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 6EF2942987; Wed, 19 Apr 2023 11:35:55 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 41B1E40A79; Wed, 19 Apr 2023 11:35:55 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mails.dpdk.org (Postfix) with ESMTP id 8765E4021F for ; Wed, 19 Apr 2023 11:35:53 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1681896953; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Vb+7QyWfyd5cJM3nFW5QfQjw3//7VUhVAvqfeB3x6k0=; b=Yx2wu4/CelYKG5fYki7EsX35yPwATMjPQzeiw4jqnVIDpDc8igf6avRW0N3nQf/foenBh+ thnG/am4lxEH4d+6hC7eubtRRLPUj1HSdR16e5P+Dlu2U6MfUSBVkq57AEbwmT8dPn88CV ApaP9DRdSThGapDMHd4nr4qG3MwVVYU= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-572-dG2IjqSyNymSRkMQOGTYAA-1; Wed, 19 Apr 2023 05:35:45 -0400 X-MC-Unique: dG2IjqSyNymSRkMQOGTYAA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3BC3A81B54C; Wed, 19 Apr 2023 09:35:45 +0000 (UTC) Received: from [10.39.208.29] (unknown [10.39.208.29]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 56479C16024; Wed, 19 Apr 2023 09:35:42 +0000 (UTC) Message-ID: Date: Wed, 19 Apr 2023 11:35:40 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [RFC 05/27] vhost: add helper for IOTLB entries shared page check To: Mike Pattrick Cc: dev@dpdk.org, david.marchand@redhat.com, chenbo.xia@intel.com, fbl@redhat.com, jasowang@redhat.com, cunming.liang@intel.com, xieyongji@bytedance.com, echaudro@redhat.com, eperezma@redhat.com, amorenoz@redhat.com References: <20230331154259.1447831-1-maxime.coquelin@redhat.com> <20230331154259.1447831-6-maxime.coquelin@redhat.com> From: Maxime Coquelin In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 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 Hi Mike, On 4/17/23 21:39, Mike Pattrick wrote: > Hi Maxime, > > On Fri, Mar 31, 2023 at 11:43 AM Maxime Coquelin > wrote: >> >> This patch introduces a helper to check whether two IOTLB >> entries share a page. >> >> Signed-off-by: Maxime Coquelin >> --- >> lib/vhost/iotlb.c | 25 ++++++++++++++++++++----- >> 1 file changed, 20 insertions(+), 5 deletions(-) >> >> diff --git a/lib/vhost/iotlb.c b/lib/vhost/iotlb.c >> index e8f1cb661e..d919f74704 100644 >> --- a/lib/vhost/iotlb.c >> +++ b/lib/vhost/iotlb.c >> @@ -23,6 +23,23 @@ struct vhost_iotlb_entry { >> >> #define IOTLB_CACHE_SIZE 2048 >> >> +static bool >> +vhost_user_iotlb_share_page(struct vhost_iotlb_entry *a, struct vhost_iotlb_entry *b, >> + uint64_t align) >> +{ >> + uint64_t a_end, b_start; >> + >> + if (a == NULL || b == NULL) >> + return false; >> + >> + /* Assumes entry a lower than entry b */ >> + RTE_ASSERT(a->uaddr < b->uaddr); >> + a_end = RTE_ALIGN_CEIL(a->uaddr + a->size, align); >> + b_start = RTE_ALIGN_FLOOR(b->uaddr, align); >> + >> + return a_end > b_start; > > This may be a very minor detail, but it might improve readability if > the a_end calculation used addr + size - 1 and the return conditional > used >=. That's actually how I initially implemented it, but discussing with David we agreed it would be better that way for consistency with vhost_user_iotlb_clear_dump(). Regards, Maxime > > Cheers, > M > > >> +} >> + >> static void >> vhost_user_iotlb_set_dump(struct virtio_net *dev, struct vhost_iotlb_entry *node) >> { >> @@ -37,16 +54,14 @@ static void >> vhost_user_iotlb_clear_dump(struct virtio_net *dev, struct vhost_iotlb_entry *node, >> struct vhost_iotlb_entry *prev, struct vhost_iotlb_entry *next) >> { >> - uint64_t align, mask; >> + uint64_t align; >> >> align = hua_to_alignment(dev->mem, (void *)(uintptr_t)node->uaddr); >> - mask = ~(align - 1); >> >> /* Don't disable coredump if the previous node is in the same page */ >> - if (prev == NULL || (node->uaddr & mask) != ((prev->uaddr + prev->size - 1) & mask)) { >> + if (!vhost_user_iotlb_share_page(prev, node, align)) { >> /* Don't disable coredump if the next node is in the same page */ >> - if (next == NULL || >> - ((node->uaddr + node->size - 1) & mask) != (next->uaddr & mask)) >> + if (!vhost_user_iotlb_share_page(node, next, align)) >> mem_set_dump((void *)(uintptr_t)node->uaddr, node->size, false, align); >> } >> } >> -- >> 2.39.2 >> >