From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Mike Galbraith <efault@gmx.de>
Cc: Clark Williams <williams@redhat.com>,
"g.medini" <g.medini@eurosoft.it>,
RT <linux-rt-users@vger.kernel.org>
Subject: Re: High latency of a system based on 5.19 rt
Date: Mon, 2 Oct 2023 16:16:11 +0200 [thread overview]
Message-ID: <20231002141611.f1H8qyiR@linutronix.de> (raw)
In-Reply-To: <8586b9812dccc6248e0518efaf973c4467324b70.camel@gmx.de>
On 2023-10-02 13:58:57 [+0200], Mike Galbraith wrote:
> > Why not perform all wakes from hardirq then?
>
> Sounds good to me iff we're talking about a dinky irq width delta.
>
> Threads bundling up what are otherwise irq context cycles is loaded
> with goodness, but static priority leaves you holding a bill and paying
> context switch fees on top. Pick your poison carefully applies I
> suppose. A tiny swig of hemlock can't do _too_ much harm, right ;-)
A swarm of wake-ups for SCHED_OTHER at prio 50+ will delay your threaded
interrupt handler and everything else that runs 50 and lower.
Since SCHED_OTHER is less important than any RT task, the delay is
usually of lower concern.
> -Mike
Sebastian
next prev parent reply other threads:[~2023-10-02 14:16 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-25 16:30 High latency of a system based on 5.19 rt g.medini
2023-09-25 17:02 ` Ralf Mardorf
2023-09-26 7:04 ` Mike Galbraith
2023-09-26 12:34 ` Clark Williams
[not found] ` <CAMLffL8=zW0Bv47R=r3=Lh9==OjDrM=FTJZgmm6PYGOyTedeBA@mail.gmail.com>
2023-09-26 13:15 ` Mike Galbraith
2023-10-02 10:05 ` Sebastian Andrzej Siewior
2023-10-02 11:58 ` Mike Galbraith
2023-10-02 14:16 ` Sebastian Andrzej Siewior [this message]
2023-10-02 15:20 ` Mike Galbraith
2023-10-02 10:02 ` Sebastian Andrzej Siewior
-- strict thread matches above, loose matches on Subject: below --
2023-10-03 13:47 g.medini
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