From patchwork Wed Feb 3 16:23:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12064719 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1731C433E6 for ; Wed, 3 Feb 2021 16:24:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 95D5264F7E for ; Wed, 3 Feb 2021 16:24:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233358AbhBCQYi (ORCPT ); Wed, 3 Feb 2021 11:24:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:40154 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229663AbhBCQYg (ORCPT ); Wed, 3 Feb 2021 11:24:36 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4DD6E64F7E; Wed, 3 Feb 2021 16:23:55 +0000 (UTC) Subject: [PATCH v2 1/6] xprtrdma: Remove FMR support in rpcrdma_convert_iovs() From: Chuck Lever To: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org Date: Wed, 03 Feb 2021 11:23:54 -0500 Message-ID: <161236943446.1030487.4542967452464402073.stgit@manet.1015granger.net> In-Reply-To: <161236925476.1030487.10407536259816633879.stgit@manet.1015granger.net> References: <161236925476.1030487.10407536259816633879.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Support for FMR was removed by commit ba69cd122ece ("xprtrdma: Remove support for FMR memory registration") [Dec 2018]. That means the buffer-splitting behavior of rpcrdma_convert_kvec(), added by commit 821c791a0bde ("xprtrdma: Segment head and tail XDR buffers on page boundaries") [Mar 2016], is no longer necessary. FRWR memory registration handles this case with aplomb. Signed-off-by: Chuck Lever --- net/sunrpc/xprtrdma/rpc_rdma.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index 8f5d0cb68360..832765f3ebba 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -204,9 +204,7 @@ rpcrdma_alloc_sparse_pages(struct xdr_buf *buf) return 0; } -/* Split @vec on page boundaries into SGEs. FMR registers pages, not - * a byte range. Other modes coalesce these SGEs into a single MR - * when they can. +/* Convert @vec to a single SGL element. * * Returns pointer to next available SGE, and bumps the total number * of SGEs consumed. @@ -215,21 +213,12 @@ static struct rpcrdma_mr_seg * rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg, unsigned int *n) { - u32 remaining, page_offset; - char *base; - - base = vec->iov_base; - page_offset = offset_in_page(base); - remaining = vec->iov_len; - while (remaining) { + if (vec->iov_len) { seg->mr_page = NULL; - seg->mr_offset = base; - seg->mr_len = min_t(u32, PAGE_SIZE - page_offset, remaining); - remaining -= seg->mr_len; - base += seg->mr_len; + seg->mr_offset = vec->iov_base; + seg->mr_len = vec->iov_len; ++seg; ++(*n); - page_offset = 0; } return seg; } From patchwork Wed Feb 3 16:24:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12064717 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28FC4C433E9 for ; Wed, 3 Feb 2021 16:24:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8BA764F7C for ; Wed, 3 Feb 2021 16:24:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233436AbhBCQYo (ORCPT ); Wed, 3 Feb 2021 11:24:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:40172 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229663AbhBCQYm (ORCPT ); Wed, 3 Feb 2021 11:24:42 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9149A64F84; Wed, 3 Feb 2021 16:24:01 +0000 (UTC) Subject: [PATCH v2 2/6] xprtrdma: Simplify rpcrdma_convert_kvec() and frwr_map() From: Chuck Lever To: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org Date: Wed, 03 Feb 2021 11:24:00 -0500 Message-ID: <161236944071.1030487.460353530274045763.stgit@manet.1015granger.net> In-Reply-To: <161236925476.1030487.10407536259816633879.stgit@manet.1015granger.net> References: <161236925476.1030487.10407536259816633879.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Clean up. Remove a conditional branch from the SGL set-up loop in frwr_map(): Instead of using either sg_set_page() or sg_set_buf(), initialize the mr_page field properly when rpcrdma_convert_kvec() converts the kvec to an SGL entry. frwr_map() can then invoke sg_set_page() unconditionally. Signed-off-by: Chuck Lever Reviewed-By: Tom Talpey --- net/sunrpc/xprtrdma/frwr_ops.c | 12 ++++-------- net/sunrpc/xprtrdma/rpc_rdma.c | 2 +- net/sunrpc/xprtrdma/xprt_rdma.h | 9 +++++---- 3 files changed, 10 insertions(+), 13 deletions(-) diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c index baca49fe83af..13a50f77dddb 100644 --- a/net/sunrpc/xprtrdma/frwr_ops.c +++ b/net/sunrpc/xprtrdma/frwr_ops.c @@ -306,14 +306,10 @@ struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt, if (nsegs > ep->re_max_fr_depth) nsegs = ep->re_max_fr_depth; for (i = 0; i < nsegs;) { - if (seg->mr_page) - sg_set_page(&mr->mr_sg[i], - seg->mr_page, - seg->mr_len, - offset_in_page(seg->mr_offset)); - else - sg_set_buf(&mr->mr_sg[i], seg->mr_offset, - seg->mr_len); + sg_set_page(&mr->mr_sg[i], + seg->mr_page, + seg->mr_len, + offset_in_page(seg->mr_offset)); ++seg; ++i; diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index 832765f3ebba..529adb6ad4db 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -214,7 +214,7 @@ rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg, unsigned int *n) { if (vec->iov_len) { - seg->mr_page = NULL; + seg->mr_page = virt_to_page(vec->iov_base); seg->mr_offset = vec->iov_base; seg->mr_len = vec->iov_len; ++seg; diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index 94b28657aeeb..02971e183989 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -283,10 +283,11 @@ enum { RPCRDMA_MAX_IOV_SEGS, }; -struct rpcrdma_mr_seg { /* chunk descriptors */ - u32 mr_len; /* length of chunk or segment */ - struct page *mr_page; /* owning page, if any */ - char *mr_offset; /* kva if no page, else offset */ +/* Arguments for DMA mapping and registration */ +struct rpcrdma_mr_seg { + u32 mr_len; /* length of segment */ + struct page *mr_page; /* underlying struct page */ + char *mr_offset; /* IN: page offset, OUT: iova */ }; /* The Send SGE array is provisioned to send a maximum size From patchwork Wed Feb 3 16:24:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12064721 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40D98C433DB for ; Wed, 3 Feb 2021 16:24:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D1CBC64F7E for ; Wed, 3 Feb 2021 16:24:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233500AbhBCQYw (ORCPT ); Wed, 3 Feb 2021 11:24:52 -0500 Received: from mail.kernel.org ([198.145.29.99]:40188 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229663AbhBCQYt (ORCPT ); Wed, 3 Feb 2021 11:24:49 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id D920264F86; Wed, 3 Feb 2021 16:24:07 +0000 (UTC) Subject: [PATCH v2 3/6] xprtrdma: Refactor invocations of offset_in_page() From: Chuck Lever To: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org Date: Wed, 03 Feb 2021 11:24:07 -0500 Message-ID: <161236944700.1030487.6859398915626711523.stgit@manet.1015granger.net> In-Reply-To: <161236925476.1030487.10407536259816633879.stgit@manet.1015granger.net> References: <161236925476.1030487.10407536259816633879.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Clean up so that offset_in_page() is invoked less often in the most common case, which is mapping xdr->pages. Signed-off-by: Chuck Lever Reviewed-By: Tom Talpey --- net/sunrpc/xprtrdma/frwr_ops.c | 8 +++----- net/sunrpc/xprtrdma/rpc_rdma.c | 4 ++-- net/sunrpc/xprtrdma/xprt_rdma.h | 2 +- 3 files changed, 6 insertions(+), 8 deletions(-) diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c index 13a50f77dddb..766a1048a48a 100644 --- a/net/sunrpc/xprtrdma/frwr_ops.c +++ b/net/sunrpc/xprtrdma/frwr_ops.c @@ -306,16 +306,14 @@ struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt, if (nsegs > ep->re_max_fr_depth) nsegs = ep->re_max_fr_depth; for (i = 0; i < nsegs;) { - sg_set_page(&mr->mr_sg[i], - seg->mr_page, - seg->mr_len, - offset_in_page(seg->mr_offset)); + sg_set_page(&mr->mr_sg[i], seg->mr_page, + seg->mr_len, seg->mr_offset); ++seg; ++i; if (ep->re_mrtype == IB_MR_TYPE_SG_GAPS) continue; - if ((i < nsegs && offset_in_page(seg->mr_offset)) || + if ((i < nsegs && seg->mr_offset) || offset_in_page((seg-1)->mr_offset + (seg-1)->mr_len)) break; } diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index 529adb6ad4db..b3e66b8f65ab 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -215,7 +215,7 @@ rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg, { if (vec->iov_len) { seg->mr_page = virt_to_page(vec->iov_base); - seg->mr_offset = vec->iov_base; + seg->mr_offset = offset_in_page(vec->iov_base); seg->mr_len = vec->iov_len; ++seg; ++(*n); @@ -248,7 +248,7 @@ rpcrdma_convert_iovs(struct rpcrdma_xprt *r_xprt, struct xdr_buf *xdrbuf, page_base = offset_in_page(xdrbuf->page_base); while (len) { seg->mr_page = *ppages; - seg->mr_offset = (char *)page_base; + seg->mr_offset = page_base; seg->mr_len = min_t(u32, PAGE_SIZE - page_base, len); len -= seg->mr_len; ++ppages; diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index 02971e183989..ed1c5444fb9d 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -287,7 +287,7 @@ enum { struct rpcrdma_mr_seg { u32 mr_len; /* length of segment */ struct page *mr_page; /* underlying struct page */ - char *mr_offset; /* IN: page offset, OUT: iova */ + u64 mr_offset; /* IN: page offset, OUT: iova */ }; /* The Send SGE array is provisioned to send a maximum size From patchwork Wed Feb 3 16:24:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12064723 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8FC94C433E0 for ; Wed, 3 Feb 2021 16:24:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 54ECC64F7C for ; Wed, 3 Feb 2021 16:24:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233573AbhBCQY5 (ORCPT ); Wed, 3 Feb 2021 11:24:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:40232 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233560AbhBCQY4 (ORCPT ); Wed, 3 Feb 2021 11:24:56 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 285F464F8C; Wed, 3 Feb 2021 16:24:14 +0000 (UTC) Subject: [PATCH v2 4/6] rpcrdma: Fix comments about reverse-direction operation From: Chuck Lever To: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org Date: Wed, 03 Feb 2021 11:24:13 -0500 Message-ID: <161236945329.1030487.13444441650618425746.stgit@manet.1015granger.net> In-Reply-To: <161236925476.1030487.10407536259816633879.stgit@manet.1015granger.net> References: <161236925476.1030487.10407536259816633879.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org During the final stages of publication of RFC 8167, reviewers requested that we use the term "reverse direction" rather than "backwards direction". Update comments to reflect this preference. Signed-off-by: Chuck Lever Reviewed-By: Tom Talpey --- net/sunrpc/xprtrdma/backchannel.c | 4 ++-- net/sunrpc/xprtrdma/rpc_rdma.c | 6 +----- net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 4 ++-- net/sunrpc/xprtrdma/xprt_rdma.h | 6 +++--- 4 files changed, 8 insertions(+), 12 deletions(-) diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c index 946edf2db646..a249837d6a55 100644 --- a/net/sunrpc/xprtrdma/backchannel.c +++ b/net/sunrpc/xprtrdma/backchannel.c @@ -2,7 +2,7 @@ /* * Copyright (c) 2015-2020, Oracle and/or its affiliates. * - * Support for backward direction RPCs on RPC/RDMA. + * Support for reverse-direction RPCs on RPC/RDMA. */ #include @@ -208,7 +208,7 @@ static struct rpc_rqst *rpcrdma_bc_rqst_get(struct rpcrdma_xprt *r_xprt) } /** - * rpcrdma_bc_receive_call - Handle a backward direction call + * rpcrdma_bc_receive_call - Handle a reverse-direction Call * @r_xprt: transport receiving the call * @rep: receive buffer containing the call * diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index b3e66b8f65ab..f0af89a43efd 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -1153,14 +1153,10 @@ rpcrdma_is_bcall(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep) */ p = xdr_inline_decode(xdr, 3 * sizeof(*p)); if (unlikely(!p)) - goto out_short; + return true; rpcrdma_bc_receive_call(r_xprt, rep); return true; - -out_short: - pr_warn("RPC/RDMA short backward direction call\n"); - return true; } #else /* CONFIG_SUNRPC_BACKCHANNEL */ { diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c index 63f8be974df2..4a1edbb4028e 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -2,7 +2,7 @@ /* * Copyright (c) 2015-2018 Oracle. All rights reserved. * - * Support for backward direction RPCs on RPC/RDMA (server-side). + * Support for reverse-direction RPCs on RPC/RDMA (server-side). */ #include @@ -59,7 +59,7 @@ void svc_rdma_handle_bc_reply(struct svc_rqst *rqstp, spin_unlock(&xprt->queue_lock); } -/* Send a backwards direction RPC call. +/* Send a reverse-direction RPC Call. * * Caller holds the connection's mutex and has already marshaled * the RPC/RDMA request. diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index ed1c5444fb9d..fe3be985e239 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -98,9 +98,9 @@ struct rpcrdma_ep { atomic_t re_completion_ids; }; -/* Pre-allocate extra Work Requests for handling backward receives - * and sends. This is a fixed value because the Work Queues are - * allocated when the forward channel is set up, long before the +/* Pre-allocate extra Work Requests for handling reverse-direction + * Receives and Sends. This is a fixed value because the Work Queues + * are allocated when the forward channel is set up, long before the * backchannel is provisioned. This value is two times * NFS4_DEF_CB_SLOT_TABLE_SIZE. */ From patchwork Wed Feb 3 16:24:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12064727 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC7D7C433E6 for ; Wed, 3 Feb 2021 16:25:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8405B64E4D for ; Wed, 3 Feb 2021 16:25:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233614AbhBCQZO (ORCPT ); Wed, 3 Feb 2021 11:25:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:40286 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232550AbhBCQZL (ORCPT ); Wed, 3 Feb 2021 11:25:11 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8793064F93; Wed, 3 Feb 2021 16:24:20 +0000 (UTC) Subject: [PATCH v2 5/6] xprtrdma: Pad optimization, revisited From: Chuck Lever To: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org Date: Wed, 03 Feb 2021 11:24:19 -0500 Message-ID: <161236945965.1030487.13894327853038566730.stgit@manet.1015granger.net> In-Reply-To: <161236925476.1030487.10407536259816633879.stgit@manet.1015granger.net> References: <161236925476.1030487.10407536259816633879.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org The NetApp Linux team discovered that with NFS/RDMA servers that do not support RFC 8797, the Linux client is forming NFSv4.x WRITE requests incorrectly. In this case, the Linux NFS client disables implicit chunk round-up for odd-length Read and Write chunks. The goal was to support old servers that needed that padding to be sent explicitly by clients. In that case the Linux NFS included the tail kvec in the Read chunk, since the tail contains any needed padding. That meant a separate memory registration is needed for the tail kvec, adding to the cost of forming such requests. To avoid that cost for a mere 3 bytes of zeroes that are always ignored by receivers, we try to use implicit roundup when possible. For NFSv4.x, the tail kvec also sometimes contains a trailing GETATTR operation. The Linux NFS clients is unintentionally including that GETATTR operation in the Read chunk as well as inline. Fortunately, servers ignore this craziness and go about their normal business. The fix is simply to /never/ include the tail kvec when forming a data payload Read chunk. Note that since commit 9ed5af268e88 ("SUNRPC: Clean up the handling of page padding in rpc_prepare_reply_pages()") the NFS client passes payload data to the transport with the padding in xdr->pages instead of in the send buffer's tail kvec. So now the Linux NFS client appends XDR padding to all odd-sized Read chunks. This shouldn't be a problem because: - RFC 8166-compliant servers are supposed to work with or without that XDR padding in Read chunks. - Since the padding is now in the same memory region as the data payload, a separate memory registration is not needed. In addition, the link layer extends data in RDMA Read responses to 4-byte boundaries anyway. Thus there is now no savings when the padding is not included. Because older kernels include the payload's XDR padding in the tail kvec, a fix there will be more complicated. Thus backporting this patch is not recommended. Reported by: Olga Kornievskaia Signed-off-by: Chuck Lever Reviewed-By: Tom Talpey --- net/sunrpc/xprtrdma/rpc_rdma.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index f0af89a43efd..f1b52f9ab242 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -257,10 +257,7 @@ rpcrdma_convert_iovs(struct rpcrdma_xprt *r_xprt, struct xdr_buf *xdrbuf, page_base = 0; } - /* When encoding a Read chunk, the tail iovec contains an - * XDR pad and may be omitted. - */ - if (type == rpcrdma_readch && r_xprt->rx_ep->re_implicit_roundup) + if (type == rpcrdma_readch) goto out; /* When encoding a Write chunk, some servers need to see an From patchwork Wed Feb 3 16:24:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12064725 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B411DC433DB for ; Wed, 3 Feb 2021 16:25:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 67A4864E4D for ; Wed, 3 Feb 2021 16:25:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233608AbhBCQZO (ORCPT ); Wed, 3 Feb 2021 11:25:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:40288 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232507AbhBCQZL (ORCPT ); Wed, 3 Feb 2021 11:25:11 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id BF76264E4D; Wed, 3 Feb 2021 16:24:26 +0000 (UTC) Subject: [PATCH v2 6/6] rpcrdma: Capture bytes received in Receive completion tracepoints From: Chuck Lever To: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org Date: Wed, 03 Feb 2021 11:24:25 -0500 Message-ID: <161236946591.1030487.17569515553232560373.stgit@manet.1015granger.net> In-Reply-To: <161236925476.1030487.10407536259816633879.stgit@manet.1015granger.net> References: <161236925476.1030487.10407536259816633879.stgit@manet.1015granger.net> User-Agent: StGit/0.23-29-ga622f1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Signed-off-by: Chuck Lever Acked-By: Tom Talpey --- include/trace/events/rpcrdma.h | 50 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 48 insertions(+), 2 deletions(-) diff --git a/include/trace/events/rpcrdma.h b/include/trace/events/rpcrdma.h index 76e85e16854b..c838e7ac1c2d 100644 --- a/include/trace/events/rpcrdma.h +++ b/include/trace/events/rpcrdma.h @@ -60,6 +60,51 @@ DECLARE_EVENT_CLASS(rpcrdma_completion_class, ), \ TP_ARGS(wc, cid)) +DECLARE_EVENT_CLASS(rpcrdma_receive_completion_class, + TP_PROTO( + const struct ib_wc *wc, + const struct rpc_rdma_cid *cid + ), + + TP_ARGS(wc, cid), + + TP_STRUCT__entry( + __field(u32, cq_id) + __field(int, completion_id) + __field(u32, received) + __field(unsigned long, status) + __field(unsigned int, vendor_err) + ), + + TP_fast_assign( + __entry->cq_id = cid->ci_queue_id; + __entry->completion_id = cid->ci_completion_id; + __entry->status = wc->status; + if (wc->status) { + __entry->received = 0; + __entry->vendor_err = wc->vendor_err; + } else { + __entry->received = wc->byte_len; + __entry->vendor_err = 0; + } + ), + + TP_printk("cq.id=%u cid=%d status=%s (%lu/0x%x) received=%u", + __entry->cq_id, __entry->completion_id, + rdma_show_wc_status(__entry->status), + __entry->status, __entry->vendor_err, + __entry->received + ) +); + +#define DEFINE_RECEIVE_COMPLETION_EVENT(name) \ + DEFINE_EVENT(rpcrdma_receive_completion_class, name, \ + TP_PROTO( \ + const struct ib_wc *wc, \ + const struct rpc_rdma_cid *cid \ + ), \ + TP_ARGS(wc, cid)) + DECLARE_EVENT_CLASS(xprtrdma_reply_class, TP_PROTO( const struct rpcrdma_rep *rep @@ -838,7 +883,8 @@ TRACE_EVENT(xprtrdma_post_linv_err, ** Completion events **/ -DEFINE_COMPLETION_EVENT(xprtrdma_wc_receive); +DEFINE_RECEIVE_COMPLETION_EVENT(xprtrdma_wc_receive); + DEFINE_COMPLETION_EVENT(xprtrdma_wc_send); DEFINE_COMPLETION_EVENT(xprtrdma_wc_fastreg); DEFINE_COMPLETION_EVENT(xprtrdma_wc_li); @@ -1790,7 +1836,7 @@ TRACE_EVENT(svcrdma_post_recv, ) ); -DEFINE_COMPLETION_EVENT(svcrdma_wc_receive); +DEFINE_RECEIVE_COMPLETION_EVENT(svcrdma_wc_receive); TRACE_EVENT(svcrdma_rq_post_err, TP_PROTO(