From: "Kinsella, Ray" <ray.kinsella@intel.com>
To: Antonio Di Bacco <a.dibacco.ks@gmail.com>,
Stephen Hemminger <stephen@networkplumber.org>
Cc: "users@dpdk.org" <users@dpdk.org>
Subject: RE: Large interruptions for EAL thread running on isol core
Date: Fri, 24 Jun 2022 10:43:20 +0000 [thread overview]
Message-ID: <PH0PR11MB4776FE0833EED817471FAEDD90B49@PH0PR11MB4776.namprd11.prod.outlook.com> (raw)
In-Reply-To: <CAO8pfFn8wYs-w=FSH3Xk7+ZRMvxaeHXz12Fow0cFHB-0FHkMpg@mail.gmail.com>
Have you tried testing with Jitter?
Looking through the CSIT data, will give an idea of the reasonable ranges for results.
Intel ICELAKE
https://docs.fd.io/csit/master/report/introduction/test_environment_sut_calib_icx.html
Intel CASCADE LAKE
https://docs.fd.io/csit/master/report/introduction/test_environment_sut_calib_clx.html
Ray K
-----Original Message-----
From: Antonio Di Bacco <a.dibacco.ks@gmail.com>
Sent: Friday 24 June 2022 10:45
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: users@dpdk.org
Subject: Re: Large interruptions for EAL thread running on isol core
Thank you, didn't know that "System management units" could steal CPU!!! That is scary
On Thu, Jun 23, 2022 at 8:42 PM Stephen Hemminger <stephen@networkplumber.org> wrote:
>
> On Thu, 23 Jun 2022 20:03:02 +0200
> Antonio Di Bacco <a.dibacco.ks@gmail.com> wrote:
>
> > I'm running a DPDK thread on an isolated core. I also set some
> > flags that could help keeping the core at rest on linux like:
> > nosoftlockup nohz_full rcu_nocbs irqaffinity.
> >
> > Unfortunately the thread gets some interruptions that stop the
> > thread for about 20-30 micro seconds. This seems smal but my
> > application suffers a lot.
> >
> > I also tried to use rte_thread_set_priority that indeed has a
> > strong effect but unfortunately creates problems to Linux (like
> > network not working).
> >
> > Is there any other knob that could help running the DPDK thread with
> > minimum or no interruptions at all?
>
> Look with perf and see what is happening.
> First check for interrupt affinity.
> Don't try real time priority.
>
> The other thing to look for would be any BIOS settings.
> Some system management units can take away CPU silently for polling
> some internal housekeeping.
next prev parent reply other threads:[~2022-06-24 10:43 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-23 18:03 Antonio Di Bacco
2022-06-23 18:07 ` Omer Yamac
2022-06-24 9:43 ` Antonio Di Bacco
2022-06-23 18:41 ` Stephen Hemminger
2022-06-24 9:45 ` Antonio Di Bacco
2022-06-24 10:43 ` Kinsella, Ray [this message]
2022-06-23 19:03 ` Carsten Andrich
2022-06-24 15:01 ` Stephen Hemminger
2022-06-24 15:41 ` Carsten Andrich
2022-06-24 16:42 ` Stephen Hemminger
2022-06-28 7:25 ` Carsten Andrich
2022-06-28 15:19 ` Stephen Hemminger
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