[v2,0/5] vhost: I-cache pressure optimizations
Message ID | 20190517150613.13310-1-maxime.coquelin@redhat.com (mailing list archive) |
---|---|
Headers |
Return-Path: <dev-bounces@dpdk.org> X-Original-To: patchwork@dpdk.org Delivered-To: patchwork@dpdk.org Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id CE2606CD8; Fri, 17 May 2019 17:06:28 +0200 (CEST) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 2C0416904 for <dev@dpdk.org>; Fri, 17 May 2019 17:06:28 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 66F02C00DDF9; Fri, 17 May 2019 15:06:26 +0000 (UTC) Received: from localhost.localdomain (ovpn-112-59.ams2.redhat.com [10.36.112.59]) by smtp.corp.redhat.com (Postfix) with ESMTP id D6F51124F5C; Fri, 17 May 2019 15:06:15 +0000 (UTC) From: Maxime Coquelin <maxime.coquelin@redhat.com> To: dev@dpdk.org, tiwei.bie@intel.com, jfreimann@redhat.com, zhihong.wang@intel.com, bruce.richardson@intel.com, konstantin.ananyev@intel.com, david.marchand@redhat.com Cc: Maxime Coquelin <maxime.coquelin@redhat.com> Date: Fri, 17 May 2019 17:06:08 +0200 Message-Id: <20190517150613.13310-1-maxime.coquelin@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Fri, 17 May 2019 15:06:27 +0000 (UTC) Subject: [dpdk-dev] [PATCH v2 0/5] vhost: I-cache pressure optimizations X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <https://mails.dpdk.org/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://mails.dpdk.org/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <https://mails.dpdk.org/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> Errors-To: dev-bounces@dpdk.org Sender: "dev" <dev-bounces@dpdk.org> |
Message
Maxime Coquelin
May 17, 2019, 3:06 p.m. UTC
Some OVS-DPDK PVP benchmarks show a performance drop when switching from DPDK v17.11 to v18.11. With the addition of packed ring layout support, rte_vhost_enqueue_burst and rte_vhost_dequeue_burst became very large, and only a part of the instructions are executed (either packed or split ring used). This series aims at improving the I-cache pressure, first by un-inlining split and packed rings, but also by moving parts considered as cold in dedicated functions (dirty page logging, fragmented descriptors buffer management added for CVE-2018-1059). With the series applied, size of the enqueue and dequeue split paths is reduced significantly: +---------+--------------------+---------------------+ | Version | Enqueue split path | Dequeue split path | +---------+--------------------+---------------------+ | v19.05 | 16461B | 25521B | | +series | 7286B | 11285B | +---------+--------------------+---------------------+ Using perf tool to monitor iTLB-load-misses event while doing PVP benchmark with testpmd as vswitch, we can see the number of iTLB misses being reduced: - v19.05: # perf stat --repeat 10 -C 2,3 -e iTLB-load-miss -- sleep 10 Performance counter stats for 'CPU(s) 2,3' (10 runs): 2,438 iTLB-load-miss ( +- 13.43% ) 10.00058928 +- 0.00000336 seconds time elapsed ( +- 0.00% ) - +series: # perf stat --repeat 10 -C 2,3 -e iTLB-load-miss -- sleep 10 Performance counter stats for 'CPU(s) 2,3' (10 runs): 55 iTLB-load-miss ( +- 10.08% ) 10.00059466 +- 0.00000283 seconds time elapsed ( +- 0.00% ) The series also force the inlining of some rte_memcpy helpers, as by adding packed ring support, some of them were not more inlined but embedded as functions in the virtio_net object file, which was not expected. Finally, the series simplifies the descriptors buffers prefetching, by doing it in the recently introduced descriptor buffer mapping function. v2: === - Fix checkpatch issue - Reset author for patch 5 (David) - Force non-inlining in patch 2 (David) - Fix typo in path 3 commit message (David) Maxime Coquelin (5): vhost: un-inline dirty pages logging functions vhost: do not inline packed and split functions vhost: do not inline unlikely fragmented buffers code vhost: simplify descriptor's buffer prefetching eal/x86: force inlining of all memcpy and mov helpers .../common/include/arch/x86/rte_memcpy.h | 18 +- lib/librte_vhost/vhost.c | 165 ++++++++++++++++++ lib/librte_vhost/vhost.h | 164 ++--------------- lib/librte_vhost/virtio_net.c | 143 +++++++-------- 4 files changed, 251 insertions(+), 239 deletions(-)