linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Brad Boyer <flar@allandria.com>
To: Finn Thain <fthain@telegraphics.com.au>
Cc: Arnd Bergmann <arnd@kernel.org>,
	"Song Bao Hua (Barry Song)" <song.bao.hua@hisilicon.com>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
	"arnd@arndb.de" <arnd@arndb.de>,
	"geert@linux-m68k.org" <geert@linux-m68k.org>,
	"funaho@jurai.org" <funaho@jurai.org>,
	"philb@gnu.org" <philb@gnu.org>,
	"corbet@lwn.net" <corbet@lwn.net>,
	"mingo@redhat.com" <mingo@redhat.com>,
	"linux-m68k@lists.linux-m68k.org"
	<linux-m68k@lists.linux-m68k.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] IRQ handlers run with some high-priority interrupts(not NMI) enabled on some platform
Date: Fri, 19 Feb 2021 23:08:08 -0800	[thread overview]
Message-ID: <20210220070808.GA7874@allandria.com> (raw)
In-Reply-To: <264b37c2-527-f0ed-197d-b016a7d16e32@telegraphics.com.au>

On Sat, Feb 20, 2021 at 05:32:30PM +1100, Finn Thain wrote:
> Nope. Interrupt priority masking is there to place an upper bound 
> interrupt latency. That's why this feature is shipping in contemporary 
> hardware (e.g. ARM GIC). If you care about real time workloads on arm64, 
> that may interest you.

I don't know if it's still true today, but in the past there was a very
noticeable difference in timer stability between the 68k macintosh
models with the timer interrupt at IPL 1 as compared to the models
where the timer interrupt was at IPL 6. The ability to preempt the
other interrupt handlers made the difference between a usable clock
and one that was pretty unreliable.

	Brad Boyer
	flar@allandria.com


      reply	other threads:[~2021-02-20  7:09 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-12  1:18 [RFC] IRQ handlers run with some high-priority interrupts(not NMI) enabled on some platform Song Bao Hua (Barry Song)
2021-02-12 22:34 ` Arnd Bergmann
2021-02-12 23:00   ` Song Bao Hua (Barry Song)
2021-02-12 23:05     ` Arnd Bergmann
2021-02-12 23:46       ` Song Bao Hua (Barry Song)
2021-02-13 16:32         ` Arnd Bergmann
2021-02-13 22:18           ` Song Bao Hua (Barry Song)
2021-02-13 23:18           ` Song Bao Hua (Barry Song)
2021-02-14  5:10             ` Finn Thain
2021-02-15 13:06               ` Andy Shevchenko
2021-02-15 22:22                 ` Finn Thain
2021-02-17 22:41               ` Song Bao Hua (Barry Song)
2021-02-18  5:30                 ` Finn Thain
2021-02-18 11:19                   ` Arnd Bergmann
2021-02-18 12:30                     ` Geert Uytterhoeven
2021-02-18 13:59                       ` Arnd Bergmann
2021-02-18 15:38                         ` Geert Uytterhoeven
2021-02-18 22:11                     ` Michael Schmitz
2021-02-19  8:10                       ` Geert Uytterhoeven
2021-02-19 22:30                         ` Brad Boyer
2021-02-20  6:32                     ` Finn Thain
2021-02-20  7:08                       ` Brad Boyer [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210220070808.GA7874@allandria.com \
    --to=flar@allandria.com \
    --cc=arnd@arndb.de \
    --cc=arnd@kernel.org \
    --cc=corbet@lwn.net \
    --cc=fthain@telegraphics.com.au \
    --cc=funaho@jurai.org \
    --cc=geert@linux-m68k.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-m68k@lists.linux-m68k.org \
    --cc=mingo@redhat.com \
    --cc=philb@gnu.org \
    --cc=song.bao.hua@hisilicon.com \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).