From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by dpdk.org (Postfix) with ESMTP id 873681D08E for ; Fri, 15 Jun 2018 15:25:02 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DE99187A81; Fri, 15 Jun 2018 13:25:01 +0000 (UTC) Received: from [10.36.112.38] (ovpn-112-38.ams2.redhat.com [10.36.112.38]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 92A1F2157F42; Fri, 15 Jun 2018 13:25:00 +0000 (UTC) To: Ilya Maximets , dev@dpdk.org, HePeng Cc: Tiwei Bie , Zhihong Wang References: <462941BC-FB45-46BD-8FB2-3455887D6BAB@icloud.com> <20180615123208eucas1p1e5d258f95e9621a31c2fcfbf1f494476~4VVxsfFEy3007530075eucas1p1f@eucas1p1.samsung.com> From: Maxime Coquelin Message-ID: Date: Fri, 15 Jun 2018 15:24:58 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180615123208eucas1p1e5d258f95e9621a31c2fcfbf1f494476~4VVxsfFEy3007530075eucas1p1f@eucas1p1.samsung.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 15 Jun 2018 13:25:01 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 15 Jun 2018 13:25:01 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'maxime.coquelin@redhat.com' RCPT:'' Subject: Re: [dpdk-dev] Missing an increment on vq->log_cache_nb_elem ? X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 15 Jun 2018 13:25:02 -0000 Hi, On 06/15/2018 02:32 PM, Ilya Maximets wrote: >> Hi, >> >> >> In the latest dpdk master branch, in the function *vhost_log_cache_page*: >> >> >> static __rte_always_inline void >> vhost_log_cache_page(struct virtio_net *dev, struct vhost_virtqueue *vq, >> uint64_t page) >> { >> uint32_t bit_nr = page % (sizeof(unsigned long) << 3); >> uint32_t offset = page / (sizeof(unsigned long) << 3); >> int i; >> >> for (i = 0; i < vq->log_cache_nb_elem; i++) { >> struct log_cache_entry *elem = vq->log_cache + i; >> >> if (elem->offset == offset) { >> elem->val |= (1UL << bit_nr); >> return; >> } >> } >> >> if (unlikely(i >= VHOST_LOG_CACHE_NR)) { >> /* >> * No more room for a new log cache entry, >> * so write the dirty log map directly. >> */ >> rte_smp_wmb(); >> vhost_log_page((uint8_t *)(uintptr_t)dev->log_base, page); >> >> return; >> } >> >> vq->log_cache[i].offset = offset; >> vq->log_cache[i].val = (1UL << bit_nr); >> } >> >> Did it just miss an increment on vq->log_cache_nb_elem ? > > Hi. Thanks for pointing that. > > I looked through the code and I see no updates of 'vq->log_cache_nb_elem'. > Looks like it always equal to initial zero value. > > Maxime, I'm afraid that this means that currently pages logging is not > performed at all. Could you please check? > > Best regards, Ilya Maximets. > Thanks Ilya for the heads-up and HePeng for reporting the issue. It is broken indeed... We didn't noticed corruption when running our non-reg tests, I guess they have to be improved. I will post a patch shortly to fix this. HePeng, how does your name spells in the form "$firstname $lastname"? I would need this info to credit you for reporting the issue. Regards, Maxime