LKML Archive on
help / color / mirror / Atom feed
From: David Miller <>
Subject: Re: [PATCH] genirq: Set initial default irq affinity to just CPU0
Date: Sat, 25 Oct 2008 21:04:12 -0700 (PDT)	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <1224970389.7654.473.camel@pasglop>

From: Benjamin Herrenschmidt <>
Date: Sun, 26 Oct 2008 08:33:09 +1100

> Well, I don't know how you do it but on powerpc, we explicitely fill the
> affinity masks at boot time when we can spread interrupts... Maybe we
> should change it the other way around and limit the mask when we can't ?
> It's hard to tell for sure at this stage.

On sparc64 we look at the cpu mask configured for the interrupt and do
one of two things:

1) If all bits are set, we round robin assign a cpu at IRQ enable time.

2) Else we pick the first bit set in the mask.

One modification I want to make is to make case #1 NUMA aware.

But back to my original wonder, since I've always tipped off of this
generic IRQ layer cpu mask, when was it ever defaulting to zero
and causing the behvaior your powerpc guys actually want? :-)

  reply	other threads:[~2008-10-26  4:04 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-24 15:57 Kumar Gala
2008-10-24 23:18 ` David Miller
2008-10-25 21:33   ` Benjamin Herrenschmidt
2008-10-26  4:04     ` David Miller [this message]
2008-10-26  6:33       ` Benjamin Herrenschmidt
2008-10-27 13:43         ` Kumar Gala
2008-10-27 20:27           ` Benjamin Herrenschmidt
2008-10-27 20:45             ` Kumar Gala

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:

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

  git send-email \ \ \ \ \ \ \ \ \ \ \
    --subject='Re: [PATCH] genirq: Set initial default irq affinity to just CPU0' \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

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).