Return-Path: Received: from mail-yk0-f182.google.com ([209.85.160.182]:34962 "EHLO mail-yk0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752153AbbJEXDh (ORCPT ); Mon, 5 Oct 2015 19:03:37 -0400 Received: by ykdz138 with SMTP id z138so186606968ykd.2 for ; Mon, 05 Oct 2015 16:03:36 -0700 (PDT) From: Trond Myklebust To: linux-nfs@vger.kernel.org Subject: [RFC PATCH 3/3] SUNRPC: Allow TCP to replace the bh-safe lock in receive path Date: Mon, 5 Oct 2015 19:03:31 -0400 Message-Id: <1444086211-4811-3-git-send-email-trond.myklebust@primarydata.com> In-Reply-To: <1444086211-4811-2-git-send-email-trond.myklebust@primarydata.com> References: <1444086211-4811-1-git-send-email-trond.myklebust@primarydata.com> <1444086211-4811-2-git-send-email-trond.myklebust@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: This patch attempts to eke out a couple more iops by allowing the TCP code to replace bh-safe spinlock with an ordinary one while receiving data. We still need to use the bh-safe spinlock when completing. Signed-off-by: Trond Myklebust --- net/sunrpc/xprt.c | 4 ++++ net/sunrpc/xprtsock.c | 17 ++++++++++------- 2 files changed, 14 insertions(+), 7 deletions(-) diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 2e98f4a243e5..e604bb680bcf 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -951,6 +951,7 @@ void xprt_transmit(struct rpc_task *task) /* * Add to the list only if we're expecting a reply */ + spin_lock(&xprt->reserve_lock); spin_lock_bh(&xprt->transport_lock); /* Update the softirq receive buffer */ memcpy(&req->rq_private_buf, &req->rq_rcv_buf, @@ -958,6 +959,7 @@ void xprt_transmit(struct rpc_task *task) /* Add request to the receive list */ list_add_tail(&req->rq_list, &xprt->recv); spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->reserve_lock); xprt_reset_majortimeo(req); /* Turn off autodisconnect */ del_singleshot_timer_sync(&xprt->timer); @@ -1278,6 +1280,7 @@ void xprt_release(struct rpc_task *task) task->tk_ops->rpc_count_stats(task, task->tk_calldata); else if (task->tk_client) rpc_count_iostats(task, task->tk_client->cl_metrics); + spin_lock(&xprt->reserve_lock); spin_lock_bh(&xprt->transport_lock); xprt->ops->release_xprt(xprt, task); if (xprt->ops->release_request) @@ -1289,6 +1292,7 @@ void xprt_release(struct rpc_task *task) mod_timer(&xprt->timer, xprt->last_used + xprt->idle_timeout); spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->reserve_lock); if (req->rq_buffer) xprt->ops->buf_free(req->rq_buffer); xprt_inject_disconnect(xprt); diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 58dc90ccebb6..063d2eb20d8e 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1246,21 +1246,24 @@ static inline int xs_tcp_read_reply(struct rpc_xprt *xprt, dprintk("RPC: read reply XID %08x\n", ntohl(transport->tcp_xid)); /* Find and lock the request corresponding to this xid */ - spin_lock_bh(&xprt->transport_lock); + spin_lock(&xprt->reserve_lock); req = xprt_lookup_rqst(xprt, transport->tcp_xid); if (!req) { dprintk("RPC: XID %08x request not found!\n", ntohl(transport->tcp_xid)); - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->reserve_lock); return -1; } xs_tcp_read_common(xprt, desc, req); - if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) + if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) { + spin_lock_bh(&xprt->transport_lock); xprt_complete_rqst(req->rq_task, transport->tcp_copied); + spin_unlock_bh(&xprt->transport_lock); + } - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->reserve_lock); return 0; } @@ -1280,10 +1283,10 @@ static int xs_tcp_read_callback(struct rpc_xprt *xprt, struct rpc_rqst *req; /* Look up and lock the request corresponding to the given XID */ - spin_lock_bh(&xprt->transport_lock); + spin_lock(&xprt->reserve_lock); req = xprt_lookup_bc_request(xprt, transport->tcp_xid); if (req == NULL) { - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->reserve_lock); printk(KERN_WARNING "Callback slot table overflowed\n"); xprt_force_disconnect(xprt); return -1; @@ -1294,7 +1297,7 @@ static int xs_tcp_read_callback(struct rpc_xprt *xprt, if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) xprt_complete_bc_request(req, transport->tcp_copied); - spin_unlock_bh(&xprt->transport_lock); + spin_unlock(&xprt->reserve_lock); return 0; } -- 2.4.3