From 04fb94c99160ae1c6dea02624fefd47eb48da810 Mon Sep 17 00:00:00 2001 From: Mohit Agrawal Date: Mon, 14 Aug 2017 10:15:45 +0530 Subject: rpc: Eliminate conn->lock contention by using more granular locks rpc_clnt_submit() acquires conn->lock before call to rpc_transport_submit_request() and subsequent queuing of frame into saved_frames list. However, as part of handling RPC_TRANSPORT_MSG_RECEIVED and RPC_TRANSPORT_MSG_SENT notifications in rpc_clnt_notify(), conn->lock is again used to atomically update conn->last_received and conn->last_sent event timestamps. So when conn->lock is acquired as part of submitting a request, a parallel POLLIN notification gets blocked at rpc layer until the request submission completes and the lock is released. To get around this, this patch call clock_gettime (instead to call gettimeofday) to update event timestamps in conn->last_received and conn->last_sent and to call clock_gettime don't need to call mutex_lock because it (clock_gettime) is thread safe call. Note: Run fio on vm after apply the patch, iops is improved after apply the patch. Change-Id: I347b5031d61c426b276bc5e07136a7172645d763 BUG: 1467614 Signed-off-by: Krutika Dhananjay --- rpc/rpc-lib/src/rpc-clnt.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) (limited to 'rpc/rpc-lib/src/rpc-clnt.c') diff --git a/rpc/rpc-lib/src/rpc-clnt.c b/rpc/rpc-lib/src/rpc-clnt.c index adb8e3d4a60..cb59408dcf6 100644 --- a/rpc/rpc-lib/src/rpc-clnt.c +++ b/rpc/rpc-lib/src/rpc-clnt.c @@ -965,11 +965,7 @@ rpc_clnt_notify (rpc_transport_t *trans, void *mydata, case RPC_TRANSPORT_MSG_RECEIVED: { - pthread_mutex_lock (&conn->lock); - { - gettimeofday (&conn->last_received, NULL); - } - pthread_mutex_unlock (&conn->lock); + clock_gettime (CLOCK_REALTIME, &conn->last_received); pollin = data; if (pollin->is_reply) @@ -984,11 +980,7 @@ rpc_clnt_notify (rpc_transport_t *trans, void *mydata, case RPC_TRANSPORT_MSG_SENT: { - pthread_mutex_lock (&conn->lock); - { - gettimeofday (&conn->last_sent, NULL); - } - pthread_mutex_unlock (&conn->lock); + clock_gettime (CLOCK_REALTIME, &conn->last_sent); ret = 0; break; -- cgit