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From: Stephen Hemminger <stephen@networkplumber.org>
To: "Morten Brørup" <mb@smartsharesystems.com>
Cc: "Thomas Monjalon" <thomas@monjalon.net>, <dev@dpdk.org>,
	"David Marchand" <david.marchand@redhat.com>, <stable@dpdk.org>,
	"Anatoly Burakov" <anatoly.burakov@intel.com>,
	"Tyler Retzlaff" <roretzla@linux.microsoft.com>,
	"Narcisa Vasile" <navasile@linux.microsoft.com>,
	"Dmitry Kozlyuk" <dmitry.kozliuk@gmail.com>,
	"Konstantin Ananyev" <konstantin.v.ananyev@yandex.ru>,
	"Andrew Rybchenko" <andrew.rybchenko@oktetlabs.ru>
Subject: Re: [PATCH v6 1/1] eal/unix: allow creating thread with real-time priority
Date: Fri, 27 Oct 2023 11:15:58 -0700	[thread overview]
Message-ID: <20231027111558.0e2688e2@hermes.local> (raw)
In-Reply-To: <98CBD80474FA8B44BF855DF32C47DC35E9EFA3@smartserver.smartshare.dk>

On Fri, 27 Oct 2023 10:45:03 +0200
Morten Brørup <mb@smartsharesystems.com> wrote:

> Is it 100 % certain that the system becomes unstable if not sleeping or using blocking system calls from a real-time thread?
> And technically, it's not the thread itself that becomes unstable.

My experience is that the goal of real time threads is "do not let kernel have higher priority than this thread".
That means that if/when a kernel worker is needed on this core, instability happens.
It is very hard but possible to ensure that a kernel worker thread never runs on that core.
But if you are able to do configure that, then there is no point in using RT threads.
The best design is to avoid the kernel needing to run, and if it does then let it run.

  parent reply	other threads:[~2023-10-27 18:16 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-24 12:54 [PATCH] " Thomas Monjalon
2023-10-24 13:55 ` Morten Brørup
2023-10-24 16:04   ` Stephen Hemminger
2023-10-25 13:15     ` Thomas Monjalon
2023-10-25 13:34       ` Bruce Richardson
2023-10-25 13:44         ` Thomas Monjalon
2023-10-25 15:08           ` Stephen Hemminger
2023-10-25 15:14             ` Bruce Richardson
2023-10-25 15:18               ` Thomas Monjalon
2023-10-25 15:32                 ` Thomas Monjalon
2023-10-25 15:13 ` [PATCH v2] " Thomas Monjalon
2023-10-25 15:37   ` Stephen Hemminger
2023-10-25 16:46     ` Thomas Monjalon
2023-10-25 17:54       ` Morten Brørup
2023-10-25 21:33         ` Stephen Hemminger
2023-10-26  7:33           ` Morten Brørup
2023-10-26 16:32             ` Stephen Hemminger
2023-10-26 17:07               ` Morten Brørup
2023-10-26  0:00         ` Stephen Hemminger
     [not found] ` <20231025163352.1076755-1-thomas@monjalon.net>
2023-10-25 16:31   ` [PATCH v3 2/2] " Thomas Monjalon
     [not found] ` <20231026134313.1165954-1-thomas@monjalon.net>
2023-10-26 13:37   ` [PATCH v4 " Thomas Monjalon
     [not found] ` <20231026142749.1174372-1-thomas@monjalon.net>
2023-10-26 14:19   ` [PATCH v5 " Thomas Monjalon
2023-10-27  8:08 ` [PATCH v6 1/1] " Thomas Monjalon
2023-10-27  8:45   ` Morten Brørup
2023-10-27  9:11     ` Thomas Monjalon
2023-10-27 18:15     ` Stephen Hemminger [this message]
2024-10-07 19:27   ` Stephen Hemminger

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