From: "Loftus, Ciara" <ciara.loftus@intel.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"Ye, Xiaolong" <xiaolong.ye@intel.com>,
"Laatz, Kevin" <kevin.laatz@intel.com>,
"Richardson, Bruce" <bruce.richardson@intel.com>
Subject: Re: [dpdk-dev] [PATCH v2 2/3] net/af_xdp: support pinning of IRQs
Date: Thu, 3 Oct 2019 13:23:07 +0000 [thread overview]
Message-ID: <74F120C019F4A64C9B78E802F6AD4CC279226C6C@IRSMSX106.ger.corp.intel.com> (raw)
In-Reply-To: <20190930101137.4919f93e@hermes.lan>
> -----Original Message-----
> From: Stephen Hemminger <stephen@networkplumber.org>
> Sent: Monday 30 September 2019 18:12
> To: Loftus, Ciara <ciara.loftus@intel.com>
> Cc: dev@dpdk.org; Ye, Xiaolong <xiaolong.ye@intel.com>; Laatz, Kevin
> <kevin.laatz@intel.com>; Richardson, Bruce <bruce.richardson@intel.com>
> Subject: Re: [dpdk-dev] [PATCH v2 2/3] net/af_xdp: support pinning of IRQs
>
> On Mon, 30 Sep 2019 16:42:04 +0000
> Ciara Loftus <ciara.loftus@intel.com> wrote:
>
> > +/* drivers supported for the queue_irq option */
> > +enum supported_drivers {
> > + I40E_DRIVER,
> > + IXGBE_DRIVER,
> > + MLX5_DRIVER,
> > + NUM_DRIVERS
> > +};
>
> Anything device specific like this raises a red flag to me.
>
> This regex etc, seems like a huge hack. Is there a better way using
> irqbalance and smp_affinity in kernel drivers?
>
> NACK
Hi Stephen,
Thanks for looking at the patch. I understand your concern however unfortunately I haven't been able to identify a way to achieve the desired outcome by using your suggestions of irqbalance and smp_affinity. Did you have something specific in mind or are aware of any generic way of retrieving interrupt numbers for NICs regardless of vendor or range?
I think this feature is really important for the usability of this PMD. Without it, to configure the IRQs the user has to open up /proc/interrupts, trawl through it and identify the correct IRQ number for their given NIC and qid (the format for which is unlikely to be known off-hand), and manually pin them by writing the appropriate values in the appropriate format to the appropriate file - prone to error if not automated IMO.
If the user fails to set the affinity it's probably fine for a single pmd, however with multiple pmds all irqs will by default land on core 0 and lead to terrible performance.
It should be possible to rework the code to remove the regexes and use a direct string compare. Would that make the solution more palatable?
Let me know what you think.
Thanks,
Ciara
next prev parent reply other threads:[~2019-10-03 13:23 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-30 16:42 [dpdk-dev] [PATCH v2 0/3] AF_XDP tx halt fix, IRQ pinning and unaligned chunks Ciara Loftus
2019-09-30 16:42 ` [dpdk-dev] [PATCH v2 1/3] net/af_xdp: fix Tx halt when no recv packets Ciara Loftus
2019-10-22 5:32 ` Ye Xiaolong
2019-09-30 16:42 ` [dpdk-dev] [PATCH v2 2/3] net/af_xdp: support pinning of IRQs Ciara Loftus
2019-09-30 17:11 ` Stephen Hemminger
2019-10-03 13:23 ` Loftus, Ciara [this message]
2019-10-14 14:43 ` Bruce Richardson
2019-10-21 15:24 ` Ferruh Yigit
2019-10-21 15:54 ` Bruce Richardson
2019-10-21 16:02 ` Ferruh Yigit
2019-10-21 16:14 ` Bruce Richardson
2019-10-15 11:14 ` Ray Kinsella
2019-10-21 10:04 ` Loftus, Ciara
2019-10-21 12:52 ` Varghese, Vipin
2019-10-21 13:04 ` Bruce Richardson
2019-10-21 13:11 ` Varghese, Vipin
2019-10-21 13:17 ` Bruce Richardson
2019-10-21 13:45 ` Varghese, Vipin
2019-10-21 13:56 ` Bruce Richardson
2019-10-21 14:06 ` Varghese, Vipin
2019-10-18 23:49 ` Ye Xiaolong
2019-09-30 16:42 ` [dpdk-dev] [PATCH v2 3/3] net/af_xdp: enable support for unaligned umem chunks Ciara Loftus
2019-10-18 23:48 ` Ye Xiaolong
2019-10-22 14:28 ` Ferruh Yigit
2019-10-24 11:10 ` David Marchand
2019-10-24 12:18 ` David Marchand
2019-10-24 14:18 ` Ferruh Yigit
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