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 7FEBDA00C3; Tue, 20 Sep 2022 09:24:06 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 1FD6340DFB; Tue, 20 Sep 2022 09:24:06 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by mails.dpdk.org (Postfix) with ESMTP id 884BB4069B for ; Tue, 20 Sep 2022 09:24:04 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1663658644; 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: in-reply-to:in-reply-to:references:references; bh=nscfg7oRh+6xHwFpTwLpB6NYAgTKSu7QCd5t0tgI5NY=; b=QvFY73wH05jlo/FJhmQ2PV/8ljWOxIx6yycBOsnZfiL0S/udiOkRDiJcMLyP4rrhjLxnbf hIj6sOdo9W+f8RkOs7GehddZ1fhWo9N85CkbVYKm4jp3L47xPCFMv06Q4RfTM8fnVK+8KM +sYd6iWScYRbT31faAoMHiwRBJM3W5w= 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-31-g6zsyJeZOYCyZf8oXXFtfQ-1; Tue, 20 Sep 2022 03:24:00 -0400 X-MC-Unique: g6zsyJeZOYCyZf8oXXFtfQ-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8D1C585A5A6; Tue, 20 Sep 2022 07:24:00 +0000 (UTC) Received: from [10.39.208.16] (unknown [10.39.208.16]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C63FF492B0C; Tue, 20 Sep 2022 07:23:59 +0000 (UTC) Message-ID: Date: Tue, 20 Sep 2022 09:23:58 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.0 Subject: Re: [PATCH] vhost: use try_lock in rte_vhost_vring_call To: "Xia, Chenbo" , "Liu, Changpeng" , "dev@dpdk.org" References: <20220906022225.17215-1-changpeng.liu@intel.com> From: Maxime Coquelin In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 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: 7bit 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 On 9/20/22 04:53, Xia, Chenbo wrote: >> -----Original Message----- >> From: Liu, Changpeng >> Sent: Tuesday, September 20, 2022 10:34 AM >> To: Xia, Chenbo ; dev@dpdk.org >> Cc: Maxime Coquelin >> Subject: RE: [PATCH] vhost: use try_lock in rte_vhost_vring_call >> >> Hi Bo, >> >>> -----Original Message----- >>> From: Xia, Chenbo >>> Sent: Tuesday, September 20, 2022 10:25 AM >>> To: Liu, Changpeng ; dev@dpdk.org >>> Cc: Maxime Coquelin >>> Subject: RE: [PATCH] vhost: use try_lock in rte_vhost_vring_call >>> >>> Hi Changpeng, >>> >>>> -----Original Message----- >>>> From: Liu, Changpeng >>>> Sent: Tuesday, September 6, 2022 10:22 AM >>>> To: dev@dpdk.org >>>> Cc: Liu, Changpeng ; Maxime Coquelin >>>> ; Xia, Chenbo >>>> Subject: [PATCH] vhost: use try_lock in rte_vhost_vring_call >>>> >>>> Note that this function is in data path, so the thread context >>>> may not same as socket messages processing context, by using >>>> try_lock here, users can have another try in case of VQ's access >>>> lock is held by `vhost-events` thread. >>> >>> Better to describe the issue this patch wants to fix and how does >>> it fix. >>> >>> I remember it's a bz issue, do you want to backport? And it has >>> some bz ID, we need to add it in commit message. >> Actually it's my intention not to add bz ID, as I think for this bz ID, >> It's better not to lock all VQ's access lock for KICK/CALLFD messages, > > Do you plan to add this change? I think that may be an improvement to current > locking implementation. > > Maxime, what do you think of this idea about only locking specific queue when > handling vring related message (not global config like mem table)? I think this is not a good idea. For example SET_VRING_KICK can currently call translate_ring_addresses(), which itself can call numa_realloc(). numa_realloc() may reallocate the dev, so you don't want it to be used by other queues while it happens. >> What do you think? If this is identified as a fix, I can backport it to >> 22.05. > > You can decide, if this is planned to be the fix, just backport. I am just > thinking if this is not the fix for the bz, do we still need this? > > Thanks, > Chenbo > >>> >>>> >>>> Signed-off-by: Changpeng Liu >>>> --- >>>> lib/vhost/vhost.c | 6 +++++- >>>> 1 file changed, 5 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c >>>> index 60cb05a0ff..072d2acb7b 100644 >>>> --- a/lib/vhost/vhost.c >>>> +++ b/lib/vhost/vhost.c >>>> @@ -1329,7 +1329,11 @@ rte_vhost_vring_call(int vid, uint16_t >> vring_idx) >>>> if (!vq) >>>> return -1; >>>> >>>> - rte_spinlock_lock(&vq->access_lock); >>>> + if (!rte_spinlock_trylock(&vq->access_lock)) { >>>> + VHOST_LOG_CONFIG(dev->ifname, DEBUG, >>> >>> Should use VHOST_LOG_DATA >> OK. >>> >>> Thanks, >>> Chenbo >>> >>>> + "failed to kick guest, virtqueue busy.\n"); >>>> + return -1; >>>> + } >>>> >>>> if (vq_is_packed(dev)) >>>> vhost_vring_call_packed(dev, vq); >>>> -- >>>> 2.21.3 >