrs-srv.h
index 6292e87f6afd..186a63c217df 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-srv.h
+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.h
@@ -12,6 +12,7 @@
 
 #include <linux/device.h>
 #include <linux/refcount.h>
+#include <linux/percpu.h>
 #include "rtrs-pri.h"
 
 /*
@@ -29,15 +30,15 @@ enum rtrs_srv_state {
  */
 struct rtrs_srv_stats_rdma_stats {
 	struct {
-		atomic64_t	cnt;
-		atomic64_t	size_total;
+		u64 cnt;
+		u64 size_total;
 	} dir[2];
 };
 
 struct rtrs_srv_stats {
-	struct kobject				kobj_stats;
-	struct rtrs_srv_stats_rdma_stats	rdma_stats;
-	struct rtrs_srv_path			*srv_path;
+	struct kobject					kobj_stats;
+	struct rtrs_srv_stats_rdma_stats __percpu	*rdma_stats;
+	struct rtrs_srv_path				*srv_path;
 };
 
 struct rtrs_srv_con {
@@ -130,8 +131,8 @@ void close_path(struct rtrs_srv_path *srv_path);
 static inline void rtrs_srv_update_rdma_stats(struct rtrs_srv_stats *s,
 					      size_t size, int d)
 {
-	atomic64_inc(&s->rdma_stats.dir[d].cnt);
-	atomic64_add(size, &s->rdma_stats.dir[d].size_total);
+	this_cpu_inc(s->rdma_stats->dir[d].cnt);
+	this_cpu_add(s->rdma_stats->dir[d].size_total, size);
 }
 
 /* functions which are implemented in rtrs-srv-stats.c */
-- 
2.25.1