public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: ebiederm@xmission.com (Eric W. Biederman)
To: Linus Torvalds <torvalds@osdl.org>
Cc: Andrew Morton <akpm@osdl.org>, Andi Kleen <ak@suse.de>,
	<linux-kernel@vger.kernel.org>,
	Natalie Protasevich <Natalie.Protasevich@UNISYS.com>,
	Yinghai Lu <yinghai.lu@amd.com>
Subject: [PATCH] x86_64: Put more than one cpu in TARGET_CPUS
Date: Tue, 17 Oct 2006 12:11:27 -0600	[thread overview]
Message-ID: <m1u02295io.fsf_-_@ebiederm.dsl.xmission.com> (raw)
In-Reply-To: <m1y7re95o1.fsf@ebiederm.dsl.xmission.com> (Eric W. Biederman's message of "Tue, 17 Oct 2006 12:08:14 -0600")


TARGET_CPUS is the default irq routing poicy.  It specifies which cpus
the kernel should aim an irq at.  In physflat delivery mode we can
route an irq to a single cpu.  But that doesn't mean our default
policy should only be a single cpu is allowed. 

By allowing the irq routing code to select from multiple cpus this
enables systems with more irqs then we can service on a single
processor to actually work. 

I just audited and tested the code and irqbalance doesn't care, and
the io_apic.c doesn't care if we have extra cpus in the mask.
Everything will use or assume we are using the lowest numbered cpu in
the mask if we can't use them all.

So this should result in no behavior changes except on systems that need it.

Thanks for YH Lu for spotting this problem in his testing.

Cc: Yinghai Lu <yinghai.lu@amd.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 arch/x86_64/kernel/genapic_flat.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86_64/kernel/genapic_flat.c b/arch/x86_64/kernel/genapic_flat.c
index 0dfc223..7c01db8 100644
--- a/arch/x86_64/kernel/genapic_flat.c
+++ b/arch/x86_64/kernel/genapic_flat.c
@@ -153,7 +153,7 @@ struct genapic apic_flat =  {
 
 static cpumask_t physflat_target_cpus(void)
 {
-	return cpumask_of_cpu(0);
+	return cpu_online_map;
 }
 
 static cpumask_t physflat_vector_allocation_domain(int cpu)
-- 
1.4.2.rc3.g7e18e-dirty


      reply	other threads:[~2006-10-17 18:13 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-10-17 18:02 [PATCH] x86_64 irq: Use irq_domain in ioapic_retrigger_irq Eric W. Biederman
2006-10-17 18:08 ` [PATCH] x86_64: typo in __assign_irq_vector when update pos for vector and offset Eric W. Biederman
2006-10-17 18:11   ` Eric W. Biederman [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=m1u02295io.fsf_-_@ebiederm.dsl.xmission.com \
    --to=ebiederm@xmission.com \
    --cc=Natalie.Protasevich@UNISYS.com \
    --cc=ak@suse.de \
    --cc=akpm@osdl.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=torvalds@osdl.org \
    --cc=yinghai.lu@amd.com \
    /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