From: David Daney <ddaney@caviumnetworks.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-mips <linux-mips@linux-mips.org>,
Mike Travis <travis@sgi.com>
Subject: [Resend PATCH 0/2] cpumask fallout: Initialize irq_default_affinity earlier et al. (v3)
Date: Tue, 27 Jan 2009 09:48:34 -0800 [thread overview]
Message-ID: <497F48F2.90309@caviumnetworks.com> (raw)
This seems to have fallen through the cracks, so I am resending:
Now that mips/OCTEON support has been merged, this patch set has
slightly more urgency.
The interrupt affinity on OCTEON is determined by
irq_default_affinity, as that is what the code in kernel/irq/manage.c
uses to set affinity. Since for the majority of devices (Serial,
Compact Flash, Network...) we want interrupts to be handled on a
single CPU, we set irq_default_affinity to the boot CPU in init_IRQ().
The problem we have is that with the new cpumask infrastructure,
irq_default_affinity is being initialized in core_initcall which
undoes our initialization.
As I said in 2/2:
Move the initialization of irq_default_affinity to early_irq_init
as core_initcall is too late.
irq_default_affinity can be used in init_IRQ and potentially timer
and SMP init as well. All of these happen before core_initcall.
Moving the initialization to early_irq_init ensures that it is
initialized before it is used.
Mike Travis pointed out that irq_default_affinity depends on
CONFIG_GENERIC_HARDIRQS in addition to CONFIG_SMP. So to make things
consistent, I added 1/2 so that the irq_*_affinity functions and
irq_default_affinity are defined for the same conditions that they are
declared.
I Took Linus' suggestion to move init_irq_default_affinity over to
kernel/irq/handle.c, however due to the way that cpumask_*() are
defined, it is still necessary to have the ugly ifdefs, but now they
are localized to init_irq_default_affinity.
Mike Travis also suggested that alloc_bootmem_cpumask_var() be used in
preference to alloc_cpumask_var, so I incorporated that suggestion as
well.
I tested both with and without CONFIG_SMP, on mips/cavium_octeon, Mike
tested a similar(but not identical patch) on x86_64.
Changes from v2 of this set are just a small rearrangement of the
#ifdefs suggested by Ihar Hrachyshka that make the code look a bit
cleaner.
I will reply with the two patches.
David Daney (2):
Make irq_*_affinity depend on CONFIG_GENERIC_HARDIRQS too.
cpumask fallout: Initialize irq_default_affinity earlier (v3).
kernel/irq/handle.c | 16 ++++++++++++++++
kernel/irq/manage.c | 10 +---------
2 files changed, 17 insertions(+), 9 deletions(-)
next reply other threads:[~2009-01-27 17:51 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-27 17:48 David Daney [this message]
2009-01-27 17:53 ` [PATCH 1/2] Make irq_*_affinity depend on CONFIG_GENERIC_HARDIRQS too David Daney
2009-01-27 17:53 ` [PATCH 2/2] cpumask fallout: Initialize irq_default_affinity earlier (v3) David Daney
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