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authorChuck Lever <chuck.lever@oracle.com>2020-12-29 23:55:17 +0300
committerChuck Lever <chuck.lever@oracle.com>2021-01-25 17:36:28 +0300
commit22df5a22462e836ccb30634c3a52602091179a73 (patch)
tree26ac5784c1285499b0a1598cba5a3eab27658ebe /net
parentdf971cd853c05778ae1175e8aeb80a04bb9d4be5 (diff)
downloadlinux-22df5a22462e836ccb30634c3a52602091179a73.tar.xz
svcrdma: Convert rdma_stat_sq_starve to a per-CPU counter
Avoid the overhead of a memory bus lock cycle for counting a value that is hardly every used. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'net')
-rw-r--r--net/sunrpc/xprtrdma/svc_rdma.c13
-rw-r--r--net/sunrpc/xprtrdma/svc_rdma_rw.c1
-rw-r--r--net/sunrpc/xprtrdma/svc_rdma_sendto.c2
3 files changed, 11 insertions, 5 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma.c b/net/sunrpc/xprtrdma/svc_rdma.c
index 3e5e622bad81..ee768d4c3c90 100644
--- a/net/sunrpc/xprtrdma/svc_rdma.c
+++ b/net/sunrpc/xprtrdma/svc_rdma.c
@@ -66,7 +66,7 @@ static unsigned int max_max_inline = RPCRDMA_MAX_INLINE_THRESH;
struct percpu_counter svcrdma_stat_recv;
atomic_t rdma_stat_read;
atomic_t rdma_stat_write;
-atomic_t rdma_stat_sq_starve;
+struct percpu_counter svcrdma_stat_sq_starve;
atomic_t rdma_stat_rq_starve;
atomic_t rdma_stat_rq_poll;
atomic_t rdma_stat_rq_prod;
@@ -199,10 +199,10 @@ static struct ctl_table svcrdma_parm_table[] = {
},
{
.procname = "rdma_stat_sq_starve",
- .data = &rdma_stat_sq_starve,
- .maxlen = sizeof(atomic_t),
+ .data = &svcrdma_stat_sq_starve,
+ .maxlen = SVCRDMA_COUNTER_BUFSIZ,
.mode = 0644,
- .proc_handler = read_reset_stat,
+ .proc_handler = svcrdma_counter_handler,
},
{
.procname = "rdma_stat_rq_starve",
@@ -267,6 +267,7 @@ static void svc_rdma_proc_cleanup(void)
unregister_sysctl_table(svcrdma_table_header);
svcrdma_table_header = NULL;
+ percpu_counter_destroy(&svcrdma_stat_sq_starve);
percpu_counter_destroy(&svcrdma_stat_recv);
}
@@ -280,11 +281,15 @@ static int svc_rdma_proc_init(void)
rc = percpu_counter_init(&svcrdma_stat_recv, 0, GFP_KERNEL);
if (rc)
goto out_err;
+ rc = percpu_counter_init(&svcrdma_stat_sq_starve, 0, GFP_KERNEL);
+ if (rc)
+ goto out_err;
svcrdma_table_header = register_sysctl_table(svcrdma_root_table);
return 0;
out_err:
+ percpu_counter_destroy(&svcrdma_stat_recv);
return rc;
}
diff --git a/net/sunrpc/xprtrdma/svc_rdma_rw.c b/net/sunrpc/xprtrdma/svc_rdma_rw.c
index 0b63e1321d74..d7d98b2df00b 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_rw.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c
@@ -364,6 +364,7 @@ static int svc_rdma_post_chunk_ctxt(struct svc_rdma_chunk_ctxt *cc)
return 0;
}
+ percpu_counter_inc(&svcrdma_stat_sq_starve);
trace_svcrdma_sq_full(rdma);
atomic_add(cc->cc_sqecount, &rdma->sc_sq_avail);
wait_event(rdma->sc_send_wait,
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index 68af79d4f04f..52c759a8543e 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -317,7 +317,7 @@ int svc_rdma_send(struct svcxprt_rdma *rdma, struct svc_rdma_send_ctxt *ctxt)
/* If the SQ is full, wait until an SQ entry is available */
while (1) {
if ((atomic_dec_return(&rdma->sc_sq_avail) < 0)) {
- atomic_inc(&rdma_stat_sq_starve);
+ percpu_counter_inc(&svcrdma_stat_sq_starve);
trace_svcrdma_sq_full(rdma);
atomic_inc(&rdma->sc_sq_avail);
wait_event(rdma->sc_send_wait,