From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id A16C7A0579; Wed, 7 Apr 2021 11:51:57 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 24D04407FF; Wed, 7 Apr 2021 11:51:57 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by mails.dpdk.org (Postfix) with ESMTP id D1B404013F for ; Wed, 7 Apr 2021 11:51:55 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617789114; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=Va4fS3UlKQrSzCZyxCr+uzNHK/tlvyjJrGEx9rAMvMw=; b=Itk8rjzK8PUho4f3hO9hwTeuD8hwiChTcUZZ+MIFR2rAVVP9OzhTPNfzIlvctPoQDqZTUb Es07oxTidhYaWPiNWRQgGzeC3+uRmBF6DnCbd6mlAAtxWsCN8T2dpsk424dNL1ZmZqOjBp q/PNr5xHxA5ZMiSi5zDWvWtDJKSYhZY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-565--hVpJj7dM22952btnXKEEg-1; Wed, 07 Apr 2021 05:51:53 -0400 X-MC-Unique: -hVpJj7dM22952btnXKEEg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 49CD2807352 for ; Wed, 7 Apr 2021 09:51:52 +0000 (UTC) Received: from bnemeth.users.ipa.redhat.com (ovpn-114-106.ams2.redhat.com [10.36.114.106]) by smtp.corp.redhat.com (Postfix) with ESMTP id 024A570F5B; Wed, 7 Apr 2021 09:51:49 +0000 (UTC) From: Balazs Nemeth To: bnemeth@redhat.com, dev@dpdk.org Date: Wed, 7 Apr 2021 11:51:44 +0200 Message-Id: <8b9b42cf2b18feb41c4b64a174ccc154847c59f9.1617789063.git.bnemeth@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=bnemeth@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Subject: [dpdk-dev] [PATCH v2] vhost: read last used index once X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Instead of calculating the address of a packed descriptor based on the vq->desc_packed and vq->last_used_idx every time, store that base address in desc_base. On arm, this saves 176 bytes in code size of function in which vhost_flush_enqueue_batch_packed gets inlined. Signed-off-by: Balazs Nemeth --- lib/librte_vhost/virtio_net.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c index 179c57b46..f091384a6 100644 --- a/lib/librte_vhost/virtio_net.c +++ b/lib/librte_vhost/virtio_net.c @@ -217,6 +217,8 @@ vhost_flush_enqueue_batch_packed(struct virtio_net *dev, { uint16_t i; uint16_t flags; + uint16_t last_used_idx = vq->last_used_idx; + struct vring_packed_desc *desc_base = &vq->desc_packed[last_used_idx]; if (vq->shadow_used_idx) { do_data_copy_enqueue(dev, vq); @@ -226,16 +228,17 @@ vhost_flush_enqueue_batch_packed(struct virtio_net *dev, flags = PACKED_DESC_ENQUEUE_USED_FLAG(vq->used_wrap_counter); vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) { - vq->desc_packed[vq->last_used_idx + i].id = ids[i]; - vq->desc_packed[vq->last_used_idx + i].len = lens[i]; + desc_base[i].id = ids[i]; + desc_base[i].len = lens[i]; } rte_atomic_thread_fence(__ATOMIC_RELEASE); - vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) - vq->desc_packed[vq->last_used_idx + i].flags = flags; + vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) { + desc_base[i].flags = flags; + } - vhost_log_cache_used_vring(dev, vq, vq->last_used_idx * + vhost_log_cache_used_vring(dev, vq, last_used_idx * sizeof(struct vring_packed_desc), sizeof(struct vring_packed_desc) * PACKED_BATCH_SIZE); -- 2.30.2