Linux MIPS Architecture development
 help / color / mirror / Atom feed
From: Ralf Baechle <ralf@linux-mips.org>
To: Thomas Koeller <thomas@koeller.dyndns.org>
Cc: linux-mips@linux-mips.org
Subject: Re: timer irq setup
Date: Tue, 18 Dec 2007 11:48:34 +0100	[thread overview]
Message-ID: <20071218104834.GA19316@linux-mips.org> (raw)
In-Reply-To: <200712171135.24569.thomas@koeller.dyndns.org>

On Mon, Dec 17, 2007 at 11:35:22AM +0100, Thomas Koeller wrote:

> In arch/mips/kernel/traps.c, per_cpu_trap_init() contains
> code to set up the global cp0_compare_irq variable. Does
> this make sense? I'd say that either the irq setup should
> be moved to trap_init(), or cp0_compare_irq should be
> changed to a per-cpu variable, depending on what the original
> intention was.

Technically it would be legal to route the timer interrupt to a different
interrupt for each of possibly multiple processors, that's why it's done
in per_cpu_trap_init().

Obviously the rest of the code isn't quite there and also to best of my
knowledge all actual implementations use the same interrupt across all
cores.  So something like a global variable and a paranoia check in
per_cpu_trap_init() to ensure all CPUs really use the same interrupt
would seem reasonable.

  Ralf

      reply	other threads:[~2007-12-18 10:54 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-12-17 10:35 timer irq setup Thomas Koeller
2007-12-18 10:48 ` Ralf Baechle [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=20071218104834.GA19316@linux-mips.org \
    --to=ralf@linux-mips.org \
    --cc=linux-mips@linux-mips.org \
    --cc=thomas@koeller.dyndns.org \
    /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