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Tue, 10 Mar 2020 08:58:18 -0400 X-MC-Unique: deM2UEW9NG2jpVNsawP6Vg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E1259100550D; Tue, 10 Mar 2020 12:58:16 +0000 (UTC) Received: from [10.36.112.43] (ovpn-112-43.ams2.redhat.com [10.36.112.43]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 304A392D20; Tue, 10 Mar 2020 12:58:15 +0000 (UTC) To: "Van Haaren, Harry" , "Ye, Xiaolong" , Itsuro Oda Cc: "dev@dpdk.org" , "Wang, Zhihong" , "stable@dpdk.org" References: <20200310050003.16728-1-oda@valinux.co.jp> <20200310113206.GA14733@intel.com> From: Maxime Coquelin Autocrypt: addr=maxime.coquelin@redhat.com; keydata= mQINBFOEQQIBEADjNLYZZqghYuWv1nlLisptPJp+TSxE/KuP7x47e1Gr5/oMDJ1OKNG8rlNg kLgBQUki3voWhUbMb69ybqdMUHOl21DGCj0BTU3lXwapYXOAnsh8q6RRM+deUpasyT+Jvf3a gU35dgZcomRh5HPmKMU4KfeA38cVUebsFec1HuJAWzOb/UdtQkYyZR4rbzw8SbsOemtMtwOx YdXodneQD7KuRU9IhJKiEfipwqk2pufm2VSGl570l5ANyWMA/XADNhcEXhpkZ1Iwj3TWO7XR uH4xfvPl8nBsLo/EbEI7fbuUULcAnHfowQslPUm6/yaGv6cT5160SPXT1t8U9QDO6aTSo59N jH519JS8oeKZB1n1eLDslCfBpIpWkW8ZElGkOGWAN0vmpLfdyiqBNNyS3eGAfMkJ6b1A24un /TKc6j2QxM0QK4yZGfAxDxtvDv9LFXec8ENJYsbiR6WHRHq7wXl/n8guyh5AuBNQ3LIK44x0 KjGXP1FJkUhUuruGyZsMrDLBRHYi+hhDAgRjqHgoXi5XGETA1PAiNBNnQwMf5aubt+mE2Q5r qLNTgwSo2dpTU3+mJ3y3KlsIfoaxYI7XNsPRXGnZi4hbxmeb2NSXgdCXhX3nELUNYm4ArKBP LugOIT/zRwk0H0+RVwL2zHdMO1Tht1UOFGfOZpvuBF60jhMzbQARAQABtCxNYXhpbWUgQ29x dWVsaW4gPG1heGltZS5jb3F1ZWxpbkByZWRoYXQuY29tPokCOAQTAQIAIgUCV3u/5QIbAwYL CQgHAwIGFQgCCQoLBBYCAwECHgECF4AACgkQyjiNKEaHD4ma2g/+P+Hg9WkONPaY1J4AR7Uf kBneosS4NO3CRy0x4WYmUSLYMLx1I3VH6SVjqZ6uBoYy6Fs6TbF6SHNc7QbB6Qjo3neqnQR1 71Ua1MFvIob8vUEl3jAR/+oaE1UJKrxjWztpppQTukIk4oJOmXbL0nj3d8dA2QgHdTyttZ1H xzZJWWz6vqxCrUqHU7RSH9iWg9R2iuTzii4/vk1oi4Qz7y/q8ONOq6ffOy/t5xSZOMtZCspu Mll2Szzpc/trFO0pLH4LZZfz/nXh2uuUbk8qRIJBIjZH3ZQfACffgfNefLe2PxMqJZ8mFJXc RQO0ONZvwoOoHL6CcnFZp2i0P5ddduzwPdGsPq1bnIXnZqJSl3dUfh3xG5ArkliZ/++zGF1O wvpGvpIuOgLqjyCNNRoR7cP7y8F24gWE/HqJBXs1qzdj/5Hr68NVPV1Tu/l2D1KMOcL5sOrz 2jLXauqDWn1Okk9hkXAP7+0Cmi6QwAPuBT3i6t2e8UdtMtCE4sLesWS/XohnSFFscZR6Vaf3 gKdWiJ/fW64L6b9gjkWtHd4jAJBAIAx1JM6xcA1xMbAFsD8gA2oDBWogHGYcScY/4riDNKXi lw92d6IEHnSf6y7KJCKq8F+Jrj2BwRJiFKTJ6ChbOpyyR6nGTckzsLgday2KxBIyuh4w+hMq TGDSp2rmWGJjASq5Ag0EVPSbkwEQAMkaNc084Qvql+XW+wcUIY+Dn9A2D1gMr2BVwdSfVDN7 0ZYxo9PvSkzh6eQmnZNQtl8WSHl3VG3IEDQzsMQ2ftZn2sxjcCadexrQQv3Lu60Tgj7YVYRM H+fLYt9W5YuWduJ+FPLbjIKynBf6JCRMWr75QAOhhhaI0tsie3eDsKQBA0w7WCuPiZiheJaL 4MDe9hcH4rM3ybnRW7K2dLszWNhHVoYSFlZGYh+MGpuODeQKDS035+4H2rEWgg+iaOwqD7bg CQXwTZ1kSrm8NxIRVD3MBtzp9SZdUHLfmBl/tLVwDSZvHZhhvJHC6Lj6VL4jPXF5K2+Nn/Su CQmEBisOmwnXZhhu8ulAZ7S2tcl94DCo60ReheDoPBU8PR2TLg8rS5f9w6mLYarvQWL7cDtT d2eX3Z6TggfNINr/RTFrrAd7NHl5h3OnlXj7PQ1f0kfufduOeCQddJN4gsQfxo/qvWVB7PaE 1WTIggPmWS+Xxijk7xG6x9McTdmGhYaPZBpAxewK8ypl5+yubVsE9yOOhKMVo9DoVCjh5To5 aph7CQWfQsV7cd9PfSJjI2lXI0dhEXhQ7lRCFpf3V3mD6CyrhpcJpV6XVGjxJvGUale7+IOp sQIbPKUHpB2F+ZUPWds9yyVxGwDxD8WLqKKy0WLIjkkSsOb9UBNzgRyzrEC9lgQ/ABEBAAGJ Ah8EGAECAAkFAlT0m5MCGwwACgkQyjiNKEaHD4nU8hAAtt0xFJAy0sOWqSmyxTc7FUcX+pbD KVyPlpl6urKKMk1XtVMUPuae/+UwvIt0urk1mXi6DnrAN50TmQqvdjcPTQ6uoZ8zjgGeASZg jj0/bJGhgUr9U7oG7Hh2F8vzpOqZrdd65MRkxmc7bWj1k81tOU2woR/Gy8xLzi0k0KUa8ueB iYOcZcIGTcs9CssVwQjYaXRoeT65LJnTxYZif2pfNxfINFzCGw42s3EtZFteczClKcVSJ1+L +QUY/J24x0/ocQX/M1PwtZbB4c/2Pg/t5FS+s6UB1Ce08xsJDcwyOPIH6O3tccZuriHgvqKP yKz/Ble76+NFlTK1mpUlfM7PVhD5XzrDUEHWRTeTJSvJ8TIPL4uyfzhjHhlkCU0mw7Pscyxn DE8G0UYMEaNgaZap8dcGMYH/96EfE5s/nTX0M6MXV0yots7U2BDb4soLCxLOJz4tAFDtNFtA wLBhXRSvWhdBJZiig/9CG3dXmKfi2H+wdUCSvEFHRpgo7GK8/Kh3vGhgKmnnxhl8ACBaGy9n fxjSxjSO6rj4/MeenmlJw1yebzkX8ZmaSi8BHe+n6jTGEFNrbiOdWpJgc5yHIZZnwXaW54QT UhhSjDL1rV2B4F28w30jYmlRmm2RdN7iCZfbyP3dvFQTzQ4ySquuPkIGcOOHrvZzxbRjzMx1 Mwqu3GQ= Message-ID: Date: Tue, 10 Mar 2020 13:58:13 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH] vhost: make iotlb cache name unique among multi processes X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: stable-bounces@dpdk.org Sender: "stable" On 3/10/20 1:44 PM, Van Haaren, Harry wrote: >> -----Original Message----- >> From: dev On Behalf Of Ye Xiaolong >> Sent: Tuesday, March 10, 2020 11:32 AM >> To: Itsuro Oda >> Cc: dev@dpdk.org; maxime.coquelin@redhat.com; Wang, Zhihong >> ; stable@dpdk.org >> Subject: Re: [dpdk-dev] [PATCH] vhost: make iotlb cache name unique among >> multi processes >> >> On 03/10, Itsuro Oda wrote: >>> Currently, iotlb cache name is comprised of vid and virtqueue >>> index. For example, "iotlb_cache_0_0". Because vid is assigned >>> per process, iotlb cache name is not unique among multi processes. >>> For example a secondary process uses a vhost >>> (ex. eth_vhost0,iface=/tmp/sock0) and another secondary process >>> uses a vhost (ex. eth_vhost1,iface=/tmp/sock1), iotlb cache >>> name of both vhost ("iotlb_cache_0_0") are same and as a result >>> iotlb cache is broken. >>> >>> This patch makes iotlb cache name unique among milti processes >>> by using the interface name not vid to comprise iotlb cache name. >>> Since the length of interface name is variable, this patch uses >>> hash value calculated by the interface name. >>> >>> Fixes: d012d1f293f4 (vhost: add IOTLB helper functions) >>> Cc: stable@dpdk.org >>> >>> Signed-off-by: Itsuro Oda >>> --- >>> lib/librte_vhost/iotlb.c | 8 ++++++-- >>> 1 file changed, 6 insertions(+), 2 deletions(-) >>> >>> diff --git a/lib/librte_vhost/iotlb.c b/lib/librte_vhost/iotlb.c >>> index bc1758528..0992c145b 100644 >>> --- a/lib/librte_vhost/iotlb.c >>> +++ b/lib/librte_vhost/iotlb.c >>> @@ -6,6 +6,7 @@ >>> #include >>> #endif >>> >>> +#include >>> #include >>> >>> #include "iotlb.h" >>> @@ -288,6 +289,7 @@ vhost_user_iotlb_init(struct virtio_net *dev, int >> vq_index) >>> char pool_name[RTE_MEMPOOL_NAMESIZE]; >>> struct vhost_virtqueue *vq = dev->virtqueue[vq_index]; >>> int socket = 0; >>> + uint32_t val; >>> >>> if (vq->iotlb_pool) { >>> /* >>> @@ -308,8 +310,10 @@ vhost_user_iotlb_init(struct virtio_net *dev, int >> vq_index) >>> TAILQ_INIT(&vq->iotlb_list); >>> TAILQ_INIT(&vq->iotlb_pending_list); >>> >>> - snprintf(pool_name, sizeof(pool_name), "iotlb_cache_%d_%d", >>> - dev->vid, vq_index); >>> + val = rte_jhash(dev->ifname, strlen(dev->ifname), 0); >>> + snprintf(pool_name, sizeof(pool_name), "iotlb_cache_%08x_%d", >>> + val, vq_index); >>> + VHOST_LOG_CONFIG(DEBUG, "IOTLB cache name: %s\n", pool_name); > > Although very unlikely, what would happen if there is a hash-collision? > > For example imagine two different names hash to the same "val", from > my understanding they will now use the same IOTLB but should not share one. > > > +1. Instead of a hash, maybe use the process ID: snprintf(pool_name, sizeof(pool_name), "iotlb_cache_%u_%d_%d", pid, dev->vid, vq_index);