From: Jack Humphries <jack@chillysky.com>
To: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Cc: users@dpdk.org, Haiyue Wang <haiyue.wang@intel.com>
Subject: Re: Enable RX interrupts
Date: Mon, 1 Nov 2021 01:56:37 -0700 [thread overview]
Message-ID: <8B6D83B4-DF17-4053-88D1-404CBCBB584F@chillysky.com> (raw)
In-Reply-To: <20211101104648.3771e1c4@sovereign>
Hi Dmitry,
Thanks for the quick response! Yes, I was calling rte_eth_dev_rx_intr_enable — I just tried re-arming interrupts before each call to epoll and my initial experiment shows that fixes the issue.
You are right that l3fwd-power does the re-arming as well. If possible, it would be helpful to have a comment in that example code about the re-arming since the impression I got from quickly looking at the l3fwd-power code is that interrupts are turned off because the app wants to poll for a threshold of time before “giving up” and turning interrupts back on again. I’m happy to open a pull request to add this comment, too, if you prefer.
Thanks again for your help!
Jack
> On Nov 1, 2021, at 12:46 AM, Dmitry Kozlyuk <dmitry.kozliuk@gmail.com> wrote:
>
> 2021-10-31 22:50 (UTC-0700), Jack Humphries:
>> Hi folks,
>>
>> Hope all are well. I’m trying to enable interrupts in DPDK so that my network receive thread can sleep on an epoll until packets arrive. I am using the ixgbe kernel driver and igb_uio userspace driver with an Intel 82599ES 10Gbps NIC.
>>
>> I'm doing roughly the following to enable the interrupts, but the epoll never indicates that packets have arrived. The thread only handles packets when the epoll times out. I don't even see interrupts arrive from the device when monitoring /proc/interrupts.
>>
>> port_conf.intr_conf.rxq = 1;
>>
>> ...
>>
>> CHECK_EQ(rte_eth_dev_rx_intr_ctl_q(kPort, kQueue, RTE_EPOLL_PER_THREAD,
>> RTE_INTR_EVENT_ADD, nullptr),
>> 0);
>> CHECK_EQ(rte_eth_dev_rx_intr_enable(kPort, kQueue), 0);
>>
>> ...
>>
>> rte_epoll_event event;
>> while (true) {
>> int n = rte_epoll_wait(RTE_EPOLL_PER_THREAD, &event, /*maxevents=*/1,
>> /*timeout=*/1000);
>> if (n == 0) {
>> // Timeout expired.
>> } else {
>> // Received RX interrupt.
>> }
>> }
>>
>> Given that I don't see anything coming through in /proc/interrupts, I am going to start digging through the ixgbe driver. However, I wanted to ask here first to see if my setup is missing anything obvious. I based it closely on the l3fwd-power example, though I haven't been able to get that example up and running yet since my NIC only has one port plugged in right now and the example requires two (COVID building restrictions).
>>
>> Thanks,
>> Jack Humphries
>
> Hi Jack,
>
> Have you called rte_eth_dev_rx_intr_enable(port_id, queue_id)?
>
> Not sure about ixgbe, but vmxnet3 also requires rearming interrupts with it
> on each iteration before rte_epoll_wait().
> This is what l3fwd-power does by the way (see turn_on_off_intr() function).
>
> + ixgbe maintainer just in case.
next prev parent reply other threads:[~2021-11-01 8:56 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-01 5:50 Jack Humphries
2021-11-01 7:46 ` Dmitry Kozlyuk
2021-11-01 8:56 ` Jack Humphries [this message]
2021-11-06 15:12 ` Thomas Monjalon
2021-11-01 15:20 ` Stephen Hemminger
2021-11-01 19:16 ` Jack Humphries
2021-11-01 19:51 ` Stephen Hemminger
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