smp: reduce stack requirements for genapic send_IPI

From:		Mike Travis <travis@sgi.com>
To:		Ingo Molnar <mingo@elte.hu>, Andrew Morton <akpm@linux-foundation.org>
Subject:		[RFC 00/13] smp: reduce stack requirements for genapic send_IPI_mask functions
Date:		Sat, 06 Sep 2008 16:50:36 -0700
Message-ID:		<20080906235036.891970000@polaris-admin.engr.sgi.com>
Cc:		davej@codemonkey.org.uk, David Miller <davem@davemloft.net>, Eric Dumazet <dada1@cosmosbay.com>, "Eric W. Biederman" <ebiederm@xmission.com>, Jack Steiner <steiner@sgi.com>, Jeremy Fitzhardinge <jeremy@goop.org>, Jes Sorensen <jes@sgi.com>, "H. Peter Anvin" <hpa@zytor.com>, Thomas Gleixner <tglx@linutronix.de>, linux-kernel@vger.kernel.org
Archive-link:		Article, Thread


[Note: all these changes require some more testing but I wanted to solicit
comments before then, hence the "RFC" in the subject line. -thanks! Mike]

  * Change the genapic->send_IPI_mask function to accept cpumask_t pointer.

  * Add for_each_online_cpu_mask_nr to eliminate a common case of needing
    a temporary on-stack cpumask_t variable.

  * Change send_IPI_mask function in xen to use for_each_online_cpu_mask_nr().

  * Add cpumask_ptr operations.

  * Add get_cpumask_var debug operations.

  * Add global allbutself PER_CPUMASK variable.

  * Remove as many on-stack cpumask_t variables in kernel/sched.c

  * Remove as many on-stack cpumask_t variables in acpi-cpufreq.c

  * Remove as many on-stack cpumask_t variables in io_apic.c


Applies to linux-2.6.tip/master.

Signed-off-by: Mike Travis <travis@sgi.com>
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smp: reduce stack requirements for genapic send_IPI_mask functions