From: Stephen Hemminger <stephen@networkplumber.org>
To: "Morten Brørup" <mb@smartsharesystems.com>
Cc: "Thomas Monjalon" <thomas@monjalon.net>,
<bruce.richardson@intel.com>, <dev@dpdk.org>,
"David Marchand" <david.marchand@redhat.com>
Subject: Re: [PATCH v3 0/2] allow creating thread with real-time priority
Date: Thu, 26 Oct 2023 09:28:40 -0700 [thread overview]
Message-ID: <20231026092840.71f0772b@hermes.local> (raw)
In-Reply-To: <98CBD80474FA8B44BF855DF32C47DC35E9EF9B@smartserver.smartshare.dk>
On Thu, 26 Oct 2023 16:08:02 +0200
Morten Brørup <mb@smartsharesystems.com> wrote:
> > > In our recent tests, nanosleep() itself took around 50 us. So you need to
> > sleep longer than that for your thread not to be runnable when the nanosleep()
> > wakes up again, because 50 us has already passed in "nanosleep overhead".
> > > 10 milliseconds provides plenty of margin, and corresponds to 10 jiffies on
> > a 1000 Hz kernel. (I don't know if it makes any difference for the kernel
> > scheduler if the timer crosses a jiffy border or not.)
> >
> > 10 ms looks like an eternity.
>
> Agree. It is only for functional testing, not for production!
To be safe the sleep has to be longer than the system clock tick.
Most systems are built today with HZ=250 but really should be using HZ=1000
on modern CPU's.
next prev parent reply other threads:[~2023-10-26 16:28 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-24 12:54 [PATCH] eal/unix: " 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
2023-10-25 16:31 ` [PATCH v3 0/2] " Thomas Monjalon
2023-10-25 16:31 ` [PATCH v3 1/2] eal: add thread yield functions Thomas Monjalon
2023-10-25 16:40 ` Bruce Richardson
2023-10-25 17:06 ` Thomas Monjalon
2023-10-25 18:07 ` Morten Brørup
2023-10-25 16:31 ` [PATCH v3 2/2] eal/unix: allow creating thread with real-time priority Thomas Monjalon
2023-10-26 13:36 ` [PATCH v3 0/2] " Thomas Monjalon
2023-10-26 13:44 ` Morten Brørup
2023-10-26 13:57 ` Morten Brørup
2023-10-26 14:04 ` Thomas Monjalon
2023-10-26 14:08 ` Morten Brørup
2023-10-26 14:30 ` Thomas Monjalon
2023-10-26 14:50 ` Morten Brørup
2023-10-26 14:59 ` Morten Brørup
2023-10-26 15:54 ` Bruce Richardson
2023-10-26 16:07 ` Thomas Monjalon
2023-10-26 16:50 ` Morten Brørup
2023-10-26 19:51 ` Thomas Monjalon
2023-10-27 7:19 ` Morten Brørup
2023-10-26 16:28 ` Stephen Hemminger [this message]
2023-10-26 19:55 ` Thomas Monjalon
2023-10-26 21:10 ` Stephen Hemminger
2023-10-26 14:10 ` David Marchand
2023-10-26 13:37 ` [PATCH v4 " Thomas Monjalon
2023-10-26 13:37 ` [PATCH v4 1/2] eal: add thread yield functions Thomas Monjalon
2023-10-26 13:37 ` [PATCH v4 2/2] eal/unix: allow creating thread with real-time priority Thomas Monjalon
2023-10-26 14:19 ` [PATCH v5 0/2] " Thomas Monjalon
2023-10-26 14:19 ` [PATCH v5 1/2] eal: add thread yield functions Thomas Monjalon
2023-10-26 14:19 ` [PATCH v5 2/2] eal/unix: allow creating thread with real-time priority Thomas Monjalon
2023-10-26 20:00 ` [PATCH v5 0/2] " Thomas Monjalon
2023-10-26 23:35 ` Tyler Retzlaff
2023-10-27 8:08 ` [PATCH v6 1/1] eal/unix: " Thomas Monjalon
2023-10-27 8:45 ` Morten Brørup
2023-10-27 9:11 ` Thomas Monjalon
2023-10-27 18:15 ` Stephen Hemminger
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