From mboxrd@z Thu Jan 1 00:00:00 1970 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=-16.7 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,USER_AGENT_GIT 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 2D570C4338F for ; Sat, 31 Jul 2021 14:03:29 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DB2EA6054E for ; Sat, 31 Jul 2021 14:03:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org DB2EA6054E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=cn.fujitsu.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:33002 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m9paK-0002MS-0i for qemu-devel@archiver.kernel.org; Sat, 31 Jul 2021 10:03:28 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39538) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m9pWD-0006tq-Pw for qemu-devel@nongnu.org; Sat, 31 Jul 2021 09:59:13 -0400 Received: from mail.cn.fujitsu.com ([183.91.158.132]:34144 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m9pWB-00014z-4v for qemu-devel@nongnu.org; Sat, 31 Jul 2021 09:59:13 -0400 IronPort-HdrOrdr: =?us-ascii?q?A9a23=3AkbAv2q0AlvgckH8gpeAY4gqjBI4kLtp133Aq?= =?us-ascii?q?2lEZdPU1SL39qynKppkmPHDP5gr5J0tLpTntAsi9qBDnhPtICOsqTNSftWDd0Q?= =?us-ascii?q?PGEGgI1/qB/9SPIU3D398Y/aJhXow7M9foEGV95PyQ3CCIV/om3/mLmZrFudvj?= X-IronPort-AV: E=Sophos;i="5.84,284,1620662400"; d="scan'208";a="112154386" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 31 Jul 2021 21:59:08 +0800 Received: from G08CNEXMBPEKD04.g08.fujitsu.local (unknown [10.167.33.201]) by cn.fujitsu.com (Postfix) with ESMTP id 685DC4D0D480; Sat, 31 Jul 2021 21:59:05 +0800 (CST) Received: from G08CNEXCHPEKD09.g08.fujitsu.local (10.167.33.85) by G08CNEXMBPEKD04.g08.fujitsu.local (10.167.33.201) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Sat, 31 Jul 2021 21:59:00 +0800 Received: from localhost.localdomain (10.167.225.141) by G08CNEXCHPEKD09.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.23 via Frontend Transport; Sat, 31 Jul 2021 21:58:59 +0800 From: Li Zhijian To: , , Subject: [PATCH 2/2] migration/rdma: advise prefetch write for ODP region Date: Sat, 31 Jul 2021 22:03:32 +0800 Message-ID: <20210731140332.8701-3-lizhijian@cn.fujitsu.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210731140332.8701-1-lizhijian@cn.fujitsu.com> References: <20210731140332.8701-1-lizhijian@cn.fujitsu.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-yoursite-MailScanner-ID: 685DC4D0D480.AF421 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: lizhijian@fujitsu.com Received-SPF: neutral client-ip=183.91.158.132; envelope-from=lizhijian@fujitsu.com; helo=heian.cn.fujitsu.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NEUTRAL=0.779 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Li Zhijian Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The responder mr registering with ODP will sent RNR NAK back to the requester in the face of the page fault. --------- ibv_poll_cq wc.status=13 RNR retry counter exceeded! ibv_poll_cq wrid=WRITE RDMA! --------- ibv_advise_mr(3) helps to make pages present before the actual IO is conducted so that the responder does page fault as little as possible. Signed-off-by: Li Zhijian --- migration/rdma.c | 40 ++++++++++++++++++++++++++++++++++++++++ migration/trace-events | 1 + 2 files changed, 41 insertions(+) diff --git a/migration/rdma.c b/migration/rdma.c index 8784b5f22a6..a2ad00d665f 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -1117,6 +1117,30 @@ static int qemu_rdma_alloc_qp(RDMAContext *rdma) return 0; } +/* + * ibv_advise_mr to avoid RNR NAK error as far as possible. + * The responder mr registering with ODP will sent RNR NAK back to + * the requester in the face of the page fault. + */ +static void qemu_rdma_advise_prefetch_write_mr(struct ibv_pd *pd, uint64_t addr, + uint32_t len, uint32_t lkey, + const char *name, bool wr) +{ + int ret; + int advice = wr ? IBV_ADVISE_MR_ADVICE_PREFETCH_WRITE : + IBV_ADVISE_MR_ADVICE_PREFETCH; + struct ibv_sge sg_list = {.lkey = lkey, .addr = addr, .length = len}; + + ret = ibv_advise_mr(pd, advice, + IB_UVERBS_ADVISE_MR_FLAG_FLUSH, &sg_list, 1); + /* ignore the error */ + if (ret) { + trace_qemu_rdma_advise_mr(name, len, addr, strerror(errno)); + } else { + trace_qemu_rdma_advise_mr(name, len, addr, "successed"); + } +} + static int qemu_rdma_reg_whole_ram_blocks(RDMAContext *rdma) { int i; @@ -1140,6 +1164,17 @@ on_demand: perror("Failed to register local dest ram block!\n"); break; } + + if (access & IBV_ACCESS_ON_DEMAND) { + qemu_rdma_advise_prefetch_write_mr(rdma->pd, + (uintptr_t) + local->block[i].local_host_addr, + local->block[i].length, + local->block[i].mr->lkey, + local->block[i].block_name, + true); + } + rdma->total_registrations++; } @@ -1244,6 +1279,11 @@ on_demand: rdma->total_registrations); return -1; } + if (access & IBV_ACCESS_ON_DEMAND) { + qemu_rdma_advise_prefetch_write_mr(rdma->pd, (uintptr_t)chunk_start, + len, block->pmr[chunk]->lkey, + block->block_name, rkey); + } rdma->total_registrations++; } diff --git a/migration/trace-events b/migration/trace-events index 5f6aa580def..901c1d54c12 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -213,6 +213,7 @@ qemu_rdma_poll_other(const char *compstr, int64_t comp, int left) "other complet qemu_rdma_post_send_control(const char *desc) "CONTROL: sending %s.." qemu_rdma_register_and_get_keys(uint64_t len, void *start) "Registering %" PRIu64 " bytes @ %p" qemu_rdma_register_odp_mr(const char *name) "Try to register On-Demand Paging memory region: %s" +qemu_rdma_advise_mr(const char *name, uint32_t len, uint64_t addr, const char *res) "Try to advise block %s prefetch write at %" PRIu32 "@0x%" PRIx64 ": %s" qemu_rdma_registration_handle_compress(int64_t length, int index, int64_t offset) "Zapping zero chunk: %" PRId64 " bytes, index %d, offset %" PRId64 qemu_rdma_registration_handle_finished(void) "" qemu_rdma_registration_handle_ram_blocks(void) "" -- 2.31.1