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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 On 2/6/24 11:29, David Marchand wrote: > On Wed, Jan 31, 2024 at 8:53 PM Maxime Coquelin > wrote: >> >> When vIOMMU is enabled and Virtio device is bound to kernel >> driver in guest, rte_vhost_dequeue_burst() will often return >> early because of IOTLB misses. > > In theory, we can hit this issue with a dpdk pmd too, as long as the > vIOMMU is in use. > But the consequence would be a "really small" leak which does not have > the same impact as what was seen with the kernel driver which > maps/unmaps pages associated with virtio-net skb way more often :-). > So maybe rephrase this part emphasizing on the kernel case like: > > """ > When vIOMMU is enabled, rte_vhost_dequeue_burst() can return early > because of IOTLB misses. > Such IOTLB misses are especially frequent when a Virtio device is > bound to a kernel driver in guest. > """ Thanks, I agree with your suggestion, Virtio PMD is indeed also impacted. >> >> This patch fixes a mbuf leak occurring in this case. >> >> Fixes: 242695f6122a ("vhost: allocate and free packets in bulk in Tx split") >> Cc: stable@dpdk.org >> >> Signed-off-by: Maxime Coquelin >> Signed-off-by: David Marchand > > Reviewed-by: David Marchand > >